CDNA05561ENC_001
description
Transcript of CDNA05561ENC_001
VOL. 1 NO. 2, 3 OCTOBER 1976 PUBLISHED QUARTERLY
SPECIAL ISSUE
THE MAIZE CROP * -#6 A BASIC FEED■-.--.- -FOR BEEF PRODUCTION
ANIMAL FEED SCIENCE AND TECHNOLOGY
An International Journal
Elsevier
ANIMAL FEED SCIENCE AND TECHNOLOGY An International Scientific Journal
EDITOR-IN-CHIEF: J.F.D. Greenhalgh, Rowett Research Institute, Bucksburn, Aberdeen, Great Britain
EDITORIAL ADVISORY BOARD:
R.W. Bailey, Palmerston North, New Zealand J.R. Brethour, Hays, Kans., U.S.A. F.X. Buysse, Gontrode, Belgium J.L. Corbett, Armidale, N.S.W., Australia W.W. Cravens, Fort Wayne, Ind., U.S.A. J. Dammers, Wormerveer, The Netherlands E. Donefer, St. Anne de Bellevue, Que., Canada M.G. Jackson, Pantnagar, India M. Kirchgessner, Freising-Weihenstephan,
Federal Republic of Germany
E. Knobloch, Prague, Czechoslovakia J.K. Loosli, Ithaca, N.Y., U.S.A. D.J. Minson, Brisbane, Qld., Australia A. Schüren, Zür ich, Switzerland P. Sonne-Frederiksen, Kolding, Denmark A.J.H. Van Es, Hoorn, The Netherlands P.J. Van Soest, Ithaca, N.Y., U.S.A. R.J. Wilkins, Hurley, Great Britain
GENERAL INFORMATION
Aims and Scope. Animal Feed Science and Technology is primarily concerned wi th the publication of scientific papers dealing wi th the production, composition and nutrit ive value of feeds for animals. A t the same time it is intended to only treat matter which is of relevance to an ¡nternational readership. The journal wi l l cover such areas as the nutritive value of feeds (assessment, improvement, etc.), methods of conserving, processing and manufacturing feeds, uti l ization of feeds and the improvement of such, and the environmental effects of feeds (resultant toxici ty of animal products for man, re-cycling, etc.). I t is intended to attract readers from the disciplines of both crop and animal science, f rom the professions of research, teaching and advisory work, and from the industries of agriculture and feed manufacturing.
Publication schedule. Animal Feed Science and Technology appears quarterly; volume 1 (4 issues): 1976.
Submission of articles. Manuscripts should be submitted in triplicate to the Editorial Office of Animal Feed Science and Technology, P.O. Box 330, Amsterdam, The Netherlands.
Subscriptions. Subscription price for Volume 1 is Df l . 107.00 including postage and handling. Send your order to your usual supplier or direct to Associated Scientific Publishers, Journal Division, P.O. Box 211 , Amsterdam, The Netherlands.
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Amazon Jungle: GreenHellTbRed Desert? An Ecological Discussion of the Environmental Impact of the Highway Construction Program in the Amazon Basin.
by ROBERT J.A. GOODLAND, Ecologist, The Cary Arboretum of the New York Botanical Garden, and HOWARD S. IRWIN, President, The New York Botanical Garden; Director, The Cary Arboretum of the New York Botanical Garden.
DEVELOPMENTS IN LANDSCAPE MANAGEMENT AND URBAN PLANNING, 1 Reprinted from the journal Landscape Planning, Vol. 1, No. 2/3
1975. X + 155 pages. US $13.75/Dfl. 33.00. ISBN 0-444-41318-9
The largest of the remaining natural areas left on this planet is the vast Amazon region with its great yet extremely fragile equatorial rain-forest ecosystem - the "hylaea". The Amazonian Amerindian, divided into many sub-groups or tribes, has had the astonishing ability to persist and thrive in that ecosystem for many thousands of years without destroying it. This book summarizes and evaluates what is known about Amazonia - its history, biota, ecology, ethnology, and the repercussions of human interactions with the ecosystem. It demonstrates the unavoidable consequences of the highway network (one of which is subsequent large-scale deforestation), and discusses the likely environmental results of the large-scale cattle ranching and agriculture along these highways. Readers will readily perceive and understand that all of the authors' warnings, criticisms, and estimates of future prospects are nothing less than an entreaty to stop the irreparable destruction of a life-filled area, with its multitude of irreplaceable forms of plant and animal life, its exquisite biotic communities, and the last survivors of a unique and once great human culture.
CONTENTS: Preface (H. Sioli). Introduction. The routes of the major highways. Characteristics of the highway. Justification of the highways. History of the Development of Amazonia. History. Chronology of events concerning Amazonia. Deforestation and Agriculture. Agricultural colonization policies. The lowland tropical wet forest ecosystem. The 50% forest rule. The decline in crop yields. Meteorological impact. Alternatives to present trends. Human Ecology and Nosogeography. Diseases and the highway. Remediation. Amerindians. Amerindians of Amazonia. Amerindians affected by the highways. Improving Amerindian future. Decree governing the National Xingu Park. Fauna and Faunatlon. Value of the fauna. Composition of the fauna. Flora and Vegetation (after G.T. Prance). Physiognomic types. Summary of Amazonian vegetation types. Undiscovered species. Species extinction by exploitation. Regeneration of forest Industry. Hydroelectricity. South American "great lakes" system. Iron. Aluminium. Manganese. Cassiterite. Rio Jaro development. Conclusion. Guide to the literature. Acknowledgements. List of Acronyms. References. Index. The Authors.
ELSEVIER SCIENTIFIC PUBLISHING COMPANY P.O. Box 211, Amsterdam, The Netherlands Distributed in the U.S.A. and Canada by: AMERICAN ELSEVIER PUBLISHING COMPANY 52 Vanderbilt Ave., New York, N.Y. 10017 Prices are subiect to change without prior notice.
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LANDSCAPE PLANNING An International Journal on Landscape Ecology, Reclamation and Conservation, Outdoor Recreation and Land-Use Management.
Editor- in-Chief : A.E. WEDDLE, University of Sheffield, Dept. of Landscape Architecture, Shef f ie ld, Great Br i ta in.
Subscription Information: 1976 - Volume 3 (in 4 issues) US $39.95/Dfl . 100.00 including postage.
Vol. 1, No. 1: Editorial: Landscape Planning - aims and scope of a new journal (A.E Weddle). Unity and diversity in landscape (S.P. Tjallingii). Changing scenic values and tourist carrying capacity of national parks. An Australian example (J.D. Ovington, K.W. Groves, P.R. Stevens and M.T. Tanton). Art, science, technology, democracy and the landscape (G. Eckbo). The engineering landscape in an historical area of Central Europe (V. Vanitek and A. Hrabal). Vegetation burning and forest reservation in a segment of the forest - savanna mosaic of Nigeria: a preliminary investigation (M.U. Igbozurike).
Vol.1. Nos. 2/3: An ecological discussion of the environmental impact of the highway const ruction program in the Amazon Basin (R.J.A. Goodland and H.S. Irwin). Trees on building sites (A. Bernatzky). Environmental analysis of quarrying: an Israeli experience (R. Enis and M. Shechter).
Vol. 1, No. 4: Apprasial of visual landscape qualities in a region selected for accelerated growth (G. Wright). Microclimate and recreational value of tree plantings in deserts (G. Schiller and R. Karschon). A philosophical approach to landscape planning (G.A. Hills).
Vol. 2, No. 1 ¡Problems and objectives of landscape architecture and landscape planning in the German Democratic Republic (H. Linke and S. Thomas). Future opportunities for open space (M.D. Bradley). The accuracy of map overlays (E.B. MacDougall). Recommendations for a new Spanish Institute of Environmental Analysis (M.G. de Viedma, D. Bevan, A.E. Weddle and A. Ramos). Ecological landscape inventories and evaluation (G. Olschowy). Planning for water recreation in Israel (V. Kenyon and R. Enis).
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93
ANIMAL FEED SCIENCE AND TECHNOLOGY
An In te rna t iona l Journal
Special Issue
THE MAIZE CROP AS A BASIC FEED FOR BEEF PRODUCTION
Edited by
J.C. TAYLER and J.M. WILKINSON
The Grassland Research Institute, Hurley, Maidenhead, United Kingdom
AN INTERNATIONAL WORKING CONFERENCE in the EEC Programme of Co-ordination of Research on Beef Production
Held at the
Livestock Research Institute, Veljka Vlahovića 2, PO Box 82, 21000 NOVI SAD. Yugoslavia
June 21 - 25, 1976
Sponsored by the
COMMISSION OF THE EUROPEAN COMMUNITIES. DIRECTORATE-GENERAL FOR AGRICULTURE Division for the Co-ordination of Agricultural Research
r 3%0£B UH??,
94
Publication arranged by
The Commission of the European Communities, Directorate-General for Scientific and Technical Information and Information Management, European Centre, Kirchberg, Luxembourg.
© ECSC, EEC, EAEC, Luxembourg 1976
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information
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CONTENTS
Preface 99 Objectives and Background to Seminar 100 Opening Remarks 101
SESSION 1 SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN EACH COUNTRY 107
Southern Regions SURVEY OF THE MAIZE SITUATION IN ITALY 109 A. Romita REVIEW OF PRODUCTION AND UTILISATION OF MAIZE FOR ANIMAL NUTRITION IN YUGOSLAVIA 115 A. Sreckovic USE OF MAIZE FOR RUMINANTS AND PIG FEEDING IN GREECE 125 D. Mergounis SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN SPAIN 129 G. Gonzalez and A. Monteagudo SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN PORTUGAL 137 J.5. Da Costa Southern to Northern Continental Regions MAIZE AND ANIMAL PRODUCTION IN FRANCE 141 C. Lelong SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN SWITZERLAND '4? H. Schneeberger SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN AUSTRIA 153 B. Laber USE OF MAIZE FOR LIVESTOCK FEEDING IN GERMANY (FED. REP.). 157 E. Zimmer and J. Zscheischler SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN BELGIUM 167 B.G. Cottyn, Ch. V. Boucqué and F.X. Buysse USE OF MAIZE FOR LIVESTOCK FEEDING IN THE NETHERLANDS 177 F. de Boer Northern Regions MAIZE AS A FORAGE CROP IN DENMARK 183 Kr. G. MiSlle PROSPECTS OF GROWING MAIZE IN FINLAND 187 Seppo Pulii, Esko Poutiainen and Liisa Syrjälä THE CURRENT SITUATION REGARDING THE USE OF MAIZE IN IRELAND 195 F.J. Harte THE USE OF MAIZE FOR LIVESTOCK FEEDING IN THE UNITED KINGDOM 199 J.B. Kilkenny DISCUSSION ON SESSION 1 215
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SESSION II THE EFFECT OF AGRONOMIC FACTORS ON THE YIELD AND COMPOSITION OF THE MAIZE CROP, CONSIDERED IN RELATION TO THE METHOD OF USE OF THE CROP 227
Southern Regions - non-irrigated THE USE OF TECHNIQUES OF MAIZE CULTIVATION TO MAXIMISE FEED FOR BEEF PRODUCTION 229 R. Savie Southern Regions - irrigated CULTIVATION OF MAIZE IN IRRIGATED AREAS FDR SILAGE AND GRAIN PRODUCTION AND THEIR USE BY RUMINANTS 237 A. Monteagudo SELECTION OBJECTIVES FOR MAXIMUM YIELDS DF FEED WITH HYBRID MAIZE 245 J.L. Blanco Northern Regions EFFFCT OF AGRONOMIC FACTORS ON THE YIELD DF MAIZE AND ON ITS ' COMPOSITION IN RELATION TO ITS USE BY RUMINANTS 251 R.H. Phipps and R.F. Weiler Central Regions AGRONOMIC FACTORS AFFECTING THE GROWTH AMD COMPOSITION OF THE MAIZE PLANT 263 J. Andrieu DISCUSSION ON SESSION II 273
SESSION III EFFICIENCY OF HARVESTING AND CONSERVATION 287 EFFICIENCY OF HARVESTING AND CONSERVATION 289 E. Zimmer INFLUENCE OF ENSILING MAIZE EARS AND GRAIN ON CHEMICAL COMPOSITION, CONSERVATION LOSSES AND DIGESTIBILITY 301 R. Parigi-Bini and G.M. Chiericato EFFECT OF MAIZE SILAGE HARVEST STAGE DN YIELD, PLANT COMPOSITION AND FERMENTATION LOSSES 313 A. Giardini, F. Gaspari, M. Vecchiettini and P. Schenoni DISCUSSION ON SESSION III 327
SESSION IV NUTRITIVE VALUE FDR BEEF CATTLE OF DIETS BASED ON THE MAIZE CROP 345
ta) Effects of type of diet on energy intake and growth rate
MAIZE SILAGE WITH OR WITHOUT NPN, DEHYDRATED WHOLE-CROP MAIZF PELLETS OR HIGH-MOISTURE MAIZE GRAIN FOR FINISHING BULLS 347 Ch. V. Boucqué, B.G. Cottyn and F.X. Buysse ENERGY SUPPLEMENTATION OF MAIZE SILAGE HARVESTED AT DIFFERENT MATURITY STAGES 369 A. Giardini, M. Vecchiettini and A. Lo Bruno FACTORS INFLUENCING THE COMPOSITION AND NUTRITIVE VALUE OF ENSILED WHOLE-CROP MAIZE 381 J. Andrieu
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MAIZE GRAIN OR EARS IN CONCENTRATE DIETS FOR YOUNG FATTENING BULLS 393 S. Bacvanski
RATE OF GROWTH. FEED UTILISATION AND DIGESTIBILITY OBSERVED WITH DIETS CONTAINING ENSILED MAIZE GRAIN OR MAIZE EARS FED ALONE OR IN MIXTURES 401 D. Lanari and M. Rioni
UTILISING THE MAIZE CROP IN VARIOUS FORMS FOR BEEF PRODUCTION 417 C. Malterre and C. Lelong
NUTRITIVE VALUE OF DEHYDRATED WHOLE-CROP MAIZE 429 Y. Geay and C. MaltBrre
VOLUNTARY INTAKE AND EFFICIENCY OF UTILISATION OF WHOLE-CROP MAIZE SILAGE 441 J.M. Wilkinson
(b) Nitrogen metabolism and research techniques
THE DIGESTION AND METABOLISM OF THE ENERGY AND PROTEIN OF MAIZE 455 D. E. Beever
LEVELS, SOURCES AND METHODS OF NITROGEN SUPPLEMENTATION OF MAIZE SILAGE FOR BEEF PRODUCTION 465 A. Giardini, F. Lambertini, F. Gaspari, and A. Lo Bruno
te) Utilisation of dietary energy
THE NUTRITIVE VALUE (ENERGY) OF MAIZE SILAGE 481 A.J.H. van Es, Y. van der Honing and H.A. Boekholt DISCUSSION ON SESSION IV 485
SESSION V SYSTEMS OF PRODUCTION AND EFFICIENCY OF USE OF RESOURCES 503 (a) Systems of bull-beef production from the maize crop
EFFECT OF WEIGHT AT SLAUGHTER ON THE EFFICIENCY OF FATTENING YOUNG CATTLE 505 T. Cobic
ECONOMIC ASPECTS OF HIGH-PLANE FEEDING OF BULLS WITH MAIZE SILAGE 513 K. Walter
FOR BEEF CATTLE ALL FORMS OF MAIZE CAN BE USED 521 C. Lelong
BULL-BEEF PRODUCTION FROM THE MAIZE CROP IN ITALY IN LARGE AND SMALL UNITS 531 M. Rioni and D. Lanari
DISCUSSION ON SESSION V 545
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SESSION VI REQUIREMENTS FOR FUTURE RESEARCH 553
DISCUSSION LEADERS AND RECORDERS:
A. AGRONOMY, HARVESTING AND CONSERVATION A. Monteagudo and E. Zimmer
Β. NUTRITIVE VALUE, NITROGEN METABOLISM AND RESEARCH TECHNIQUES T. Cobic and R.J. Wilkins
C. SYSTEMS AND ECONOMICS K. Walter and A. Sreckovic
APPENDIX 1 Participants who provided details of research given in Appendix II 581
APPENDIX II Current national programmes of research in beef production from the maize crop 583
APPENDIX III List of participants 597
This special issue of Animal Feed Science and Technology was typeset for the Commission of the European Communities by Janssen Services, London. The style therefore differs in some respects from that normally used by the Elsevier Scientific Publishing Company. In particular, the shorter papers do not include an abstract.
99 PREFACE
This publication contains the Proceedings of an International Working Conference on current research and the direction of future research on the maize crop as a basic feed for beef production .
It was held in Yugoslavia on June 21st - 25th, 1976, under the auspices of the Commission of the European Communities, as part of the EEC programme of co-ordination of research on beef production.
This was the first conference on agricultural research in which the neighbouring countries of the Community in the COST group were invited to participate. COST (The Committee of Senior Officials on Scientific and Technical Research) was set up to examine means of improving co-operation and co-ordination of science and technology between the Community and third countries. The countries concerned in addition to the nine in the EEC are Austria, Finland, Greece, Norway, Portugal, Spain, Sweden, Switzerland, Turkey and Yugoslavia.
Certain proposals for concerted action on agricultural research were put to COST by Yugoslavia. The International Working Conference reported here forms a link between the existing Community programme of common and co-ordinated research and certain of the proposals on the use of the maize crop which were put forward by Yugoslavia.
The programme for the Conference was drawn up by a scientific working group comprising Dr. J.C. Tayler (Chairman, temporarily seconded to CEC during 1975); Dr. A. Sreckovic, Yugoslavia; Dr. T. Cobic, Yugoslavia; Dr. H. Honig, Germany (Fed. Rep.); Dr. D. Lanari, Italy; Professor A. Romita,Italy; Professor G. Gonzalez, Spain; Dr. A. Monteagudo, Spain; Dr. J.M. Wilkinson, United Kingdom; Mr. R. Jarrige, France; Mr. C. Béranger, France; Dr. Vaz, Portugal and Mr. P. L'Hermite, CEC.
The Commission wishes to thank the local organisers, Dr. A. Sreckovic and Dr. T. Cobic, Livestock Research Institute, Novi Sad and their colleagues for their work before and during the Conference.
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OBJECTIVES
To examine current practice in the feeding of maize to livestock; to discuss the results of recent research on the utilisation of the maize crop for beef production in relation to output per head and per ha and to the efficiency of use of energy employed in growing, harvesting and feeding the crop; to consider how far the application of research could improve efficiency of utilisation of the crop in practice, including reference to economic aspects; and to discuss the needs for further research.
BACKGROUND
The area of maize grown for feeding to cattle is high in many countries and is increasing rapidly in others. In practice the whole crop may be fed, in fresh, dehydrated or ensiled form or the ear may be harvested and fed in different forms, with or without utilisation of the stover. Widely varying amounts of protein and energy supplements are fed with maize silage and this can affect output of beef per head and per ha. Problems requiring research arise in seeking to minimise the input of protein and energy supplements and to replace these with nonprotein nitrogen ("PN) and to increase voluntary intake, which limits the use of maize as silage. There also may be interactions between genotype, sex or age of animal, and the type of maize diet.
■ Efficiency can be considered in relation to land or crop use; the energy used in growing and feeding the crop; the intake and utilisation of nutrients by the animal; and in economic terms. ? definition of research objectives would need to take account of factors which lead to maximum efficiency of use of specified resources per unit of beef produced.
101 OPENING REMARKS
Dr. A. Sreckovic
Mr. Secretary Ilic, Mr. Director Craps, ladies and gentlemen, dear guests, it is a very great pleasure and honour to welcome all of you and especially our foreign guests to this International Working Conference on Current Research and the Direction of Future Research on the Maize Crop as a Basic Feed for Beef Production. We hope you will find the arrangements for your participation to your liking and the progamme itself profitable to you. The objective of this conference is to examine current research and practice in growing and utilisation of maize in modern industrial and profitable beef production.
We hope that the results of this conference will be of great benefit both for the organisers and each participating country as well. Therefore we expect your active participation in this conference.
Ladies and gentlemen, it is my great pleasure to present Mr. Petar Ilic, Vice Secretary of Agriculture of the Executive Council of Vojvodina who will extend the official welcome.
Mr. Petar Ilic
Ladies and gentlemen, in the name of the Federal Committee of Agriculture, the Exective Council of the Assembly of Autonomous Province Vojvodina and the Provincial Secretary of Agriculture, I have the honour to greet the participants at this important International Conference.
Let me now inform you, in a few words, about the policy agreed upon and about our plans for the development of agriculture and the food industry, that during the next five years and even over a longer period will be two very important segments of the general economic development of Yugoslavia. During the period from 1976 to 1980, we are planning to increase agricultural production at a rate of 4% per annum in Yugoslavia and at 5.2% in Vojvodina. The financial basis for the realisation of this plan represents investments in agriculture and the food industry at a level of 8% of the total Yugoslav
102 investments in the economy.
The region you are in at present is one of the leading agricultural districts of our country, for Vojvodina provides more than 50% of .Yugoslavian market surpluses in wheat, maize and pork. Market surpluses in some other products are slightly lower, but still very significant. By 1980 we have planned to double the production of feed mixtures and to increase the number of cattle to total 544 000, or 20% over 1975.
The value of our cattle production is 20% of the total agricultural production and 40% of the value of total livestock production.
In addition to larger investments, better utilisation of existing capacities will contribute to the increase in Vojvodina feed production, especially completion of the Danube-Tisa-Danube hydro-system, that is expected by 1980 to have facilities for the irrigation of 100 000 ha so allowing for two harvests a year. The gradual increase of the area of land under socialistic property will be another way of contributing to the intensive food production in Vojvodina.
The development of the agro-industrial complex, the development of cattle breeding and industry based on it, enjoys special attention and is considered a most important factor of intensification, industrialisation and restructuring of the whole agricultural production and the Province's economy in general.
It is expected that by 1980 Yugoslavia will produce 11 000 000 tons of maize of which Vojvodina's part, with 3 600 000 tons, is about 37%. To achieve this plan, science will contribute largely to the development of agriculture. For instance, by the practical application of scientific principles, yields of maize grain increased from 2.08 t/ha in 1956 to 5.76 t/ha in 1975. The average milk yield of cows has increased from 2 077 litres in 1957 to 3 700 litres in 1975.
Requirements for the realisation of the five-year plan are: secure raw materials, modern technology, cadres, marketing and financial means.
I hope that, from some of the details I have put forward, areas of common interest may be found between Yugoslavia and the countries of the European Economic Community. The Government of Yugoslavia is going to support any initiative of
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scientists for international co-operation in developing agricultural production and preparing more suitable conditions for a better tomorrow.
I wish you a successful work and new contacts during and after the realisation of international projects, since we are considering this conference the beginning of successful creative endeavours of all interested partners.
Dr. A. Sreckovic
The welcome from the Commission of the European Communities will be extended by Mr. Raymond Craps, Director in the Directorate-General for Agriculture.
Mr. Raymond Craps
I would like to take this opportunity, on behalf of the Commission to thank you very warmly, Mr. Secretary, and through you the Government of your country and the Government of the people of Vojvodina, for the extremely kind invitation which has been extended to this group to come and work here on a very important subject. I wish, at the same time, to thank the people in Yugoslavia who have been working for months to organise this meeting - you Dr. Sreckovic, Dr. Cobic, and all your colleagues. I also want to thank all those who, as soon as we arrived in Yugoslavia, accepted us, showed us what your hospitality is, and made sure that we are going to start working in these few days in the best possible conditions. I should, at the same time, underline that at this meeting we are very numerous. We come not only from all the member states of the Community but include participants from nine European countries outside the Community and even an American guest, Dr.' Vetter, from the Iowa State University. It might be as well to explain that this is a meeting which has been asked for by COST (the Committee of Senior Officials in Science and Technology). It is something which has been set up by invitation from the Community to non-member countries in Europe. It has been very strongly felt within the Community from the beginning, and is now being more fully expressed, that there is a need
to have better co-ordination, better co-operation in scientific activities - co-operation which would benefit from that closer and organised link between the Community and non-member states. I think it is really important because this meeting is the very first - but certainly not the last - agricultural research activity which is being carried out in a framework which is partly outside the Community. Another feature of this meeting is that it is not an isolated activity because it is linked with existing research co-ordination programmes. In the Community the Commission has launched a series of programmes of co-ordination of agricultural research, some concentrating on protein production and improvement, others on beef production. Again we have made a link with something already in existence on which we are counting to improve co-ordination among research people and research organisations, and again, an expression of that feeling of the Community that we should push as much as possible towards the extension of co-operation within research. This means international co-operation, not restricted to its own territory, but open as much as possible to everybody who can bring something to it and profit from it. I would like very much to emphasise that aspect because I believe it is a special occasion. Of course as a layman you would not expect me to talk very much about research. Layman as I am, however, I would like to emphasise the very deep importance of the subject of this meeting, on maize production and on maize as a cattle feed. From the progress which is going to be made from this meeting, although it might take some time, I am quite sure that there is going to be a very significant contribution to the improvement of productivity on many farms and that is the purpose, I believe, of your own mission of research.
I am not going to expand further in the programme; I would like, in renewing my thanks to everybody who has worked in advance, to say that I know, at this moment, that it will be a success and also to say that we are very sorry that Mr. L'Hermite who is the man, on the side of the Commission, who has been in charge of this programme, was taken ill last week and has been unable to come - I am awfully sorry on his behalf as I am sure that he would have loved to have been here.
105 At the same time we are very lucky to have Dr. Tayler. He has done so much work; he is not going to let us get away with not working - this is a working conference. We are going to start very early in the morning. We are here to work, we are here to launch something in the form of co-ordination policy. I do, very sincerely, offer my best wishes for the success of your conference.
Dr. A. Sreckovid*
A welcome will now be extended by Professor Reljin of the Faculty of Agriculture.
Professor Reljin
Ladies and gentlemen, dear guests. Allow me to welcome, in the name of the Faculty of Agriculture, Novi Sad, this eminent meeting, and to wish you a successful working conference.
This Faculty is a relatively young school and scientific institution established only 22 years ago. However, during this period it has grown to an important educational and scientific centre. At the Faculty at the moment there are more than 1 500 students and at its 10 institutes and two experimental farms, there are 1 300 people working of which 400 are Faculty graduates. At this Faculty we have a parallel development of the research work in the field of maize production as well as in cattle breeding. Our area is a distinct maize region and meat production is largely based just on cattle nutrition with maize. Intensive beef production to a great extent utilises the maize plant as a food in various forms. Therefore, problems underlined in the programme of your scientific meeting are of outstanding practical importance for all the participants as well as on a much wider scale. However, do not forget that maize is also a very tasty and healthy food for people, especially when served together with a good piece of young beef.
Once more I wish you great success in your work and a pleasant stay in our town.
107
SESSION I
SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN EACH COUNTRY
Area of maize grown and proportion of total area grown as forage and grain crops. Quantity used for ruminants and non-ruminants, for beef cattle and dairy cattle. Varieties grown and proportionate use of different harvesting and conservation methods. Quantities and origin of maize grain imported for livestock feeding.
Beef production: form of maize feeding and supplements used in defined systems of production in relation to the climatic and economic factors which have led to the adoption of these systems.
Chairman: J.M. Wilkinson
Animal Feed Science and Technology. 1 (1976) 109114 109 lilsevier Scientific Publishing Company. Amsterdam Printed in The Netherlands
SURVEY OF THE MAIZE SITUATION IN ITALY
A. ROMITA Istituto Sperimentale per la Zootecnia Roma, Italy.
The total agricultural area in Italy is 17 461 892 ha. The irrigated area is about 3 500 000 ha and more than one third of this is utilised for maize production.
The area cultivated for the production of maize grain was 1 120 000 ha in 1963 and decreased during the following 10 years. Thereafter there has been little change (Table 1).
TABLE 1 CULTIVATED AREA AND PRODUCTION PER HECTARE OF MAIZE IN ITALY
Years
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975
Area Γ000 ha)
Hybrid maize
455.5 472.6 489.7 488.5 550.0 559.8 651.6 734.3 717.2 704.7 746.8 762.1 778.6
Local 1 Total varieties
665.0 599.7 537.9 499.2 461.6 406.7 347.5 291.5 217.3 186.4 143.5 127.9 118.3
1 120.5 1 072.3 1 027.6 987.7
1 011.6 966.5 999.1
1 025.8 934.5 891.1 890.3 890.0 896.9
Production (t/ha)
Hybrid maize
4.96 5.57 4.85 5.21 5.24 5.65 5.81 5.69 5.73 6.27 6.44 6.33 6.57
Local varieties
2.15 2.21 1.75 1.93 2.06 2.03 2.12 1.97 1.92 1.99 1.96 1.73 1.79
The production per ha increased from 4.96 tonnes (t) in 1963 to 6.57 t in 1975 (Table 1), and the total production from 3.7 million t in 1963 to 5.3 million t in 1975 (Table 2). This is due mainly to the progressive substitution of old local varieties (82.21%) with hybrid maize (70.93%); the other factor that contributed to the increase in production was improved growing techniques and particularly the better use of fertilisers
110
and pesticides, control of weeds and the widespread use of irrigation.
TABLE 2
NATIONAL PRODUCTION OF MAIZE (million tonnes)
Years
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975
Hybrid maize I Local varietie
2.260 2.632 2.376 2.545 2.909 3.162 3.784 4.179 4.111 4.419 4.807 4.821 5.115
1.432 1.325 0.941 0.965 0.951 0.829 0.735 0.575 0.417 0.371 0.282 0.222 0.212
Total
3.692
3.957
3.317
3.509
3.860
3.991
4.519
4.754
4.528
4.789
5.089
5.043
5.326
In I t a l y , maize c u l t i v a t i o n i s i n f l u e n c e d by t h e d i f f e r e n t
c l i m a t i c e n v i r o n m e n t s of t h e c o u n t r y . These d i f f e r e n c e s p r o d u c e
v a r i a t i o n b o t h i n a r e a and i n t h e v a r i e t i e s grown as i s shown
i n T a b l e 3 .
TABLE 3
MAIZE GRAIN; GEOGRAPHICAL DISTRIBUTION IN ITALY IN 1975
North Middle South Islands Total
Hybrid maize (ha) (million t)
65.327 8.971 3.418 0.146 77.863
4.430 0.489 0.186 0.010 5.114
Local varieties (ha)
0.976 1.839 8.877 0.142 11.835
(million t)
0.034 0.034 0.142 0.002 0.212
Total (ha) (million t)
66.303 10.810 19.296 0.289 89.698
4.463 0.523 0.328 0.012 5.326
I
In 1975 , 73.9% of t h e maize a r e a was in N o r t h e r n I t a l y , 12.1%
Ill in Central Italy, 13.7% in Southern Italy and 0.32% in the Islands.
Of the total maize area the percentage sown with hybrids was: 98.5%, 83.0%, 27.8% and 50.6% respectively in the north, central, south and islands.
Average production per ha was therefore higher in Northern Italy (6.73 t/ha) than in the central area (4.84 t/ha), in the south (2.67 t/ha) and in the islands (4.15 t/ha).
In 1975 the Italian regions with the largest maize area were: Veneto with 271 866 ha and Lombardia with 160 227 ha. These two areas represented 48% of the whole Italian maize area.
Maize forage, of which about 80% is used at the waxy stage of maturity, is widespread in Northern Italy (79.6%) as is shown in Table 4.
TABLE 4 MAIZE FORAGE GEOGRAPHICAL DISTRIBUTION (ha)
Northern Central Southern Islands Total
1972
217 921 45 815 8 374 1 784
273 894
1973
231 112 47 715 11 286 1 923
292 036
1974
258 726 47 609 16 335 2 599
325 165
Lombardia and Veneto cultivate 52.5% of the forage maize of the whole country.
The maize sown in Italy is produced by 15 specialised firms to give a total of about 200 individual varieties; the percentage of genetic types sown is as follows: about 45% are simple hybrids, 35% three-way hybrids and 25% four-way hybrids. The standard FAO classes utilised, in decreasing order of importance are: 700 (32%), 600 (28%), 400 (15%), 500 (12%), 200 (8%), 300 (5%).
In Northern Italy three-way hybrids and less precocious classes prevail, while in Southern Italy four-way hybrids with classes of higher precocity are more widespread. Some popular commercial varieties are: Asgrow 58, Dekalb XL 71, Funks Top, Titano, Ulisse, Dedalo.
112
In Italy some varieties of maize forage with a high level of sugar are still utilised. About 20 000 ha of these maize varieties are grown in the particular area where Parmesan cheese is made. Opaque maize is still at an experimental stage. Waxy maize is grown to a limited extent (200 - 3 000 ha) for technical uses; Energamid is the most widespread variety.
The importation of maize seed (Table 5) was at a high level in 1972 and subsequently decreased somewhat. The main countries of origin are Yugoslavia, USA, France and Romania. Our exportation of maize seed is not very important (see Table 6).
TABLE 5 IMPORT OF HYBRID MAIZE SEED (tonnes)
Yugoslavia USA Romania France Austria Germany Others Total
1972
3 761 1 695 -399 153 4
375 6 389
1973
2 403 875 -679 16 4
786 4 764
1974
1 874 1 492 817 634 --904
5 720
1975
2 034 1 388 843 779 --42
5 086
TABLE 6 EXPORT OF HYBRID MAIZE FOR SEED (tonnes)
USA Spain France Hungary Albania Germany Yugoslavia Others Total
1972 272 389 43 ---186 876
1 767
1973 -104 293 --44 19
1 283 1 693
1974 --156 386 204 121 -121 988
1975 402 98 42 ----26 568
113
Maize utilised for animal feeding and other uses, as shown in Table 7, is imported by Italy in large amounts (about 50% of our needs). USA and Argentina are the main sources. Also for this type of maize our exports (Table 8) are insignificant.
The total quantity of maize available is utilised as follows: 90.5% for animal feeding, 6.5% by industry, 2.7% for human consumption and 0.4% for seed.
TABLE 7 IMPORT OF MAIZE (tonnes)
USA Argentine Yugoslavia France Bulgaria Romania Others Total
1972
2 230 001 2 058 139
5 803 110 447 5 331
97 427 428
4 837 247
1973
2 546 541 2 020 601
48 717 100 388 7 085 137
278 764 5 002 233
1974
1 722 837 2 265 454 121 7O0 ---
105 898 4 215 890
1975
2 673 531 1 234 601
----
561 915 4 470 047
TABLE 8 EXPORTS OF MAIZE (tonnes)
France Germany Others Total
1972
3 697 180
27 155 31 033
1973
2 228 23
1 313 3 635
1974
1 353 -
95 1 453
1975
1 449 -
187 1 637
1
Maize forage is mainly ensiled and used in fattening animals that are generally slaughtered at 450 - 500 kg live weight.
To obtain a good quality carcass, animals are fed on a high plane of nutrition. Maize silage, supplemented with urea, can represent 50 - 60% of the diet while the other 40 - 50% is provided by concentrates.
The percentage of maize forage in the diets is highest for the youngest animals. Table 9 shows some rations according to Parigi-Bini (personal communication).
114
TABLE 9 SOME EXAMPLES OF RATIONS WITH MAIZE SILAGE AND GRAIN AND COB MEAL FOR INTENSIVE FATTENING
Live weight (kg)
Rations Corn silage (kg) Grain and cob meal (kg) Cereals (kg) Protein, mineral and vitamin supplement (kg)
130
1 5-6 2.5 -
1
- 220
""2 5-6 -2
1
220 - 350
Y~--J 10-12 10-12 4
.3
1 1
350 -
r~ 7-8 7 -
0.8-1 0
450
~ 2
7-8 -5
.8-1
470
Reference: Parigi-Bini, R.
Animal Feed Science and Technology. 1(1976) 115-123 I I S Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
REVIEW OF PRODUCTION AND UTILISATION OF MAIZE FOR ANIMAL NUTRITION IN YUGOSLAVIA
A. SRECKOVIC Livestock Research Institute - Novi Sad, Yugoslavia
ABSTRACT
With a total area of almost 2 400 000 ha and with a total production of nearly 9.5 million tonnes at an average yield of about 4 t/ha in 1975, Yugoslavia belongs to the 8 - 1 0 largest producers of maize in the world, and to the 2 - 4 largest producers in Europe. Until now, production of grain has been dominant in Yugoslavia, while the production of maize as a forage crop especially for silage has been less developed.
Over 75% of the area under maize is sown with home produced hybrids. Some of these hybrids achieve average yields of more than 6 - 8 t of grain per ha and on some farms even 8 - 1 0 t/ha. The work on production of new hybrids is still going on, especially those with high protein, high lysine and high oil content, as well as those with a shorter growing season to be grown as a catch crop particularly when irrigated.
Forage maize is consumed by cattle, especially dairy cows that are fed mainly on silage, and to a lesser extent on green maize or dehydrated whole maize plant. Beef cattle have until now been fed mainly on concentrate mixtures among which 3 - 4 types are dominant.
Owing to the state of the beef market and especially because of artificial barriers to trade in some countries in Europe, Yugoslavia has been obliged to examine her policy in respect of production quantitatively as well as technologically and even systems of feeding beef cattle have had to be. reconsidered. Very intensive scientific work and careful application of the results are being carried out.
INTRODUCTION
Yugoslavia belongs to the 8 - 1 0 largest producers of maize in the world and to the 2 - 4 largest producers in Europe. With
116
an area of about 2 400 000 ha, Yugoslavia contains more than 2.0% of the total area in the world sown to this crop and 19% of the area in Europe. The situation is very much the same if total production and yield per hectare are considered. In 1975, total production of maize grain was nearly 9.4 million tonnes and yield per hectare almost 4 tonnes.
These data show the considerable importance of the maize crop in Yugoslavia and they illustrate the efforts to attain one of the top positions in the world's production of maize. To increase and to improve maize production, Yugoslavia has all the necessary conditions, and our aim in the next 10 years is to increase maize production to more than 12 million tonnes and, at the same time, to reduce the area under this crop to 2 000 000 ha as well as to improve significantly the chemical composition and nutritive value of the maize grain.
Beside maize grain, Yugoslavia produces some other forms of maize which are especially important for animal nutrition such as green maize fodder, dehydrated maize harvested at the dough stage, and ensiled young maize crops at the milk and dough stage of maturity. Some parts of Yugoslavia are very convenient for maize produced as a second crop, after early harvested fodder and industrial crops, or after winter cereals. For this type of maize production, which is mainly used for silage or dehydration, irrigation is increasingly used because the second half of the summer in this country is very often without enough natural rainfall.
However, it should be emphasised that Yugoslavia has achieved great progress in the production of maize grain, while the production of other forms of maize has been less developed. Therefore, it is necessary to make special efforts in future to increase and improve these two forms of maize production.
PRODUCTION AND USE OF MAIZE
Areas and yields In the course of the last 10 years in Yugoslavia there has
been a gradual reduction in the total area of maize but also a gradual increase in total maize production. (Table 1).
117
TABLE 1 AREAS AND YIELDS OF MAIZE
Year
1966 1970 1973 1974 1975
Averages : 1973 - 1975 (3) 1966 - 1975 (10)
Total area (ha)
2 500 000 2 352 000 2 378 OOO 2 256 OOO 2 363 OOO
2 332 000 2 402 000
Total yield
(million tonnes)
8.0 6.9 8.3 8.0 9.4
8.6 7.8
Yield per ha (t)
3.2 2.9 3.5 3.6 4.0
3.7 3.2
In Yugoslavia, especially in the maize belt, maize is produced under two different types of land ownership. Society owned land is usually in blocks of 2 000 to 30 000 ha and private land in areas of 1 - 10 ha. The ratio of these two kinds of property for total arable land is about 15 : 85 and for area under maize about 10 : 90. The yield difference between these two types of farms is rather big. Areas and yields for society owned farms are shown in Table 2.
TABLE 2 AREAS AND YIELDS ON SOCIETY OWNED FARMS
Year
1966 1970 1973 1974 1975
Averages : 1973 - 1975 (3) 1966 - 1975 (10)
Total area (ha)
204 OOO 190 000 259 OOO 230 OOO 261 OOO
250 000 232 900
Total production
(million tonnes)
1.2 1.0 1.4 1.3 1.6
1.4 1.3
Yield per ha (t)
5.7 5.5 5.8 5.8 6.1
5.9 5.6
Comparing the yields obtained per hectare on the large society farms with the average yields for both kinds of farms it is not difficult to see that the difference in favour of society farms amounts to 2.0 - 2.5 t/ha; thus the yield per ha on society farms is almost twice as big as on private farms. The latter are the biggest reserves for the possible future increase of yield per hectare, as well as the total production of maize in Yugoslavia.
TABLE 3 AREAS AND YIELDS OF GREEN MAIZE FODDER
Year and ownership of farm
1964 - 1973 (10) Average 1974 - total Society farms Private farms
Regular Area (ha)
43 601 35 810 15 873 19 937
sowing time Yield (t/ha)
24.4 25.7 33.5 19.6
Stubbl Area (ha)
13 380 7 470 718
6 752
e crop Yield (t/ha)
12.2 13.5 24.2 12.4
As mentioned earlier, production of maize for roughages and other products is not as well developed as that for grain. The author of this review and many other scientific workers and producers know from their own experience that this kind of production is spreading, and under irrigation yields of 50 - 70 t/ha could be achieved from sowings at the conventional time and 30 - 50 t/ha from stubble catch crops. These results are encouraging, especially because scientific workers and producers are already applying the new maize varieties and new technologies to this kind of production, which is of great interest for livestock production, especially for cattle husbandry.
UTILISATION OF MAIZE
We do not have exact data about methods, amounts, forms and purposes of utilisation of maize in Yugoslavia. It is certain, however, that all the maize produced for roughage is fed to cattle, especially to dairy cows and heifers. Daily amounts,
119 predominantly of silage and rarely of fresh green fodder, in intensive agricultural regions are about 25 kg. In beef production and especially in fattening of young bulls (baby beef), maize as a roughage has been used in Yugoslavia in limited amounts. As a rule, under conditions of intensive production of beef, a concentrate is used which sometimes contains very small quantities of meal from the dehydrated maize plant. The concentrate is very often made of ground maize ears which constitute about 70% of the mixture which also contains a protein-mineral supplement.
More is known about the utilisation of maize grain. Of the total maize produced 3% is used for industrial processing, 21% for animal feed-industrial mixtures, 6% for export and 70% for animal feed-semi industrial mixtures (direct use on farms). From the abovementioned quantities for animal feed about 40% is consumed by pigs, 20% by cattle and about 40% by other domestic animals.
Varieties and hybrids For production of commercial maize grain, hybrid maize is
grown in the largest part of Yugoslavia. It is estimated that hybrid maize is grown on all society farms and on 70% of private farms. This means that on some areas - although in most cases only in atypical regions and farms - the old low yielding varieties of maize are grown. This is one of the reasons why private farmers achieve lower yields than society farms.
However, numerous maize hybrids occupy the real maize growing areas so that very soon the whole of the maize production will be based on hybrid seed. Many hybrids have already been been created and more are still being created in order to satisfy different and specific climatic and agro-ecological conditions of the individual regions of Yugoslavia.
Up to 1975, about 100 hybrids of all vegetation groups (100 -800) had been officially recognised in Yugoslavia. Most of these hybrids have a relatively longer growing season (groups 400 - 800) which causes difficulties in ripening and harvesting of maize grain in some regions of Yugoslavia as well as in growing this cereal as a catch crop. It is therefore necessary to create new hybrids with a shorter growing season (100 - 400) with which some important problems of growing, harvesting, dehydrating and
120
contamination of maize grain, as animal feed, will need to be solved.
From about 100 officially recognised hybrids in Yugoslavia, 40 are single cross, 5 are three-way cross and 53 are double-cross. In this paper only the most widely used maize hybrids are mentioned, which are not only grown in Yugoslavia but are also exported in large quantities as seed to other countries. These hybrids are NS SC-70, NS-696, NS SC-73 (high oil), NS SC-418F (lysine), ZP SC-1A, ZP SC-3, ZP SC-71c, OS SC-295, OS SC-661 and BC 66-25. Under normal conditions the yields of some of these hybrids are from 7 to 8 t/ha but under optimum conditions more than 10 t/ha may be achieved. Exceptionally, the yields achieved range from 13 to 15 t/ha. In 1974, 30 000 t maize seed was exported from Yugoslavia.
Besides the conventional hybrid maize, some research institutions in Yugoslavia are creating their own versions of hybrid maize with special characteristics. First of all, there are versions of "Opaque-2" with an increased lysine content. At the same time work is proceeding on some versions of hybrid maize with higher oil content and also hybrids which are to be used as forage, especially silage, as the second crop on irrigated land.
Maize and beef production In Yugoslavia, in a very specific and well organised sys
tem of production, about 500 OOO high quality young bulls are fattened per year. Most cows in the north-western, northern and central parts of Yugoslavia are of dual purpose breed for meat and milk, of Simmental type. There are over 2 million cows in these regions of Yugoslavia, of which more than 95% are on private farms. Calves for fattening are therefore produced on private farms and mostly in regions where large quantities of forages (for feeding the cows) and rather small amounts of concentrated feed are produced. Calves are reared where they were born, generally on milk or milk replacer up to 80 - 120 kg live weight or 10 - 12 weeks of age. After that, an organised purchase of calves occurs and the animals are transferred mostly to private farms, to form groups of 50 - 100 animals. The calves are kept here up to about 220 kg and then removed to big
121
industrial fattening units on the large society farms (500 - 2000 animals at one place) or to the smaller privately-owned units, (30 - 200 animals), also of an industrial type.
This organisation of the production of fattening bulls is designed to make the best use of the resources available at each stage. In phase 1 the calves are reared on milk on farms where there are large amounts of roughages for feeding to cows. The cow is then used for milk production and the calves are moved to bigger groups (phase II) in areas, where, besides roughages, there are enough concentrate feeds to grow the calves to about 220 kg. Finally, in phase III - which is up to 430 kg - the bulls are removed to industrial housing and fed generally on concentrated diets.
Until 2 - 3 years ago, when the member countries of the European Community laid an embargo on Yugoslav beef, this system ensured a high, intensive, high quality and profitable production of beef. Some years ago this kind of meat was exported to the UK as "baby beef", after that to Israel and especially to Italy and to some other countries in Europe. The meat was of top quality and the prices were very satisfactory. Technology and the system ensured both of these things. Now, the situation is more complicated and it is difficult, in such types of production, to restore the balance between new markets on the one hand and new possibilities of production on the other. Efforts are currently being made to find a scientific solution to this problem by studying new technological methods in order to be able to continue the already traditional production of high quality beef. For that reason Yugoslavia is very interested to 'take part in this conference and, perhaps, that is why Yugoslavia is host country and why we have reason to expect some benefits in the future from mutual investigations in this field.
As already stated, the fattening of bulls in Yugoslavia is usually from concentrated rations. Three typical mixtures used for this purpose are shown in Table 4.
Differences between these mixtures are not big and so they are not very important for the organisation, technology, and economy of beef production. However, in the present situation, when there are many difficulties in marketing Yugoslav beef, it is possible that some modifications to these types of rations
122
may be needed. These will depend on research results proven in practice, and also on economic analyses.
TABLE 4 COMPOSITION AND NUTRITIVE VALUE OF CONCENTRATE MIXTURES FOR FATTENING BULLS
Feed
Composition %
Maize grain Maize ear Dehydrated maize plant Dried sugar beet pulp Sunflower oil meal Minerals + premix
Starch equivalent % Digestible crude protein '■
Daily amount of feed/kg Dally gain (kg)
Type I
Ground maize
85
12 3
75.6 10.0 4 5 1.3
Type II
Ground maize ears
35 48
14 3
66.6 10.0 5 6 1.2
Type III
Dehydrated maize plant
45
30 6 16 3
63.3 10.0 6 7 1.1
Further information may be obtained from: Bacvanski, S. and Cobic, T., 1975. Razvoj i unapredjenje govedarstva í
proizvodnja govedjeg mesa i mleka u Jugoslaviji. Kongres o proizvodnji ljudske hrane u Jugoslaviji, Novi Sad.
Dumanović, J. and Delie", M., 1975. Geneticke mogućnosti poveãanja sadrzaja i pobol sanja kvaliteta proteina kukuruza. Kongres o proizvodnji ljudske hrane u Jugoslaviji, Novi Sad.
Djonović, M. and Lazin, M., 1975. Ekonomski znacaj kukuruza i pravci njegove potpunije valorizadje. Savetovanje o kukuruzu u Vojvodini, Duboka.
Milatovic, Lj., Gotlin, J. and Kauzlarić, Ljiljana, 1975. Proizvodnja, prerada i promet psenice i kukuruza, kao i njihovih preradjevina u SFRJ Kongres o proizvodnji ljudske hrane u Jugoslaviji, Novi Sad.
Petek, M. and Valosek, Visnja, 1972. Istrazivanja hranidbene vrijednosti kukuruza "Opaque2" u ishrani svinja. Agronomoske informacije, br.12/72 SZS, 1975. Ratarstvo, vocarstvo i vinogradarstvo. Statisticki bilten, 923, 1975.
123 szSf 1975. Indeks. Mesecni pregled privredne statistike SFRJ, 3, 1975
Trifunovic, V., 1975. Problemi i razvojne'mogucnosti proizvodnje kukuruza u Jugoslavije. Kongres o proizvodnji ljudske hrane u Jugoslaviji, Novi Sad.
Animal Feed Science and Technology. 1(1976) 125-127 125 Elsevier Scientific Publishing Company. Amsterdam - Printed in The Netherlands
USE OF MAIZE FOR RUMINANTS AND PIG FEEDING IN GREECE
D. MERGOUNIS Station of Agricultural Research and Cattle Breeding, Athens, Greece.
INTRODUCTION
Maize growing in Greece is becoming more and more important, on the one hand because of the development of cattle breeding in Greece and on the other hand owing to the creation of various agricultural industries using maize as a raw material.
It is the only cereal in which Greece is not self-sufficient. As maize is a very important crop for cattle feeding and contributes, with other factors, to the increase in animal production, efforts are being made to ensure that Greece becomes as self-sufficient as possible in this crop
DISTRIBUTION OF THE VARIOUS VARIETIES OF MAIZE
The cultivated area for maize grain production covers 134 600 ha, of which:
112 000 ha are cultivated with American or Greek maize hybrids 22 600 are cultivated with common maize
Greek hybrids may be divided into three categories depending on their precocity and their requirements:
1st Category: Early hybrids, earlier or of the same precocity as Min. 607 ( I 70, CI 20, CI 400) . 2nd Category: Hybrids of an intermediate precocity, a little earlier than the American hybrid Wise 641 (CI 228) 3rd Category: Late hybrids such as OHC 92. The cultivated area of each hybrid is shown in Table 1.
Maize production in Greece amounts to 540 000 tonnes. Of this quantity only 35 000 tonnes comes from common maize and the remainder comes from hybrids.
126 TABLE 1 CULTIVATED AREA OF EACH HYBRID
No.
1 2 3 4 5 6
TOTAL
Hybrid
OHC 92 CI 20 CI 70 CI 228 CI 400 Other hybrids
Cultivated area
34 28 3 36 7 2
112
200 100 COO 300 600 800
000
(ha) ¡
TABLE 2 LIVESTOCK POPULATION SPECIES IN GREECE
Species
Cattle Sheep Goats Swine
Number
1 244 416 8 403 400 4 514 000 788 400
Exploitation form
-677 800 improved 897 000 improved 602 000 fattened
7 3
-725 600 common 617 OOO common 186 400 grown
TABLE 3 PERCENTAGE CONTRIBUTION OP MAIZE IN THE FEEDING RATION OF IMPROVED LIVESTOCK
Species
Cattle Sheep Goats Swine Fowls
Percentage of maize
30-60% in the feeding mixture Basic supplementary feed Basic supplementary feed 30-70% of the grain in the diet 60% of the ration
Given that the requirement for maize by improved and local beef cattle amounts to 1 240 000 t and that the relative production in Greece is 540 000 t, the remaining 700 000 t comes
127 from imports. Most of this deficit (90%) is covered by USA importations.
We are trying to meet this deficit, firstly, by increasing the cultivated areas with maize, and secondly, by increasing the productivity per ha by improving the cultural technique and by replacing common maize with hybrids.
As far as the first aim is concerned, that is the increase of the maize area, the possibilities are very limited owing to the lack of sufficient area for cultivation. It is not possible to replace other more profitable crops with maize.
As far as the second aim is concerned we think that this is the only way of securing satisfactory results for the solution of our problem.
As maize feeding plays a leading role in meat production for beef and for other livestock we aim for, firstly, the use of maize of a very high protein value for feeding lambs and young swine, and secondly, the creation of new, very productive hybrids. For the first category of research we have no results. However, studies are currently being undertaken on:
a) Lamb fattening with maize of very high protein value (14%) in comparison with cotton seed cake and soya bean meal b) Young swine fattening with maize of very high protein value, in comparison with common maize feeding c) Determination of the nutritive value of maize of very high protein value for feeding young swine. In the second category of research the results are
satisfactory and encouraging.
Animal Feed Science and Technology. 1 (1976) 129-136 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN SPAIN 129
G. GONZALEZ Instituto de Alimentación y Productividad Animal, CSIC, Ciudad Universitaria, Madrid-3, Spain. and A. MONTEAGUDO INIA, Avda. Puerta de Hierro s/n, Madrid-3, Spain.
AREA AND YIELDS
Maize in Spain has been traditionally cultivated for grain production. In this respect the maize acreage has remained nearly constant at about 500 000 ha since 1965. Nevertheless, during the last ten years there has been a growing interest in maize as a green forage crop, which accounts for the slight increase in the total area under maize during that time (Table 1). At present nearly 600 000 ha are under maize, of which 105 000 are sown for silage. The latter figure represents nearly 6% of the total acreage of forage crops in this country.
TABLE 1 AREAS AND YIELDS OF MAIZE IN SPAIN
Year
1965 1966 1971 1972 1973 1974 1975*
Area (1000 ha) Grain
478.3 482.2 543.5 533.7 522.7 500.5 500.0
Forage
38.1 39.7 69.0 79.7 91.1 98.0 105.0
Yield (t/ha) Grain
2.39 2.39 3.78 3.60 3.90 3.98 4.0O
Forage
33.6 31.2 34.0 35.8 34.2 32.9 34.0
Production Grain
1 141.9 1 154.3 2 056.3 1 922.6 2 037.9 1 992.7 2 OOO.O
(1O0O t) Forage
1 282.0 1 227.0 2 348.0 2 701.0 3 118.0 3 229.0
-* Estimated figures
The Spanish climate makes possible the cultivation of maize for grain in most parts of the country, provided there is enough water. Nevertheless this crop is nainly concentrated in the north (Galicia and Cantábrica) where summer rainfall makes
TABLE 2 DISTRIBUTION AND YIELDS OF IRRIGATED AND NON-IRRIGATED MAIZE AREA IN SPAIN (1974)
Zone
Cantábrica Ebro Cataluña Duero Centro Levante Extremadura Andalucía Canarias
Total
Irrigated Area (1000 ha) Grain
21.1 81.8 31.9 17.9 18.5 21.2 49.6 51.0 1.8
294.8
Forage
3.8 2.4 6.8 5.3 3.1 1.9 4.5 6.9 0.9
35.6
Yields Grain
t/ha
40.0 57.1 65.8 41.5 56.1 48.8 4O.0 50.7 15.5
50.9
Total (1000 t)
84.4 467.3 209.9 74.3 103.7 103.4 198.4 253.6 2.8
1497.8
Forage t/ha
36.3 35.2 40.7 50.3 33.1 28.9 43.4 30.0 12.7
310.6
Total (1000 t)
137.9 84.5 276.7 266.6 102.6 54.9 195.3 207.0 11.4
1336.9
Non-Irrigated Area (1000 ha! Grain
182.2 1.1 12.7 0.6 0.2 4.4 0.5 2.4 1.5
205.6
Forage
46.3 1.0 7.4 2.8 0.5 0.1 1.2 2.1 0.6
62.0
Yields Grain
t/ha
25.3 26.2 17.1 21.3 18.6 9.5 5.0 8.3 6.2
24.0
Total (10O0 t)
461.5 2.9 21.4 1.3 0.4 4.1 0.2 1-9 0.9
494.6
Forage t/ha
35.6 14.1 10.8 21.5 9.2 4.7 8.5 12.6 4.6
121.6
Total (1000 t)
164.8 14.1 79.9 60.2 4.6 0.5 10.2 26.5 2.8
363.6
131 irrigation unnecessary, and in the Ebro Valley, Andalucía and Extremadura under artificial irrigation (Table 2).
Yields of grain and forage vary considerably from one region to another and even in the same region according to local conditions, cultivare used, agronomic care, etc. The national mean yield of grain has increased very sharply during the last ten years, from 2.4 in 1965 to 4.0 t/ha in 1975. The yield of forage, on the other hand, remains quite constant at about 33 t/ha. However, in good conditions yields of 11 t/ha of grain and 80 t/ha of forage have been recorded.
USE OF MAIZE CROP AND VARIETIES GROWN
Maize grain is mainly used for the production of concentrates in the feed industry: 55 - 65% for poultry, 20 - 25% for pigs and 15 - 20% for ruminants, of which some 20% is consumed by sheep. The ratio of maize used for beef to that used for dairy cattle is about 5 : 3 . Nevertheless, more than one million tonnes of maize are used by farmers in the cattle area (Cantábrica).
Local varieties sown in Spain represent 25% of the total area, the other 75% being occupied by hybrids, of which those of the FAO maturity 600 to 800 represent 65% of the total area. In 1974 12 400 tonnes of certified seed were used (Table 3).
TABLE 3 MAIZE HYBRIDS CULTIVATED IN SPAIN (1974)
FAO Index
200 300 400 500 600 700 800 900 1000 Total
Certified seed tonnes 80.5
1 242.1 224.4
1 387.0 1 842.5 2 685.9 2 957.1 1 278.5 698.8
12 396.8
% 0.6 10.0 1.8 11.2 14.9 21.7 23.9 10.3 5.6
1O0.0
132 The hybrids grown are: 80% double hybrids, 13% single cross
and 7% three-way cross. The amount of registered hybrid seed for forage only represents 10.6% of the total amount, because a large part of the area under forage maize was grown from seed of local varieties, or from the same local hybrids as those used for grain production (Table 4) .
TABLE 4 TYPE OF MAIZE HYBRID SEED (1974)
Utilisation
Grain Grain Grain Silage
Total
Type of cross
Double Three-way Single cross
-
Certified seed tonnes
9 952.9 880.0
1 563.9 1 463.2
13 860.0
%
71.8 6.3 11.3 10.6
100.0
QUANTITIES AND ORIGIN OF MAIZE GRAIN IMPORTED
The percentage of seed for grain of Spanish origin is only around 20%. The rest comes mainly from the USA but a lot of inbred lines and single crosses are cultivated in Spain with other genetic material being imported (Table 5).
Maize grain imported mainly for the feed industry has increased during the last ten years from 1.5 in 1964 to 4.5 million tonnes in 1974: 67.3% was imported from the USA and the rest from the Argentine and Brazil (Table 6). This amount represents more than twice the whole Spanish production (which was about 2.0 million tonnes in 1974) .
LIVESTOCK PRODUCTION SYSTEMS USING MAIZE AND SUPPLEMENTARY FEEDING
The feeding of maize silage, made with the whole plant when the ear is in the milk stage (or 'pastone'), to beef cattle, with appropriate supplements, is increasing on farms with artificial irrigation. The methods of feeding vary according
133
TABLE 5 ORIGIN OF MAIZE HYBRID SEED SOWN IN SPAIN (1974)
Origin
USA USA USA USA USA
Spain Spain Spain Spain
Total
Commercial name
Funks De Kalb Pioneer Asgrow Others
AD INIA Prodes DMB
Certified seed tonnes
3 194.6 2 593.6 1 494.6 1 087.9 1 611.8
1 864.1 239.2 169.9 141.1
12 396.8
%
25.7 ) 20.9 j 12.1 ) 80.7
· ■ ' !
13.3 )
15.0 ) 1 9 > 1 3 ) 19.3 1.3 ) 1.1 >
100.0
TABLE 6 AMOUNTS AND ORIGIN OF MAIZE GRAIN IMPORTED INTO SPAIN (1974)
Year
1965 1966 1971 1972 1973 1974* 1975**
Grain imported (1000 t)
1 559.9 2 428.5 2 056.7 2 382.7 2 717.6 4 061.0 4 500.0
* In 1974 the origins of maize grain imported (1000 t) were: Yugoslavia, 9.8 (0.2%); France, 10.8 (0.4%)¡ Brazil, 438.8 (10.9%); Argentine, 850.4 (21.2%); USA, 2700 (67.3%).
**Estimated.
134 to the region and season.
One system(A in Table 7) is intended to meet the target' of 12 monthsold yearlings (380 400 kg LW) using Holstein, Friesian or Brown Swiss males. Maize silage is fed ad libitum from the fifth month of age with restricted amounts of lucerne, fresh or as hay, as well as decreasing quantities of a concentrate ration of 12% digestible protein (DP) until the ninth month. From this time to slaughter the cattle are given lucerne, fresh or as hay, (4 kg DM/head/day maximum) and maize silage ad libitum (20 30 kg/head/day by the end of the period) In system Β (Table 7) the amount of a 14% DP concentrate ration is 4 kg/head/day and maize silage is given ad libitum.
Values for intake, nutritive value, and expected daily LWG for systems of feeding involving concentrates and maize silage, or maize silage and lucerne, are shown in Table 7.
Other methods of feeding are designed to produce cattle of 700 kg LW in 18 20 months with maize silage, lucerne and supplementary compound feeds as cereals (system C for summer and D for winter). The relevant data for these systems are shown in Table 8.
TABLE 7 FEEDING SYSTEMS FOR BEEF PRODUCTION (MONTHS 5 12)
Live weight (kg)
150 ISO
200 20O
275 275
350 350
425 425
System
A Β
A Β
A Β
A Β
A Β
Concen
trates (kg/day)
2.0 4.0
0.5 4.0
4.0
4.0
4.0
Alfalfa hay (kg/day)
1.0
2.5
4.0
4.0
4.0
Maize silage (kg/day)
10.0 3.0
15.0 6.0
15.0 13.5
26.0 17.5
30.0 21.0
Nutrients per head/day
DM (kg)
4.5 4.5
5.5 5.4
6.4 7.6
8.6 8.8
9.3 9.9
DP (g)
550 616
475 652
590 742
7O0 790
740 832
Feed units (Scandinavian)
4.0 3.5
4.0 4.2
4.2 5.3
5.8 6.3
6.4 7.3
Ca (g)
36 27
44 30
58 37
65 41
68 44
Ρ (g)
16 25
12 27
10 31
14 33
16 34
Expected
gain (g)
1 coo 1 050
950 1 050
900 1 300
1 loo 1 200
1 100 1 250
TABLE 8 FEEDING SYSTEMS FOR BEEF PRODUCTION (MONTHS 13 19)
Live weight (kg)
419 419
515 515
611 611
707 707
Age (months)
13 13
15 15
17 17
19 19
System
C D
C D
C D
C D
Concen
trates (kg)
3.0 3.0
4.0 5.0
4.0 5.0
4.0 5.0
Alfalfa
Hay Fresh (kg) (kg)
15 1.0
15 l.O
15 1.0
15 1.0
Maize silage (kg)
25 30
25 30
33 35
40 40
DM (kg)
9.8 9.6
10.7 11.4
12.3 12.4
13.7 13.4
Nutrients per hea
DP (g)
890 770
970 910
1 050 960
1 120 1 010
Feed units (Scandinavian)
8.2 8.0
9.2 10.0
10.3 10.7
11.3 11.4
d/day
Ca (g)
80 56
78 72
83 75
86 78
Ρ tg)
33 35
37 44
40 46
43 48
Expected daily gain (g)
1 500 1 500
1 600 1 600
1 600 1 6θΟ
1 600 1 600
Animal Feed Science and Technology. 1 (1976) 137-139 137 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN PORTUGAL
J.S. da COSTA, Estaco Zootechnica National, Santarém, Portugal
Portugal has a total area of nine million ha but only 50% (4 130 million ha) can be used for agricultural production. Nevertheless, statistical analysis showed that only 1/3 of this area is economic to use.
The area of maize grown (360 000 ha) and the production (487 000 t) has decreased by 17% and 10% respectively in the last ten years (see Table 1).
In 1974 the yield of maize was 1 350 kg/ha which was 7% higher than the normal average.
TABLE 1 MAIZE AREA, YIELD AND PRODUCTION
Year
1963-1964 1972-1973 1973-1974
1975
Area
(ha)
432 303 372 343 359 794 382 000
(%) 100 86.1 83.2 88.4
Production of Grain
(1 OOO t)
543 509 486 519
(%) 100 93.8 89.5 95.6
Yield of Grain
(kg/ha)
1 257 1 366 1 350 1 359
(%) 100 108.7 107.4 108.1
The maize growing area in Portugal stands to the north of the River Tagus where the yield of the grain is highest, and where production represents about 90% of the total. The area of forages has increased in the last few years as a result of the more advanced feeding techniques used in dairy and beef cattle production.
The quantity of maize used in animal nutrition has increased in the last few years from 599 OOO t (1972) to 628 000 t (1973) , 769 000 t (1974) and 993 000 t (1975).
Maize is mainly used as grain in animal feeding. The production of feedingstuffs is shown in Table 2 according to its utilisation by different species.
TABLE 2 FEEDINGSTUFFS PRODUCTION (t)
Species
Poultry Pigs Cattle Sheep
TOTAL
Mean 1962-1967
131 828 130 999 106 813
--
Mean 1968-1970
306 217 336 643 298 175
--
1971
396 154 454 943 319 010 7 820
-
1972
471 742 519 333 364 408 5 784
1 380 619
1973
491 564 574 873 429 573 7 606
1 526 074
1974
586 114 672 843 473 866 10 607
1 769 196
1975
593 472 767 278 436 223 5 341
1 831 008
TABLE 3 FEEDINGSTUFFS FOR BEEF AND DAIRY CATTLE
Year
Beef cattle Dairy cattle
1973
212 377 214 325
1974
271 102 199 518
1975
249 575 179 914
TABLE 4 IMPORTS OF MAIZE GRAIN
Year Tonnes Million $
1971
516 880 34.2
1972
820 752 48.7
1973
821 319 68.6
1974
1 006 329 129.9
1975
1 188 183 157.5
139
The quantity of maize given to cattle in the last four years can be estimated from the tables to be, 67 711, 72 204, 90 689 and 130 025 for 1972-75 respectively.
Statistical figures of feedingstuffs for beef and dairy cattle produced in the years 1973 to 1975 are shown in Table 3.
Maize is used in the diet of cattle in different amounts, although the recommended levels in the diets are, for beef, 50 to 60%, and for dairy cattle, 30 to 40%.
The quantities of maize grain imported for livestock feeding have increased a great deal in the last few years and have doubled in the last four years as shown in Table 4.
The main importing countries have been USA and Angola. Maize grain is generally used in all parts of the country and it is utilised both in traditional and in most recently developed farming systems. In some places it is used alone as a finishing ration for beef production.
Animal Feed Science and Technology. 1 (1976) 141-147 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
MAIZE AND ANIMAL PRODUCTION IN FRANCE
141
C. LELONG
Institut Technique des Céréales et des Fourrages, Station Expérimentale de Boigneville, 91720 Maisse, France.
MAIZE PRODUCTION
The amount of land under maize production in France has increased considerably over the last 10 years, and seems to have reached a ceiling. From 1.3 million ha in 1968, it progressed steadily, reaching 2.8 millions in 1975. (15 - 16% of the workable land - see Table 1.) This steady increase in the land used for maize growing is due largely to the introduction in the last 4 years of maize forage, the areas allotted to grain having stabilised.
TABLE 1 DEVELOPMENT OF THE AREA OF MAIZE GROWN AS FORAGE OR FOR GRAIN (million ha)
Year 1968 1970 1972 1973 1974 1975
Grain 1.02 1.48 1.90 1.95 1.91 1.96
Forage 0.31 0.40 0.58 0.62 O.80 0.87
Total 1.33 1.88 2.48 2.57 2.71 2.83
Maize grain is grown mainly in the south and on the plains of the northern central region. Maize forage is found more extensively in the animal farming regions of the west where it has undergone spectacular development. (The area under forage in Brittany and Normandy increased 8 - fold between 1968 and 1975). Figure 1 illustrates the importance of maize in the various regions and also the proportion grown as forage.
In the north of France, the lack of sun is responsible for the limited maize grain cultivation and here it is advisable to sow early varieties (FAO index lower than 200 for grain, or 250 for forage). The later varieties are most suited to
MAIZE GRAIN
MAIZE FORAGE
1975 Figure 1 Total area of maize forage and grain crops in 1968 and 1975
143
L...X Υ Χ >
FAO INDEX VARIETY ^ onn / Carghi Primeur 170 ^
z o° \ Blizzard G 188
* ~ „ J
PROPORTIONATE USE
200 ■ 2 5 0 LG LG
7 II
INRA 258 INRA 240 Adour 250 Dekalb 216 INRA 260
ΐ Star 304 INRA 400 INRA 508
530 > 6 0 0 _ Dekalb 12
250-300
300-350
350-600 ! IN \ IN ( U
Figure 2 Geographic distribution of maize varieties grown in France (FAO Index)
144 the Midi (FAO index higher, than 250). In Figure 2 it can be seen that two of these varieties cover 50% of the area planted with maize.
HARVESTING AND CONSERVATION METHODS
No exact statistics are available on the distribution of land in terms of harvesting. All maize forage is ensiled (mostly in clamp and bunker silos), apart from 10 000 ha which are dehydrated and perhaps as many used as green feed. Maize grain is preserved almost exclusively by drying, the use of moist ensiling or propionic acid treatment being rare. About a quarter of the drying is done in cribs and the remainder is artificially dried.
MAIZE UTILISATION
a) Maize forage This is given almost solely to cattle, feeding to sheep
still being in the experimental stage. Although it is not known with any certainty what proportion is used for beef or milk production, we venture an estimate of less than one third, perhaps a quarter, destined for beef cattle feeding.
b) Maize grain Very little is imported (about 4% of what is available)
and about half of the grain produced goes towards animal feeding. The other half is either exported (about 40%) or used industrially (7%) (See Figure 3).
More than 60% of the maize grain consumed by animals is in the form of mixed feeds produced by the feed industry, and about 40% is consumed on the farms where it is grown. We have no information on which animals consume this latter percentage - pigs and cattle would seem likely. On the other hand, the maize purchased by the compound feed industry is intended mainly for poultry (57% in 1972 - 73) and pigs (42% in 1972 -1973). Maize is primarily a poultry cereal and the amounts used for poultry feed are increasing. Nevertheless, maize provides only a small proportion of the total feed consumed by livestock in spite of its attractive price in comparison
PRODUCTION
IMPORTED
SUNDRIES
INDUSTR
ARMS
EXPORTED
COMPOUNDED FEEDS
ANIMAL FEEDING UTILISATION
Figure 3 Production and utilisation of maize yrain in France. (Average of crops grown in 1972/73 and 1973/74) £
146 with other cereals.
Table 2 emphasises the increasing importance of maize among the cereals used for animal consumption. In 197 3 - 74 maize had caught up with barley and overtaken wheat as a result of the purchasing policies of the compound feed manufacturers. Wheat, and especially barley, however remain the cereals which are the most consumed on the farms where they are produced.
TABLE 2 COMPARISON BETWEEN MAIZE, WHEAT AND BARLEY GRAIN AS ANIMAL FEEDS
Year
1965 - 66 1969 - 70 1973 - 74
Maize
1000 t
2.31 2.99 5.29
% 17 19 31
Wheat
1000 t
4.09 4.60 3.79
% 30 29 22
Barley
1000 t
4.66 5.56 5.27
% 34 36 31
Total cereals
1000 t
13.83 15.60 17.22
% 100 100 100
(Reference AGPB and Eurostat)
FORM OF MAIZE FEEDING
Maize silage rarely constitutes the complete winter diet for dairy cattle. It is fed together with hay, cabbages, or other ensiled or dehydrated fodder for part or all of the winter. With high-producing cows, supplementary energy is provided by one of the cereals, maize, wheat, barley,or a mixture of wheat and barley. Urea and minerals are sometimes added to maize silage before ensiling.
For beef cattle production, maize silage constitutes the major part of the feed ration and is often supplemented with 1 or 2 kg of dry cereal per day (except in early maturing breeds such as Friesians). One kg of soya or groundnut meal provides the necessary nitrogen, and sometimes small quantities of hay are added. Some farmers use diets of higher energy concentration. These may include maize silage with large quantities of dry or moist cereals, or dried ears, ear silage moist or dry grain and hay or straw. This practice, however, is not widespread.
147 Fattening feeds are given to bulls from the time they are
weaned (at 3 months of age in dairy breeds, or 8 or 9 months of age in beef breeds) to ensure rapid rates of growth. They may also be given to castrated animals after one or two seasons at pasture.
This is a brief glimpse of the production and use of maize in France. Much complementary information is needed to provide explanations and details of what has been said. This suffices to give an overall impression of the maize situation in France in relation to that in other European countries.
Animal Feed Science and Technology. 1(1976) 149151 149 Elsevier Scientific Publishing Company, Amsterdam Printed in The Netherlands
SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN SWITZERLAND
H. SCHNEEBERGER Swiss Federal Research Station for Animal Production, Grangeneuve 1725 Posieux FR, Switzerland.
AREA
In Switzerland the maize area has increased 10fold over the last 20 years (wholecrop, 7fold; grain maize, including maizecobmix, 20fold). During the same period of time the yield of maize grain increased from 3 500 to 6 500 kg/ha (85% dry matter). The large expansion of the maize area is partly due to the provision of a cultivation subsidy.
The proportion of maize in the total arable land increased from 1.6% in 1955 to about 17% in 1975. The expansion occurred mostly at the cost of the cultivation of potatoes.
TABLE 1 DEVELOPMENT OF THE MAIZE AREA IN SWITZERLAND
Year
1955 1965 1970 1975*
Maize (ha)
Whole crop
3 000 5 200 11 200 22 400
Grain (incl. maize
cobmix)
1 100 4 300 9 3O0 21 300
Proportion of arable
Maize
1.6 3.9 8.3 17.0
Potatoes
19.6 15.0 12.2 9.0
land (%)
Cereals
65.2 68.2 65.9 62.0
♦Provisional figures Source: Statistical inquiries and estimations 1975, published by the Swiss Farmers Union, Brugg.
150
APPORTIONMENT OF MAIZE PRODUCTION, INCLUDING MAIZE IMPORTS TO DIFFERENT ANIMAL CATEGORIES
No official information exists on the quantities of maize which are fed to different animal categories in our country. The following figures present estimated values for the year 1975. Accordingly, the production of whole crop maize amounted to 336 OOO tons dry matter (22 400 ha χ 15 t dry matter per ha). This feed was only used for ruminants, and of that approximately one third for dairy cattle and two thirds for beef cattle.
By estimation in 1975, there were about 385 000 t of maize grain (maize-cob-mix included) available. Approximately two thirds of this quantity was imported and one third produced in the country. Of the imported maize, about 95% was probably used for feeding non-ruminants (pigs, poultry), whereas 80% of home-produced maize grain and maize-cob-mix was given to cattle (65% to beef cattle, 15% to dairy cattle).
VARIETIES
In Switzerland the cultivation of mid-early varieties is dominant. After extensive evaluation (cultivation during three years in ten different places), the most suitable varieties are accepted in the standard list of the Swiss Federation for Seed Producers.
In practice the following varieties are most common: Grain-maize (including maize-cob-mix) = ORLA 264 and 312
INRA 258 LG 11
Maize for silage (whole crop) = ORLA 2 70 and 2 30 LG 11
The seed used in 1975 is estimated at 1 500 t. One half of this quantity is provided by home production, the other by imports (mainly from France).
HARVESTING AND CONSERVATION METHODS
No statistical information exists in our country on this subject so that we have to be content with estimates.
151 Only about 2% of the whole-crop maize produced is used as
green fodder, about 3% is artificially dried and the remaining 95% is used for silage.
Of the cultivated varieties of grain-maize, about 70% is harvested as "ripe" maize and about 30% as maize-cob-mix and high-moisture grain for silage.
USE OF MAIZE FOR BEEF CATTLE
As a basic feed for beef cattle, maize can be used in different forms :
whole plant - fresh - for silage - artificially dried
maize-cob-mix or ground high-moisture-maize grain - for silage
The feeding of green whole-crop maize to fattening animals is limited to 4 - 6 weeks in autumn. As mentioned, only about 2% of the whole-crop maize is fed as green fodder.
Maize silage (whole plant) is the most important basic feed for beef cattle. The harvest occurs at the dough to mealy endosperm stage, the crop being chopped (approximately 5mm) and conserved mostly in tower silos (capacity 30 to 200m3). A supplement of concentrated feed, rich in protein is necessary. The daily ration of this supplement varies between 1 and 4 kg per animal, according to the quality of the silage, the fattening intensity and the sex of the animal.
On some farms, maize silage is fed together with grass silage rich in protein.
The artificially dried whole maize plant is used as a supplementary feed for dairy cattle or fattening animals at pasture in quantities of 1 to 2 kg per animal per day. As a basic feed in fattening, artificially dried maize is too expensive.
Maize-cob-mix and ground high-moisture-maize grain are partly used on larger fattening farms for young bulls in the west part of Switzerland, where climatic conditions are favourable for the ripening of maize. This feed is then supplemented by protein concentrate, and hay or straw. This feeding system requires more arable land for the same number of animals, but needs less silo room than for the feeding of whole-crop silage.
Animai Feed Science and Technology. 1 (1976) 153-155 153 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN AUSTRIA
B. LABER No. Landes-Landwirtschaftskammer 1014 Wein I., Lowelstrasse 16, Austria.
As in other European countries, the area of maize in Austria has increased rapidly during the last ten years.
Development of the area of maize in recent years. a) Maize grain 1965 49 981 ha
1975 143 743 ha b) Maize for forage 1972 52 387 ha
1975 80 255 ha Relation between roughage area and feed grains area in 1974 Roughage area 1 333 968 ha Feed grains area excluding maize 444 249 ha Total area of maize 221 776 ha There is no exact survey of the use of maize for ruminants
and non-ruminants. The use can only be estimated. Eighty per cent of the maize grain is used for pigs and
poultry and only 20% for cattle, of which half is used for dairy cattle and half for beef cattle. The total production of maize grain in the year 1975 was 980 523 t, with an average yield of 6.8 t/ha. (15% moisture content).
Maize forage is given only to cattle. In 1975 the total production of maize forage was 4.3 million tons, with an average yield of 54.3 t/ha.
The most common varieties of maize are: Early varieties INRA 2 58
LG 11 AUSTRIA 290
Other varieties AUSTRIA 390 STAR 304 AUSTRIA 430 FUNKS G 350
Seeding rate Rainy area 90 000 - 100 000 plants/ha Dry area 55 000 - 85 000 plants/ha
154
Plants/ha Rainy area 70 000 - 80 000 plants Dry area 50 000 - 70 000 plants Fertiliser recommendation Maize grain normal yield high yield Ν 120 kg/ha 160 kg/ha* P2°5 110 kg/ha 160 kg/ha K20 200 kg/ha 280 kg/ha Maize forage normal yield high yield Ν 150 kg/ha* 200 kg/ha* P 20 5 100 kg/ha 150 kg/ha K20 200 kg/ha 280 kg/ha *two applications
CONSERVATION METHODS
Maize grain About 80% of the yield is preserved by drying and about
20% is ensiled. The quantity ensiled is tending to increase. Maize forage Nearly all maize forage is ensiled, mostly in trench silos,
but also in tower silos.
NUTRIENT CONTENT
On the basis of a large number of analyses, the nutrient content of maize grain can be estimated to be about 820 g/kg.
The dry matter content of maize silage (forage) averages about 28% with a starch equivalent content of about 170 and a content of protein of about 13% of the DM.
Change in prices for maize and barley. Maize grain Barley
1972 236.45 Schilling/lOOkg 236.85 Schilling/lOOkg 1975 285.83 Schilling/lOOkg 281.58 Schilling/lOOkg Quantities and origin of maize grain imported for livestock feeding 1974/75 20 800 t (from Hungary and USA) 1973/74 15 900 t 1972/73 39 000 t
155
BEEF PRODUCTION
Austria produces more beef than can be used in home consumption and therefore about 60 000 beef cattle have to be exported. The best beef breed in Austria is the Simmental and about 90% of beef is produced with this breed.
The following two systems of beef production are used: a) Fattening young cattle with a live weight about
300 - 400 kg up to a live weight about 600 - 650 kg. b) Fattening bull calves from about 100 kg live weight
up to a live weight of about 600 - 650 kg. For system a) sugar beet-top silage is sometimes used with potato pulp. For system b) maize silage (forage) is the basic ration.
Grass silage is not used much for beef cattle because it is rather expensive compared to maize silage but also the concentration of nutrients is not so high.
Fattening of bulls with concentrates is of no importance, because of the relatively high prices of concentrates.
FEEDING SYSTEMS WITH MAIZE SILAGE
Maize silage is fed twice daily ad libitum. The daily feed consumption averages about 15 - 16 kg per head. Soya bean meal is the most common protein supplement. In the final fattening period feed grains are also given at 1 - 2 kg per head per day. The daily ration of soya bean meal during the total feeding period averages 1 kg per head. Minerals are given at an average level of 0.08 kg per head. The use of urea is of no importance and its cost is calculated in relation to that of soya bean meal.
Total feed consumption of a young bull from 100 kg - 600 kg live weight averages :
7 500 kg maize silage 500 kg soya bean meal 450 kg feed grains 40 kg minerals
Depending on the quality of maize silage, 7 - 9 young bulls can be fed per ha.
Animal Feed Science and Technology. 1(1976) 157-165 157 Mscvier Scientific Publishing Company, Amsterdam — Printed in The Netherlands
USE OF MAIZE FOR LIVESTOCK FEEDING IN THE FEDERAL REPUBLIC OF GERMANY E. ZIMMER Institut für Grünlandwirtschaft, Futterbau und Futterkonservierung der Forschungsanstalt für Landwirtschaft D-3300 Braunschweig, Bundesallee 50, West Germany and J. ZSCHEISCHLER Bayerische Landesanstalt für Bodenkultur und Pflanzenbau D-8050 Freising-Weihenstephan, Vöttingerstr. 38, West Germany.
ABSTRACT
The area of maize is increasing continually in the Federal Republic of Germany because of better adaptation to the temperate, humid climate of the country.
Maize for grain is now planted on 108 000 ha, yielding 5.1 t/ha with variation from year to year of 5.8%, which is comparable to other grain species. Its position now is 2.1% of the total grain area.
Maize for silage in 1975 occupied 430 000 ha, yielding approximately 12.1 t/ha DM. This crop occupies 7.6% of total forage or 33.6% of fodder crops, excluding grassland. Climatic conditions allow the sowing of early to medium-early varieties for grain, and medium-early to medium-late varieties for silage. The nutritive value of the whole plant is not affected very much by the region.
Drygrain and high moisture corn are both harvested by combine. Corn-cob mix and picked, chopped ears are also used as feeds for beef cattle. Conservation is done by drying, ensiling, or ensiling after treatment with acid. Whole-crop silage is harvested within a range of 18 - 30% DM, using precision chopping, preferably at the dough stage of maturity. Conservation methods vary according to type of silo, farm size, availability of capital, manpower and method of utilisation. Production is 0.5 - 0.6 million tonnes of grain; importation is 3.2 million tonnes. Two thirds of home production is used for fattening pigs. Almost all of the whole-crop maize ia utilised by ruminants, but no estimated figure for particular use in milk or beef production can be given.
158 Fattening young bulls within 18 - 20 months up to 550 -
600 kg live weight on the basis of maize silage to appetite, supplemented by 1 - 3 kg concentrate, is common practice.
Feedlot systems on large farms are an exception. Fattening of small or medium-sized groups of animals is in barns, but also in loose housing systems. Hand feeding, mixing trailers and food troughs of all kinds are used.
Maize is considered as a crop with increasing significance, characterised by a high degree of interest by farmers and advisory services, as well as by research organisations in the country.
AREA OF MAIZE GROWN (Figure 1)
A combination of early maturity and high yield has pushed the acreage of maize in FRG further north, beyond the classical ecological sites in southern and south-western Germany. Increasing DM yields and average level of maturity are characteristics of adaptation to north-western conditions.
a ¿00 ·
» 1.1
IJ , / l i
0^—0 io rfTAfls TSE 7
1 7
l-"°' ΪΠ
'-Ί
FOR sinee 1 1 1 1
^ o
s
5
t
, ü * i u | _ f i l l , , FOR GRAIN
I—«—rilIl
156« 59 70 71 7> 7Ì 7< 75
Fig .
Si SS 70 71 72 7J 7< 73
1 Area and yield of maize in the Federal Republic of Germany
159 Maize for grain has been sown on about 108 000 ha for the
past five years. Approximately 70% of this is located in the southern states of Bavaria, Baden-Württemberg and Rheinland-Pfalz. At present development has come to a standstill. Competition with small grains on the basis of attainable yields as well as a limited number of early maturing varieties might be limiting factors. Yields averaged 5.13 + 0.296 t/ha over a six year period (Table 1). The coefficient of variation of 5.8% does not indicate a greater fluctuation in yield than with other grain crops. For a long time the trend for yields to increase was estimated to be 0.098 t/ha of grain per year.
TABLE l GRAIN YIELD IN FRG (1970 - 1975)
Maize Winter barley Spring barley Oats Winter wheat Spring wheat Rye
Yield (t/ha)
5.13 4.43 3.51 3.63 4.41 4.07 3.45
SD (%)
5.8 8.6 8.8 9.7 8.6 8.2 5.2
Maize for silage or green feeding is increasing in area continuously. Approximately two-thirds is located in the south and the rate of growth there is higher than elsewhere. However one can imagine from testing programmes that better adapted varieties will change the situation for northern regions.
Yields are 43.3 t/ha fresh material. The coefficient of 5% for yield variation is low. Including DM values from seed testing stations dry matter yield can be calculated to be 12.1 t/ha (Table 2). Rate of growth was estimated to be 0.34 t/ha per year.
Compared with other fodder crops maize is highly superior.
160
TABLE 2
YIELDS OF FORAGE CROPS (1970 - 1975)
Maize Clover, clover/grass Alfalfa Ley Grass]and
Yield (t/ha)
12.14 6.63 6.87 5.97 5.89
SD (%)
7.3* 2.3 1.8 2.8 2.5
*Years 1969 - 1975, DM con ten t 1975 es t ima ted
Source: BML 1975; Haas 1976; Z s c h e i s c h l e r 1976
RELATION TO OTHER CROPS ( F i g u r e 2)
Maize f o r g r a i n now o c c u p i e s 2.1% of g r a i n a r e a or 3.8% of f o d d e r - g r a i n a r e a . Maize f o r s i l a g e now o c c u p i e s 7.6% of t o t a l f o r a g e - c r o p s and g r a s s l a n d , or 33.6% of f o r a g e - c r o p l a n d .
βΚΛΙΝ 5 298 0 00 Hi FORAGE CROPS < 997 000 HA
Fig. 2 Area of maize in relation to grain or forage crops, Federal Republic of Germany, 1974.
161
VARIETIES GROWN
The temperate and humid climate allows planting of early (FAO = 200) to medium-early (FAO 200 - 240) maturing varieties for grain, and medium-early (FAO 200 - 240) to medium-late (FAO 250 - 290) maturing varieties for silage or green-feeding.
The demand for maize for a certain climate is reflected in typical yields and yield variation for particular regions. On the other hand, nutritive value is not affected very much by maturity type (Table 3) (Zimmer, 1973) .
TABLE 3 YIELD AND NUTRITIVE VALUE OF DIFFERENT MATURITY TYPES OF WHOLE-CROP MAIZE
DM yield t/ha DM% SE/DM SE yield t/ha
DM yield t/ha DM% SE/DM SE yield t/ha
Maturity type: mid early 10.7 - 14.5 23.8 - 29.1 64.2 - 66.7 6.9 - 9.5
Maturity type: mid late 10.8 - 15.2 22.3 - 26.7 62.8 - 65.4 6.9 - 9.8
S% 15.0 10.0 1.9
15.7
S% 16.8 9.0 2.0 17.6
Even when comparing r e s u l t s between d i f f e r e n t c o u n t r i e s , one w i l l n o t i c e the same tendency (Table 4) (Zimmer, 1973).
TABLE 4 YIELD AND NUTRITIVE VALUE OF WHOLE-CROP MAIZE IN DIFFERENT REGIONS OF EUROPE
Region
Southern England Netherlands Germany
Northern Italy
Author
Thomson (1968) Dijkstra (1971) Liesegang (1965)
Giardini (1964)
Coefficient of variation, S%
Type
mid-early mid-late mid-early mid-late mid-late
DM%
23.1 18.4 26.4 24.5 33.0
19.9
DM t/ha
13.23 12.5 12.58 13.0 11.87
5.9
SE/100DM
63.3 60.6 65.5 64.1 66.2
3.2
SE t/ha 8.4 7.6 8.2 8.3 7.8
5.0
162
HARVESTING AND CONSERVATION ( T a b l e 5)
TABLE 5
HARVESTING AND CONSERVATION OF MAIZE
High
moisture
grain
Maize whole crop
Stems and leaves
Maturity moisture cont. <25 25-35 35-50
>50
<70 ~75 <80
<50
Harvesting by
Combine Combine Combine
Picker-chopper
Chopper 1 - 3
rows
Chopper
Product
Grain HM-grain Corncob-mix Corncob-mix
Maize silage 6-12mm
Stalklage 6-12mm
Crude fibre
2-3 2-3 4-8
10-15
<20 20-22 22-24
>33
Conservation Ensiling
Drying Air- Con Org. tight vent.Acids
X X X ? X X X
X X ?
? X
(X) X (X) (X) (X) X (X) X
X
? Not recommended for technical or economic reasons (X) Possible, regarding certain technical or economic conditions.
Harvesting and conservation of maize grain demanded nev/ technology, because the moisture content is normally high in certain regions and years, exceeding the capability of combine harvesters. The harvesting method, therefore, depends first of all on moisture content. In the case of pig production one also has to consider the crude-fibre content as a limiting factor in feeding the material. Conservation method, on the other hand, will be affected by:
a) moisture content: whether drying or high-moisture conservation is suitable
b) availability of capital :
c) feeding system:
whether airtight, conventional storage is preferred or organic acid treatment suits the particular farm conditions whether year round or limited winter feeding is necessary.
163 From the above it is clear that generalised recommendations are not very useful.
Maize for silage is harvested within a range of 18 - 30% (or more) DM content, depending on variety and weather. The dough stage is considered to be the best. Precision chopping with a theoretical length of 4 - 8mm and affecting almost all kernels to prevent loss is recommended.
In relation to the area of maize, tractor mounted one-row choppers are used, or 2 to 4-row field choppers demanding a high tractor power. Type of silos, such as temporary clamp, plastic covered trench or bunker, tower, and the particular unloading technique are influenced by farm size, manpower, capital and feeding system.
Nutritive losses in different silo-types and the risk of heating during unloading is considered to be an important factor by farmers from the feeding and economic standpoint (Zimmer, 1973). General trends are towards bunker silos on bigger farms and mechanised tower silos on the fau-.ily farms which have a shortage of manpower and a demand for high and uniform quality in the silage.
Additions of 0.5% urea or Maisfertil (BASF - urea/mineral mix) are widely used. Prosil (based on ammonia) is under experimentation (Honig, 1975). Addition of organic acids, or other additives to stabilise fermentation and minimise nutrient losses, is still limited to special cases because maize is considered a crop which is easy to ensile. These questions are under discussion and experimentation.
In a few cases whole-plant maize is artificially dried for special purposes and examination.
Experimental work is being carried out on the ensiling of stalks and leaves for co-called stalklage. The same technology is used as with whole-crop maize silage, but open questions are the nutritive value, feeding regime, course of fermentation and stability of the product.
UTILISATION OF THE MAIZE HARVEST The production of 0.5 - 0.6 million tonnes of grain is in
contrast to an import of 3.2 million tonnes per year (1971/74). The major places of origin of the imported grain are France and the USA.
164 Consumption of home grown maize is fairly constant at 0.35
million tonnes. Sale to industry or between farms therefore only reaches 25 - 40% of the total amount produced. Compared to the volume of imported grain this is negligible (Haas, 1976). Utilisation takes place as dry corn or high moisture corn, mostly for fattening pigs. The proportion of grain given to ruminants is low. On the other hand, ruminants utilise almost all the maize silage and green maize. The amounts used in milk or beef production cannot be estimated.
FEEDING FOR BEEF PRODUCTION
Fattening young bulls within 18 - 20 months up to 550 - 600 kg live weight, using maize silage ad libitum as the only roughage, or in combination with other silages, is common practice. Supplementation with energy is necessary in the form of 1 - 3 kg of concentrate. Corn-cob mix is used instead of other concentrates where large areas of maize are available for harvesting by different methods.
The requirement of the beef animal for additional digestible crude protein is normally met by soya bean meal, horse bean, brewer's grains etc. Use of urea is calculated in competition with soya bean meal. Farmers furthermore pay a great deal of attention to mineral and vitamin supplementation. Maize silage, harvested at the dough stage and with the ear accounting for 45% of total dry yield, has to be complemented daily by approximately 40 g calcium, 16 g phosphorus, 6 g sodium and 4 000 IU vitamin A (Burgstaller, 1975).
Regarding the farm structure in Germany, the fattening of small or medium numbers of animals in barns, or of medium-sized groups in loose housing systems, is common. Feedlot systems on large farms are an exception. Therefore one will find most feeding systems based on hand feeding, using special transportation and / or mixing trailers and food troughs.
OUTLOOK
The breeding of new varieties with better adaptation and/or higher yields, or with .modified quality (lysine, net energy.
165 digestible fibre) demonstrates progress in seed testing programmes around the country. Research activities, particularly in the north-west, show possibilities of maize production which will soon be taken up by farmers because of certain advantages of this crop.
Interest by farmers is high, as well as a readiness for on-farm experimentation in plant production, protection, harvesting and conservation techniques, utilisation and feeding.
This complements many research activities in State and Federal institutions, from which one may consider maize in Germany as a crop which still has a big future.
REFERENCES
Anonymous 1976. Zur Sortenwahl bei Mais Ztschr. Mais, 1976, No. 1, 16-18. BML 1975. Statistisches Jahrbuch über Ernährung, Landwirtschaft und
Forsten, Paul Parey Verlag. Bundessortenamt, 1974. Beschreibende Sortenliste A. Strothe Verlag
Hannover. Burgstaller, G., 1974. Silomais - Bullenmast Ztschr. Mais, 1974, No.4, 3-4. Haas, G„, 1976. Deutsches Maiskomitee, persönliche information. Honig, H. and Zimmer, E., 1975. Experiments on the use of Prosil as an NPN-
additive for maize silages, (als Manuskript veröffentlicht) Report given at the Second Annual Silage Conference, July, 1975, Ann Arbor, USA.
Zimmer, E., 1973. Nährwert von Mais im frischen, silierten ung getrockneten Zustand (als Manuskript veröffentlicht) Report given at the European Association for Animal Production, Vienna, Sept. 1973.
Zscheischler, J., 1976. Früher reifende Sorten machen den Maisanbau sicherer. Bayr'. ldw. Wochenblatt, No. 6, 7. Febr. 1976.
Animal Feed Science and Technology, 1 (1976) 167175 167 Hisevier Scientific Publishing Company, Amsterdam Printed in The Netherlands
SURVEY OF THE USE OF MAIZE FOR LIVESTOCK FEEDING IN BELGIUM
B.G. COTTYN. CH.V. BOUCQUE and F.X. BUYSSE National Institute for Animal Nutrition, Scheideweg 12, B9231 Gontrode, Belgium.
AREA OF MAIZE GROWN IN BELGIUM
The use of maize as a basic feedstuff in ruminant feeding has increased very rapidly in Belgium in recent years. According to statistics supplied by NIS Brussels (1975) and LEI Brussels (1975) , the area of doughdent maize harvested together with the production of maize grain over the last 10 years in Belgium shows the following picture (Table 1).
TABLE 1 AREAS AND YIELDS OF MAIZE IN BELGIUM ( 1 9 6 5 7 6 )
1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 19 76
Maize area
Forage
5 358 5 913 6 345 6 716 10 655 17 828 24 748 33 287 40 397 49 483 66 018
Grain
450 504 560 7O0 865
1 954 3 265 4 558 4 222 4 879 6 369
— ' —1 (ha)
Total
5 808 6 417 6 905 7 416 11 520 19 782 28 013 37 845 44 619 54 362 72 387 80 000
Maize as
Total forage area
16.3 17.4 18.9 22.8 34.1 52.6 63.6 72.9 80.1 86.2 92.8
percent of
Forage area + leys
2.0 2.2 2.4 2.7 4.3 7.0 10.0 13.8 16.5 20.6
Yield (t/ha)
Total grain crops
1.1 1.3 1.4 1.5 2.4
• 4.3 6.2 8.2 9.3 12.6
Forage
47.3 52.3 53.7 52.6 54.5 52.8 51.0 45.0 43.8 48.0 50.1
Grain
4.46 4.42 4.67 4.50 4.78 5.18 5.63 4.04 6.29 5.Ol 5.88
In 1965. the t o t a l maize product ion (maize forage + maize grain) amounted t o 5 808 ha, by 1970 t h i s area had increased
Communication RW ΛΓ 354 of the above Institute.
168
to 19 782 ha (χ 3.4) and by 1975, maize production had increased to 72 387 ha (x 3.7).
Since the development of precocious hybrids, all Belgian agriculture districts, with probably the plateaus of the Ardennes excepted, are suitable for doughdent maize production.
From the 1.48 million ha of agricultural land in Belgium in 1975, 847 471 ha was destined for direct forage production, 575 892 ha for arable land, 50 454 ha for horticulture and 6 456 ha for other uses. The principal change compared with 1974 concerns the production of doughdent maize which increased from 3.3% of the total area in 1974 to 4.5% in 1975.
Increased herd size, limited land resources, efficient integral mechanisation from sowing to feeding and high levels of production, undoubtedly promoted maize expansion. Moreover, cattle feeders have become increasingly aware of the excellent forage characteristics of maize silage and its high energy value for ruminant rations. Maize, used as whole plant silage, has a greater energy content than any other forage, fodder beet excepted. When properly ensiled, maize silage is a highly palatable feed which gives high levels of intake by beef and dairy cattle.
As shown in Table 1, maize as a proportion of total forage production (maize, clover, lucerne, fodder rye and kale) increased very sharply from 16.3% in 1965 to 52.6% in 1970 and 92.8% in 1975. Comparing the total area of maize with the total forage area + temporary grassland (leys) we find an increase from 2.0% in 1965 to 20.6% in 1974. The proportion of maize in the total grain crops (maize included) increased from 1.1% in 1965 to 12.6% in 1974.
The change in yield per ha of maize forage and maize grain during the same period (196575) is presented in Table 1.
QUANTITIES USED FOR DIFFERENT TYPES OF ANIMALS
Maize can be used in three different forms as a basic feed for dairy and beef cattle: maize silage, dehydrated whole maize plant pellets and high moisture maize grain. We can estimate the amount of high moisture grain given as a high energy basic feed to beef cattle in 1975 as only about 100 ha (588 t) at the most.
169 From the c 66 000 ha forage maize harvested in 1975, only
about 300 ha (15 0O0 t) was dehydrated and pelleted. The greatest quantity, about 3 300 000 t, was therefore ensiled.
In the Flemish country, closely linked with dairy production c 80% of this maize silage is given to dairy cattle and young heifers and only 20% to beef cattle. In the middle and south of Belgium, with its larger farms, 55% of maize silage is, however, given to dairy cattle, while 45% is given to beef cattle. Maize silage is mainly produced on the farms where beef production is carried out. In Belgium, maize silage for dairy production is not exclusively reserved as a basic feed for winter rations. Supplementing dairy cattle at pasture with maize silage, especially in dry summer seasons, is common.
For non-ruminants, high moisture maize grain and crushed maize ears are given to fattening pigs and sows, while maize silage is given to sows. In 1975, about 5 000 ha of milled high moisture maize grain was given to fattening pigs and sows, while 300 ha provided crushed ears for fattening pigs. Only restricted amounts of maize silage are given to sows.
VARIETIES GROWN AND CONSERVATION METHODS
Table 2 presents a survey of the different varieties grown in Belgium in 1975 and 1976. For 1976, the data are based on the quantities of seed sold.
The varieties shown in Table 2 have been tested during the last 3 years for precocity and resistance against lodging (on a scale of 1 to 9) by NDALTP Brussels (1976). All varieties tested are registered on the Belgische Nationale Rassencatalogus (1975) except for the simple hybrid Anjou 196 which is registered on the Europese Rassenlijst (1976) and has not been tested.
As shown in Table 2, the LG, Primeur, Anjou group will constitute more than 80% of the land area in 1976.
For maize destined for grain production or to be harvested as crushed ears, LG7 was the most preferred variety. High kernel yield, precocity and good resistance against lodging will determine the choice of variety.
For maize destined for ensiling, climatic factors and soil conditions must be taken into account. In the coastal regions,
170 attention is particularly paid to resistance against lodging, whilst on the more dry and warm Campine north east regions, resistance to maize smut fungi (Ustilago maydis) is an important factor. Although no variety is resistant, we must distinguish between sensitive varieties such as Anjou 210, and especially Inra 258, and less sensitive varieties such as LG11 and Dekalb 202.
TABLE 2 VARIETIES OF MAIZE GROWN IN 1975 AND 1976
Variety 1975
ha
LG7 27 LG11 9 Cargill Primeur 170 8 Anjou 210 5 Inra 258 20 Anjou 196 But 234 Fronica
Others* 1
000 500
600
790
270
2 50
000
% of total area
37.3 13.1
11.9
8
28
0.4
1.3
1976
ha
29 12
11
8
7
5 3 3
1
000 000
000
000
000
000 750 500
000
% of total area
36.1 15
13.7
10
8.7
6.2 4.7 4.4
1.2
Precocity
8 6
7.4
5.4
4.6
early 5.8 5.7
Character!
Resistance against lodging
8.7 8.7
8.4
8.4
8.7
8.3 8.1
sties
Dry matter yield
++ +++
++
++
+
++ ++ +++
* Maris Carmine, Inra 200, Dekalb 202, Leopard, Capella, Prestor.
On the small mixed farms of the Flanders area, the system of growing Italian rye-grass or winter rye before maize is frequently applied.
Forage maize is mainly conserved in clamp or trench silos, after chopping in the field to a maximum length of 2 cm, and without additive. The Belgian farmer has been allowed to use NPN sources such as urea and biuret for silage making since February 1974. Price conditions of protein concentrates vs non-protein nitrogen are determining the use of these NPN sources.
171
In 1975 only about 20 airtight silos (Harvestore type) of 500 m were used for ensiling maize. About half were used for ensiling maize forage (14 ha χ 50 t/ha = 700 t/silo); the other half were destined to conserve high moisture maize grain (45 ha χ 6 t/ha = 270 t/silo). In total about 7 000 t of forage maize and about 2 700 t of high moisture maize grain were therefore ensiled in airtight silos. As mentioned before, only about 300 ha (15 000 t) compared with a total quantity of 3 300 000 t of maize silage are dehydrated and pelleted.
QUANTITIES OF MAIZE GRAIN IMPORTED
The direct import of maize from nonEEC countries decreased from c 700 000 t in 1969 to 350 000 t in 1973 (Table 3).
TABLE 3 TOTAL IMPORTATION OF GRAIN AND MAIZE INTO BELGIUM (1 000 t) *
Year
1969 1970 1971 1972 1973
Total importation
Total grain
3 115 4 043 3 866 3 927 4 278
Maize
1 139 1 362 1 504 1 490 1 451
Importation from the EEC
Total grain
1 626 2 252 2 272 3 030 3 372
Maize
450 560 826
1 084 1 107
* Mahieu (1976)
However, 188 000 t imported from nonEEC countries was supplied by the Netherlands in 1973. The importation of maize from nonEEC countries, therefore, amounted to c 540 000 t. Besides the Netherlands, France was a major supplier from within the EEC. There has evidently been, for all grains without exception, a great increase of importation from other countries within the Community.
BEEF PRODUCTION SYSTEMS
Maize forage has two important advantages compared with other
172 forages in an intensive beef production system, namely a reasonably constant digestibility, coupled with increasing dry matter intake with increasing stage of maturity. With other forages, however, harvested as hay or conserved as silage, a decline in digestibility and dry matter intake occurs with advancing maturity.
Beef production systems in Belgium with maize as the basic feed are shown in Table 4. There has been a strong tendency towards higher live weights at slaughter over the past few years. The high purchase prices of new-born calves and store cattle, together with better selling prices for heavier animals, of higher meat quality,are responsible for the increased slaughter weight. The production of young intensively fed bulls (baby-beef) with a market weight of 480 - 525 kg therefore remains rather limited.
In the category of fattening bulls, the production of animals with a live weight at slaughter of 525 - 575 kg in 15 - 18 months, is the most common system for larger farms in the middle and south of Belgium. This system is characterised by a period of moderate gain on pasture (4 months) after the initial rearing period. The finishing period starts at 200 - 250 kg live weight.
The production of fattening bulls with a market weight of 575 - 650 kg after 20 - 22 months is more usual on the small mixed farms of Flanders. It differs from the previous system in having a longer pasture period ( 6 - 7 months); the finishing period starts therefore only at 300 - 350 kg.
More details concerning beef production systems in Belgium with other categories of animals are reported by Buysse and Boucque" (1975) .
Fattening bulls in the three systems described, (Table 4) can be fed during the finishing period with either maize silage ad libitum, dehydrated maize pellets or high moisture maize grain.
As mentioned before, the use of high moisture maize grain conserved with propionic acid, or of dehydrated whole maize plant pellets, remains rather limited.
Maize is always supplemented with protein rich concentrates at a level of 0.75 or 1% of the live weight depending on the production system used (Table 4).
173 TABLE 4 BEEF PRODUCTION SYSTEMS WITH MAIZE AS THE BASIC FEED
Production system
1. Young bulls (baby-beef) (intensive system)
2.Fattening bulls (semi-intensive)
3. Fattening bulls (semi-intensive)
4. Young steers
Market weight (kg)
480-525
525-575
575-650
c 600
Age (months)
12-13
15-18
20-22
c 24
Basic feed
1.
1. 2.
3.
1. 2.
3.
1.
Rearing period: Maize silage Maize pellets High moisture maize grain Rearing period Pasture period (4 mos.) From 200 - 250 kg Maize silage Maize pellets Hioh moisture maize grain Rearing period Pasture period (6-7 mos.) From 300-350 kg: Maize silage Maize pellets High moisture maize grain Wintering ration: all types of silage incl. maize silage
Concentrates
1% LW (protein rich) NPN-sources
0.75 or 1% LW (protein-rich) NPN-sources
0.75% LW (protein-r ich) NPN-sources
1 kg/day (protein-rich)
In the two semi-intensive systems with fattening bulls, the concentrate can also be limited to 2 kg per day, but consequently maize silage is supplemented with 2 - 4 kg dried sugar beet pulp pellets per day.
The concentrate can also be replaced by urea-N. Ordinarily, 1% of a commercial mixture composed of 50% urea and 50% minerals is added to the maize forage at ensiling.
Maize choppers are sometimes equipped with an apparatus to add the product during chopping in the field.
In 1975 c 1 000 t r.umipec (commercial mixture of 50% urea
174
and 50% minerals) was used by farmers to enrich c 2 000 ha maize silage for its deficiencies of nitrogen and minerals.
The performance of fattening bulls fed on maize silage, dehydrated whole maize plant pellets or high moisture maize grain is presented in Table 5.
TABLE 5
PERFORMANCE OF BULLS FED WITH MAIZE SILAGE, DEHYDRATED WHOLE PLANT MAIZE PELLETS OR HIGH MOISTURE MAIZE GRAIN
Basic feed
Concentrate level (proteinrich)(%LW)
Number of bulls Initial weight (kg) Final weight (kg) Daily gain (g) Daily feed intake (kg) Concentrate Maize silage Maize pellets High moisture maize
(55% DM)
Feed conversion (kg) Concentrate (7.5 BF*) Maize silage (0.7 BF) Maize pellets (4.75 BF) High moisture maize
(4 BF)
Feed cost per kg gain (BF)
Maize
0.75
• 62 289 572
1 094
3.1 19.3
2.8 17.6
33.3
silage
1
78 278 566
1 183
4.1 17.7
3.4 14.9
36.1
Maize pellets
1
72 278 567
1 184
4.1
5.4
3.45
4.6
47.7
High moisture maize
1
26 277 571
1 408
3.8
7.1
2.7
5.1
40.7
♦Belgian Francs Beef p r o d u c t i o n r e s u l t s w i t h maize as t h e b a s i c feed a r e
p r e s e n t e d i n more d e t a i l by Poucqué e t a l . ( 1 9 7 6 ) .
175
REFERENCES
Boucqué, Ch. V., Cottyn, B.G. and Buysse,· F.Χ. 1976. Maize silage without or with NPN, dehydrated wholecrop maize pellets or high moisture corn for finishing bulls. In: J.C. Tayler and J.M. Wilkinson (Editors) Maize as a basic feed for beef production. Animal Feed Science and Technology
Buysse, F.X. and Boucqué, Ch. V. 1975. Present and future beef production systems in Belgium. In: J.C. Tayler and J.M. Wilkinson (Editors) Improving the nutritional efficiency of beef production. Commission of the European Communities, Luxembourg.
Gemeenschappelijke rassenlijst voor Landbouwgewassen. 1976. Tweede volledige uitgave. Publikatieblad van de Europese Gemeenschappen. 19° jaargang nr C65 20 maart 1976.
LEI Statistieken 1975. Landbouw Economisch Instituut, Ministerie van Landbouw, Brussel.
Mahieu, A. 1976. In en uitvoer van plantaardige produkten. Landbouw
tijdschrift 29:33. Nationale Rassencatalogus voor Landbouwgewassen. 1975. Ministerie van
Landbouw, Brussel. NDALTP. 1976 Nationale Dienst voor Afzet van Land en Tuinbouwprodukten.
Ministerie van Landbouw, Brussel NIS. 1975. Landbouwstatistieken. Nationaal Instituut voor de Statistiek.
Ministerie van Economische Zaken, Brussel.
Animal Feed Science and Technology, 1(1976) 177181 tlscvier Scientific Publishing Company, Amsterdam Printed in The Netherlands
USE OF MAIZE FOR LIVESTOCK FEEDING IN THE NETHERLANDS 177
F. de BOER Institute for Animal Feeding and Nutrition Research "HOORN" Postbus 67, Keern 33, NL Hoorn, The Netherlands.
HISTORY AND AREA
The production of maize in the Netherlands started about 130 years ago. However, results were inconsistent and so the area cropped with maize remained small. A new interest grew some years before and during World War 2. A total area of about 4 500 ha was sown with maize at that time. The main purpose was the production of maize as a grain crop, but occasionally, because of frequently poor harvest conditions, farmers had to make maize silage. Favourable maizegrain prices pushed the area up to about 14 000 ha in 1952. Subsequently a substantial decline in grain prices resulted in the area shrinking down very quickly to about 4 500 ha and at the same time the switch from grain to maize silage began. New strains of maize, modern harvesting and ensiling equipment, more efficient cropping systems caused a remarkable increase in the area sown to maize in the Netherlands from about 1970 until now as is shown in Table 1.
TABLE 1 AREA (ha) OF MAIZE IN THE NETHERLANDS
For maize silage For grain Area for arable crops χ 1 000 ha Maize area as %
1969
4 200 60
720
of arable crops 0.6
1970
6 40O 1 000
686
1
1971
13 200 2 300
679
2
1972
29 5O0 3 800
685
*
| 1973 1
¡50 O0O I 2 900 i i 675
! 8
J.974
73 500 1 900
675
11
1975
77 500 1 400
675
12
As a result of this spectacular change maize now covers about 12% of the area used for arable crops in the Netherlands and ranks in fourth place after potatoes, wheat and sugarbeet.
178 About 90% of the total maize area is concentrated in the
sandy soil region of the country (mainly in the south and east). Table 1 clearly shows that maize grain production in the Netherlands ranks far behind the maize silage production, although the increase in grain production has been relatively greater.
VARIETIES AND HARVESTING METHODS
The most popular variety of maize cultivated in the Netherlands at the moment is LG 11 (1975: 53%) with Capella (1975: 36%) in the second place (Capella was called formerly Caldera 535). Some years ago the variety called Leopard was fairly important.
Only a small percentage of the maize crop is fed fresh, mainly in emergency situations. The big bulk is harvested and made into silage in the last half of September and the first half of October. There has been a slight interest some years ago in artificial drying of fresh and ensiled maize, but because of excessively high production costs it did not gain popularity.
Fresh maize is cut at the stage of maturity, characterised by the grain being from dough to hard dough stage of ripeness. At that point the most favourable combination of factors, such as dry matter output, content of feed energy (SE), average digestibility, suitability for the ensiling process and for maximum feed intake by cattle, appears to be available. Farmers always try very hard to have maize ensiled with a dry matter content of at least 25%. Of course 30% or higher is preferable. However, climatic conditions sometimes prevent these levels being attained, resulting in a substantial loss of effluent, and consequently loss of feed. Feedtables from the Dutch Bureau for Livestock Feeding show data for the feeding value of maize silage, (Table 2).
TABLE 2 FEEDING VALUE OF DUTCH MAIZE SILAGE
DM Nutrients in dry matter (g/kg) (g/kg) SE dep Ca Ρ Mg Na
Maize silage 260 600 55 2.5 2.5 1.3 0.2
179 UTILISATION OF MAIZE
Most of the maize silage produced in the Netherlands is fed to dairy cattle. From a rough calculation one may conclude that 90 - 95% of the annual production of maize silage is fed to dairy cows and the remainder to fattening cattle, mainly young bulls.
The gradual, but continual, increase in the size of dairy farms in our country has led to a discrepancy between herd-size and roughage-producing area on the farm. High application rates of fertilisers, very efficient pasture-utilisation etc. allowed many dairy farmers to raise the number of dairy cows per ha up to about 3. Having attained that stage the roughage-part in the winter ration approaches the minimum.
This has led quite a number of (mainly small) farmers on mixed farms (pasture and arable crops) to increase the acreage of maize at the cost of grain crops such as rye and oats. In fact, the area of these two grains, comprising about 150 000 ha in 1969/70 shrunk down to about 50 000 ha in 1974.
Secondly quite a number of farmers have specialised their animal production in such a way (pigs, poultry) that crops from their farm area are not needed for their own enterprise.
A third group of farmers stopped farming (with financial support of the government) but made their agricultural area available for maize cropping.
Especially these two groups of "farmers" sell their maize crop on contract to dairy farmers with large herds of cattle.
There has been a substitution of pasture by maize, but this is restricted to those lots that are located at considerable distance from the farm and its main land-concentration. Pasturing is in such circumstances technically not feasible and so it was decided quite often to grow maize on that area. Moreover, it requires only a minimal amount of farm-labour because in general a contractor will handle the crop completely from seeding through to harvesting.
As mentioned already, maize growing for grain production is relatively unimportant in the Netherlands. Still the amount of maize-grain fed in animal husbandry in our country is large. It is by far the most important grain in the compound feed industry, which produces over 10 500 000 t per year. Maize comprises about
180
23% of this bulk, viz. 2 500 000 t. Assuming an average yield of maize grain of 5 t per ha, this means that the Netherlands are utilising the maize output from 500 000 ha elsewhere (mainly in USA and France) to feed its poultry, pigs and cattle.
FEEDING
Dairy cattle need a fairly high content of protein in relation to energy during lactation. If energy is expressed in starch equivalent the optimal SE/dcp ratio should be about 5 : 1 . In maize silage this ratio is extremely high (12 : 1) requiring special measures in dairy cattle feeding. Therefore the feeding of maize silage as the sole basal diet with concentrates to dry cows, and cows giving less than 10 kg milk per day, is avoided. In these conditions (existing only on a relatively small number of farms) part of the roughage ration has to be grass hay and/or grass silage. These roughages, containing a relatively high protein content, alleviate the extreme energy-protein ratio in the ration and prevent the cows from putting on too much fat. For cows producing more milk, a combination hay/grass silage and maize silage is strongly advised, for the same reasons, and to allow the farmer to use only one type of compound concentrate, with dcp content of about 18%.
In rations for dairy cattle, maize silage is generally fed together with at least 2 kg dry matter from hay or (wilted) grass silage, to prevent low milk fat contents and feed refusals.
Young fattening bulls are increasingly being fed on maize silage as the most important part of their ration after 3 months of age. In general it is still a combination of grass hay and/or grass silage with maize silage, supplied with increasing amounts of a compound feed as the end of the fattening period approaches. However, utilisation of maize silage as the only feed for young fattening bulls is increasing. About 25kg maize silage and 2-4 kg concentrates, rising during fattening can serve as an average example of a ration which enables young bulls to gain about 1 100 g daily. In fact the specialised bull fattening units are based on maize growing and maize silage feeding. The bulls are slaughtered at about 15 - 16 months of age.
181 Utilisation of maize silage as a roughage for breeding sows
is gaining more interest nowadays in the Netherlands. Large sow units combine two advantages in this way: they economise on the purchase of concentrates and they alleviate their problems of pig manure production by fertilising the maize crop heavily with the manure. In this way large-scale pig farming can, at least, partly avoid the risk of being a potential polluter.
The necessity to supplement maize, because of its very low content of protein (and mineral), with protein-rich concentrates has led to much research work to find alternative sources of supplementary Ν for ruminants. So urea is fed occasionally in the Netherlands, especially when protein prices are high, as they were a few years ago. If it is applied it will be fed mainly to fattening young bulls, while protein-rich conserved feeds from pasture will remain important in dairy cattle rations.
Some experience has been gathered by applying a urea-mineral mixture, added mechanically to the maize while being harvested (about 1 000 ha). The percentage of urea added was about 0.5% per kg fresh maize. The results obtained in feeding this type of "high-N" maize silage were promising. However, recent research results in fattening trials suggest that protein requirements of young fattening bulls are substantially lower than was assumed until now. So the need for urea in the Netherlands seems to be smaller than that indicated by the former feeding standards.
Animal Feed Science and Technology. HÌ916) 183-186 183 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
MAIZE AS A FORAGE CROP IN DENMARK
KR. G. MØLLE Statens Forsøgsstation, Ødum, DK 8370 Hadsten, Denmark
ABSTRACT
Owing to climatic conditions, grass, legumes and root crops have for years constituted the basic forage plants in Denmark. Maize growing has often been attempted, but even now, after the development of several new cultivars, crops of silage maize can only be grown satisfactorily in some southern and eastern parts of the country.
INTRODUCTION
For a very long time, legumes, grass and different root crops have been grown and utilised as basic forage plants. In the course of the last 3 to 4 decades, fodder sugar beet has become the most important forage root crop.
These forage crops are rather well suited to the climatic conditions of Denmark. In order to examine the possibilities of other forage plants, The Danish State Research Institute in Plant and Soil Sciences has carried out trials with new cultivars of maize. The extension service working with research organisations also has, at intervals, done experimental work to elucidate whether or not maize could be grown successfully in Denmark. Farmers, too, have occasionally tried to grow maize.
Since about 1970 the interest in growing maize has been increasing, and the experimental work has correspondingly intensified.
MAIZE AREA
The acreage of maize in Denmark is negligible. Estimated on the base of seed sold, about 1 500 ha of silage maize may be grown in 1976. For comparison, data are given in Table 1 of the areas of other crops in Denmark.
184
TABLE 1 CROPS GROWN IN DENMARK
Crop
Barley Other cereals and pulses Root crops Potatoes Grass and green fodder in rotation Permanent pasture Seeds, other crops and fallow
Total arable area of farms (1974)
1 000 ha
1 437 303 248 33
469 277 138
2 905
Percent of total
49 10 9 1 16 IO 5
100
Source: Danmarks Statistik, 1975.
In years with an exceptionally mild and favourable growth season, it has been possible to obtain nearly ripe maize in the south-eastern part of Denmark. However, if maize has a real chance in this country, only maize grown for silage or green fodder could reasonably be taken into consideration.
YIELD OF MAIZE
At present the Danish State Research Institute in Plant and Soil Science annually tests 15 - 20 cultivars of maize and 4 cultivare were registered in the Danish List of Cultivars of Agricultural Crops 1975. Table 2 shows average results from trials carried out over the period 1972/74.
The variations in yield from year to year and between localities demonstrate that the northern limit for successful production of silo maize passes through Denmark.
By comparison, the normal dry matter yield of grass adequately fertilised with nitrogen for the years 1972 - 74 averaged 12.8 and 10.6 t at Rønhave and Ødum respectively.
As a whole, the yield levels shown in Table 2 are not unequivocally higher than the yield level obtained in trials carried out with other maize cultivars 15 - 20 years ago, apart from the locality Ødum where the climate is cooler than that of Rønhave.
18S TABLE 2 YIELD OF DRY MATTER (t/ha)
Year or locality
1972 1973 1974 Average: 1972 - 74 Rønhave (Southern Jutland) Ødum (Eastern Jutland)
Cultivar
Anjou 210
9.4 12.2 8.0 9.8 11.4 7.9
LG 7
9.3 12.6 8.0 10.0 11.5 8.1
LG 11
9.9 12.9 9.1 10.6 12.1 8.5
CapeIle
9.4 13.4 8.4 10.4 12.3 8.4
Reference: Pedersen, 1975
MAIZE VARIETIES
Until now the goal for attempting maize growing has been to achieve a crop with a dry matter content of about 30% in order to produce silage of high quality and without effluent loss. This dry matter content presupposes a rather well developed ear, and the goal is seldom reached. Very often the dry matter content of the whole crop lies between 20% and 25%.
Of the cultivars mentioned in Table 2, Anjou 210 and LG 11 have received most attention, but this year the cultivar Fronica has been especially in demand.
As mentioned, maize has until now been regarded as a silage crop. However, trials have been initiated to elucidate whether maize could be advantageously grown and utilised as a stall-fed forage crop from early August. For this purpose the dry matter level would be relatively unimportant and the most important question is whether or not the crop can attain a reasonably high yield of dry matter, the quality of which, when harvested day by day over a period of 1 to 2 months, is high and uniform. It is an open question whether there is likely to be a demand for maize for silage and maize for stall-feeding in the future. If there is, then two types of maize will be required in Denmark, a type giving a relatively well developed ear, and a type producing a high yield of vegetative mass.
186
IMPORTATION OF MAIZE
The main proportion of imported maize comes from North America. The yearly imported quantities are small, and chiefly used in feed mixtures for chickens. The total amounts of cereals and of maize used for livestock feeding are illustrated in Table 3.
TABLE 3 CEREALS GIVEN TO LIVESTOCK, 1964 1974
Fiveyear period
1964/65 1968/69, 1969/70 1973/74,
average average
1 000 t
Cereals, total
5 393 5 801
Maize
170 232
Maize as percent of
total
3.1 4.0
Source: Danmarks Statistik, 196875.
REFERENCES
Pedersen, Κ.E., 1975. Sorter af majs til grr/nhi/st. 1237. meddelelse fra Statens Forsøgsvirksomhed i Plantekultur.
Danmarks Statistik, 196875.
Animal Feed Science and Technology, 1 (1976) 187-193 187 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
PROSPECTS OF GROWING MAIZE IN FINLAND
S. PULLI, E. POUTIAINEN and LIISA SYRJALA Department of Animal Husbandry, University of Helsinki, 00710 - Helsinki 71, Finland.
Maize has been studied in Finland during several periods. Virtanen (1938) worked with maize in the 1930's. His experience was positive and encouraging. At the Agricultural Research Centre in Tikkurila near Helsinki, results obtained in the 1950's were disappointing, owing to drought and early autumn frosts. In 1962, rainy and cold weather did not favour the growth of maize and research workers concluded that maize was not a suitable crop for Finnish growing conditions (Yllo, 1962).
Maize research received a new impetus from the spectacular results of Mr. G. Brüninghaus on his private farm in South West Finland. In 1974 the Finnish Maize Committee was founded to sponsor maize research in Finland once more. The new start of maize research was also spurred on by the new, high yielding varieties and new cultivation techniques developed in maize growing countries.
At the moment, the cultivated area occupied by maize in Finland is tiny. Maize cultivation is mostly confined to South West Finland and is practised on beef cattle farms. The cultivated area is 40 - 50 ha.
MAIZE AND SOLAR RADIATION IN FINLAND
The amount of available radiation is very important for the growth of maize. At the beginning and in the middle of the summer, the maximum value of the light intensity in Southern Finland is about 100 000 lux and in August is still 85 000 lux. These values show that the amount of light is not the limiting factor for the growth of maize.
TEMPERATURE CONDITIONS IN FINLAND
The factor limiting the growth of plants in Finland is
temperature rather than light. Eritish research results show that forage maize needs 728 accumulated degrees Centigrade to give economic returns,· this figure being the number of degrees above 10 C aggregated over the growing seasons. Grain maize needs an average of 762 accumulated degrees over the same period to produce mature grain at 40% moisture. These values are reached in only a few parts of Finland, and then not in every year. For instance, the 197 4 - 75 average for the accumulated degrees from May to September in Tikkurila were 594 C. However, in Finland the long summer days can compensate for the low temperature sum. Maize is supposed to require about 900 hours of light for matured grain, and we have 1200 -1300 light hours available during the growing season.
In Southern Finland, the growing season is 175 - 180 days long. The mean temperature of the whole growing season is 12.6 C. The mean temperature from June to August is 15.7 C, enough for the succesful growth of maize. The most critical factors are the spring and autumn frosts. The spring frost can be avoided if seeding is delayed until May 15 to 25. August frosts are very rare, but the occurrence of frost in September is 20 - 30%.
THE WATER REQUIREMENTS OF MAIZE
The most severely limiting factor for maize growth in Finland is lack of water during the early summer. The results of various studies show that 450 litres of water are needed for every 1 kg of dry matter produced. In the United States, for instance, this corresponds to 400 - 625 mm rainfall per month. The lower mean temperatures in Finland cause lower water requirements here. The objective, however, is 100 mm rainfall per month, which is not achieved in Finland. In Tikkurila, for instance, the average rainfall for 1971 - 74 during the growing season was 272 mm and the distribution of the rainfall was not the best possible.
In Finland, the usual 25 - 50 mm of rain during the flowering period of maize is inadequate, since over this period the plant uses almost half of the water required for its entire growth and development. The dry period in the
TABLE 1 MAIZE VARIETIES IN SOUTHERN FINLAND IN 1975 (280 VARIETIES IN THE TRIALS)
Variety
Limagrain 775007 672508 LG 5
" LG 11 LG 7
Inra 176 Cargil 170 Princus
Height (cm)
260 275 265 250 250 205 205
2 Plants/m
6.8 6.6 7.4 6.5 6.5 4.0 4.0
DM (%)
26.4 28.0 27.4 25.5 27.2 26.3 23.3
Whole crop DM (kg/ha)
10 041 11 026 11 485 11 419 10 209 5 780 8 657
Matured grain yield (kg/ha; 15% moisture)
4828 4955 5550 5580 4660 3280 3930
Protein (% of DM)
Average of seven varieties
Whole plant
8.4
Leaves and stalk
7.8
Whole ear
9.4
Grain
11.3
190 early summer in Finland means that maize must be irrigated.
PRELIMINARY RESULTS WITH MAIZE AND SORGHUM
The Finnish Maize Committee conducted preliminary trials with sweet corn and sorghum in 1974. In 1975, the trials were broadened to include maize, sweet corn and sorghum. The main part of the trials was run in Viurila, South West Finland, where 280 maize varieties, 30 sweet corn varieties and 14 sorghum varieties were grown and several experiments made to determine the appropriate management techniques. Maize trials
In Viurila, 40 varieties out of 280 produced completely matured seed in 1975. The year was extremely dry but a little warmer than usual. In late May, the crop experienced a rare -8 C frost. The autumn was warm and long, and favoured the growth of maize until the beginning of October. In Table 1 results for some of the best varieties in the trial are presented. In the preliminary trials, the French varieties appear to be best adapted to our growing conditions, although some Hungarian, Yugoslavian and Russian varieties are also promising. However,Dutch and British varieties seem to have difficulties in adapting to our continental growing conditions. Sweet corn for silage
Sweet corn has a relatively short growing time, and under our long day conditions it seems quite able to produce not only a good ear yield, but also a good stalk and leaf yield for silage. In Table 2, the results of sweet corn trials are shown for 1974 - 75. Varieties such as North Star and Spring Gold with a long vegetative phase have a relatively high silage dry matter yield and a low matured ear yield. Golden Beauty seems to have both yield components in satisfactory measure. Also the protein yield of sweet corn silage has considerable feeding value. Sorghum varieties in the trials
Sorghum has been tested during 1974 - 75. The preliminary results show that most of the varieties tested have a good dry matter yielding ability. Although the protein content of all the varieties is relatively low, the protein yield per unit
191
area is high, because the dry matter yields are high. The sorghum-sudan hybrid Grazer shows the best ability to grow in Finland (Table 3 ) . Beefbuilder is clearly too late under our growing conditions. Sorghum cannot produce matured seed in Finland.
TABLE 2 SWEET CORN VARIETIES IN 1974-75 IN SOUTHERN FINLAND
Variety
Buttervee Seneca - 60 Golden Beauty Sunnyvee Spring Gold Early Alberta North Star
Matured ear yield (kg/ha)
7 974 7 717 7 547 6 943 5 127 3 220 3 298
Matured ears (%)
77.7 89.6 69.4 86.4 56.8 49.1 42.1
Stalk and leaves DM (kg/ha)
4 70O 5 490 6 631 4 545 7 007 5 670 6 886
DM (%)
16.9 15.7 17.8 17.1 19.0 17.0 17.0
Protein (% DM)
11.9 12.1 12.9 12.3 11.7 11.8 12.1
TABLE 3 SORGHUM VARIETIES IN 1974-75 IN SOUTHERN FINLAND
Variety
Beefbuilder
Grazer
Astro
Seeding rate (kg/ha)
20 30 40 20 30 40 20 30 40
DM yield (kg/ha)
9 600 10 640 11 850 12 440 12 890 14 850 10 540 11 830 12 370
DM (%)
19.1 19.8 20.6 20.8 21.1 22.1 22.5 22.6 22.6
Protein (% DM)
11.0 10.6 9.8 10.1 9.9 8.7 9.6 9.6 10.0
192 MAIZE SILAGE FEEDING TRIAL
A preliminary feeding trial in farm conditions was arranged in 1976. It lasted two months and consisted of 60 beef animals, age 4.5 - 5.5 months at the beginning of the trial. The growth rate of the Ayrshire bulls before the trial was 700 g per day. Animals received maize silage ad libitum and an additional amount of concentrates containing 1.5 feed units with 218 g of digestible crude protein per feed unit. Dry hay was given at the rate of 0.2 FU per day. During the first feeding month, the 60 animals gained at an average rate of about 490 g per day and during the second month at about 650 g per day (Table 4) The average growth rate per animal during the whole test period was about 570 g per day. This relatively low value for the daily growth rate can be explained by the cold weather during the test period, as the animals were kept in a barn without walls. The other reason was the low proportion of ears in the silage dry matter caused by too dense a population and a relatively late seeding time.
TABLE 4 MAIZE SILAGE FEEDING TRIAL
Weight class
- 120 kg 121 - 140 kg 141 - 160 kg 161 - kg
Number of animals
14 22 14 10 60
Daily growth rate (g/day/animal) Dec 30 - Jan 30
431 434 566 597
Ave. 491
Jan 31 - March 1
578 651 655 723 647
Ave.
504 539 612 631 568
CONCLUSION
Maize and sorghum are sub-tropical C-4 plants with a high dry matter yielding ability. Maize is relatively well adapted to southern and central Europe. In preliminary tests in Finland, from 1974 -75, the results have been successful and
193
encouraging. Maize for silage can be grown in Southern Finland in relative safety in years free from August frost. There is a need for vigorous maize varieties adapted to more continental growing conditions. Sorghum has produced high dry matter yields and shown a good ability to utilise our growing season. If the spring start of the growth of maize and sorghum could be hastened by irrigation and other management practices, these species would produce higher dry matter and FU yields than other grasses and with relatively high security.
REFERENCES
Virtanen, A.I. 1938. Kokemuksia maissin ja maissi-peluskin viljelyksestä maassamme. Karjatalous: 8
Y11Ö, L. 1962. Maissin viljelykokeista Suomessa. Maatalous ja koetoiminta XVI: 101 - 110.
FURTHER INFORMATION MAY BE OBTAINED FROM:
Leonard, W.H. and Martin, J.H. 1963. Cereal crops. McMillan Company. New York, USA.
Owen, F.C. 1967. Factors affecting nutritive value of corn and sorghum silage. Journal of Dairy Science 50: 404 - 416.
Thomson, A.J. and Rogers, H.H. 1968. Yield and quality components in maize grown for silage. Journal of Agricultural Science, Cambridge 71: 393 - 403.
Voldeng, H.D. 1971. Factors affecting the growth of Zea mays. L.D. Phil. Thesis. Oxford University, England.
Animal Feed Science and Technology, 1(1976) 195-198 195 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
THE CURRENT SITUATION REGARDING THE USE OF MAIZE IN IRELAND
F.J. HARTE The Agricultural Institute, Grange, Dunsany, Co. Meath, Ireland
ABSTRACT
In Ireland, maize growing on a commercial scale started in 1970 though there were various attempts to grow it experimentally before that time. The area used for maize production rose to a maximum of 1 200 hectares in 1973 but has now apparently stabilised at approximately 400 hectares. Low temperatures have militated against consistent yields and it is felt that most of the country is unsuitable for growing the present varieties of maize. Maize, therefore, will not make any worthwhile contribution to cattle production in Ireland unless a variety can be found that will grow at lower temperatures (in May and September) than those now available. This is a challenge to the plant breeders.
AREA SOWN
The area of maize grown in Ireland is now approximately 400 ha per year and maize growing only started on a commercial scale in 1970. There were 1 200 hectares in 1972 and the decline in area seems to have been due mainly to the failure to get consistently good production results each year. The total area of forage crops is approximately one million ha while the area under grain crops is 240 000 ha. The total land area under crops and pasture is 4.85 million ha and the total cow population (dairy and beef) at present is approximately 2 million. I list cow numbers because they are the basis of our cattle production, and since we are capable of producing maize silage only, it must be utilised by ruminants.
Our Institute started a comprehensive maize programme in 1971 which is now nearing completion (Neenan, 1976). Over 40 varieties have been examined at our Research Centre at Oakpark, and all of them are sensitive to early and late season low temperatures. About 50% of the commercial maize grown is Cargill
196 Primeria 170, 40% is from the varieties Anjou 210 and LG 11, and 10% is Caldera 535. However, maize varieties used are often influenced by commercial pressures particularly when the level of interest in the crop is not high. It was also found we needed higher plant densities than those recommended in countries with warmer climates.
YIELDS
The yield has varied very much with season from 6.0 to 12.5 t DM/ha. The crictical point in degree days appears to be 550, and as an indication of our varying temperature, the degree days figure for 1972 was 527, while last year it was well above 800. It is interesting to note that in the growing season, the highest temperature in Ireland is equal to the lowest temperature in Holland, where we know there has been a great expansion in maize production. In Ireland, there is a 10% chance of frost occurring in May and again in early October.
MAIZE FOR SILAGE
The minimum dry matter concentration for ensiling maize is 20%. In Ireland, maize increases in DM content about 1% in every 10 days from September onwards but maximum dry matter production is achieved by September. No maize is grown to maturity. Harvesting can be a problem in late autumn owing to wet soil conditions. In good years, the ear contributes 40 -50% to total DM. There always has been, as might be expected, a close relationship between DM content of the plant and total DM production in any one year.
BIRD PROBLEM
It should be mentioned that birds, mainly rooks (Corvus frugilegus) are a great problem at sowing time, and of course if the seed is taken by birds, the land cannot be used for other crops that season because of the type of weed control used for the maize crop. No really effective bird control system has been devised.
197 FEEDING EXPERIMENTS
Maize silage has been given almost exclusively to beef cattle. Feeding experiments have been carried out by our Institute to investigate
a) the performance of cattle on maize silage, b) the effects of adding different sources of nitrogen, c) the relative value of maize and grass silages. The mineral content, particularly sodium, is sub-normal
and supplementation is needed. Supplementation with a protein source is necessary and here soyabean meal gave the best results.
When grass silage and maize silage were compared (and it will be appreciated that it is difficult to make a direct comparison), the results shown in Table 1 were obtained.
TABLE 1 COMPOSITION OF MAIZE AND GRASS SILAGE, AND PERFORMANCE OF CATTLE
Silage
Maize Grass
Composition Crude DMD
protein (%) (%)
8.8 69.0 10.3 77.1
DM Intake (kg/day)
8.23 8.88
Performance Average
dally gain (kg)
0.66 0.84
PRESENT RESEARCH AND THE FUTURE OF MAIZE
With the exception of a very small area on the south and south west coasts, the climate in Ireland is not suitable to ensure satisfactory production each year from maize. The situation could readily change if a maize variety were produced which would grow satisfactorily at 2°C lower (i.e. 8°C) than is at present available. It is estimated that maize would need to be consistently capable of producing 12 t DM/ha annually to ensure its competitiveness with grass and fodder beet. Further research on production, and feeding experiments on maize are now suspended until a suitable variety for our climate becomes available.
198
REFERENCE
Neenan, M. (ed) 1976. Fodder Maize, A Status Report, Agricultural Institute, Dublin, Ireland.
Animal Feed Science and Technology, UW b) 199-214 199 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
THE USE OF MAIZE FOR LIVESTOCK FEEDING IN THE UNITED KINGDOM
J.B. KILKENNY Meat & Livestock Commission, Queensway House, Bletchley, Milton Keynes, Buckinghamshire, U.K.
ABSTRACT
The area of grain maize grown in Britain is insignificant at about 1 000 ha and, in fact, has declined slightly over recent years; there is unlikely to be much of an increase in this area in the foreseeable future. Conversely, the area grown for silage has increased by 700% since 1971 and is now around 27 000 ha. The area suitable for growing maize silage includes the south and east of England, much of the midlands and sheltered sites in Wales and the south west. Two thirds of the maize area is in the south east and east of England. The yield of energy per ha is 107% higher than for barley grain and there are approximately 1 million ha of barley in the south east and south west of England that could potentially be replaced by maize silage.
The average yield in Britain is about 10 t dry matter (DM) per ha (at a DM content of 24%) . The average farm area grown for maize silage is about 10 ha. A high proportion of the crop is harvested by contractors and the most popular varieties are LG11, Dekalb 202 and Caldera 535.
Most of the maize silage produced so far has been given to dairy cows, although the recent trend is for more to be given to beef cattle. Because of the small farm areas of maize, in many cases the maize silage has been fed in combination with other feeds. Even in mixed rations maize silage has significantly reduced the cost of feed per kg of gain compared with more traditional feeds.
Maize silage can be fitted into a whole range of beef systems in Britain. Much of the beef in Britain is produced from grass/cereal systems with cattle slaughtered between 18 months and 2 years of age, and the average concentrate requirement over the animal's life is about 0.9 tonnes, much of which is in the form of barley which could be replaced by maize silage. Maize silage could be given in the winter in combination
200 with grass silage or hay. Development work is required in this field to consider the implications of reducing the requirement for grass conservation on the overall grazing management system for beef cattle.
The most exciting prospects are, however, where maize silage is used as the main feed for indoor systems of beef production. The two most likely applications in Britain are a feedlot system starting with the reared dairy-bred calf (i.e. a replacement for barley beef) and the winter finishing of suckled calves and stores (i.e. a replacement for traditional feeding based on hay, straw and concentrates).
INTRODUCTION
In the UK, livestock account for 65 - 70% of the total value of agricultural output. Most farms with beef cattle and sheep have a fairly high degree of self sufficiency in feeding-stuffs, but dairy, pig and poultry production depend very heavily on purchased feeds. Since the 1960s there has been a substantial increase in the number of stock, and particularly, of beef cows (104%).
Grass and forage account for approximately 82% of ruminant feed. The proportion varies from 67% for dairy cows to over 90% for beef cows, store cattle and sheep.
Manufactured compound feeds represent about 55% of farmers' total usage of concentrates. The difference represents home grown cereals, mainly barley, which are retained for use on farms.
Of the 2\ million tonnes of grains imported into the UK for feeding,approximately 2 million tonnes are grain maize. In addition a further 800 000 tonnes of grain maize are imported for starch and glucose production and 700 000 tonnes for whisky distilling. Thus the growing of more grain maize in the UK would have a direct import saving role. The development of earlier varieties means that the south and east of England can be considered to be just inside the northern limit of the crop for grain. The area suitable for silage maize is, however, much wider.
201
Newcastle . . „
Grain and ground ear maize
\ ^ \ Silage maize
Silage maize if sheltered
■55" Ν
54' Ν
53 Ν
52 Ν
51 Ν Ashford
0 miles
Figure 1 Areas suitable for grain and silage maize in Britain Compiled by the Meteorological Office. Source: Wye College Maize Unit 1975
Maize Grower's Handbook
TABLE 1 AREA SOWN TO MAIZE IN ENGLAND AND WALES (ha)
Silage Grain
Total
Silage as % of total
1971
2 047 1 250
3 297
62
1972
3 559 2 137
5 695
62
1973
6 674 1 097
7 771
86
1974 .
15 948 1 057
17 005
94
1975
26 020 893
26 913
97
Source: Agricultural Statistics. Ministry of Agriculture, Fisheries and Food
202
AREA AND RELATIVE YIELD
The map shown in Figure 1 indicates areas suitable in Britain for grain, ground ear maize and silage maize.
Although the areas on the map are those likely to be the most successful sites, Ministry of Agriculture returns show that maize silage is grown in almost all counties in England. The breakdown of the silage area by regions is as follows:
South east 28% South west 14% Eastern 35% East midlands 5% West midlands 5% Yorkshire S Lancashire 8% Northern 3% Wales 2% Table 1 gives the total area sown to maize since 1971 (700%
increase). The figures clearly show that the expansion of the maize
area in the UK is entirely due to maize for silage. Despite the rapid expansion, maize as a forage crop is still
in its infancy in the UK. However, results obtained over the past 10 years encourage the belief that consistently high yields can be obtained over considerable areas in England. As the crop is extended into cooler areas the risks must increase and yields will be less than those obtained in southern parts of the country, though careful site selection can compensate for increase in latitude. Whether or not these lower yields of wetter material are acceptable will depend on the alternative feeds and their relative costs. Table 2 gives some details of average yields and costs of feeds in Britain.
The area sown to grain maize has declined after the exceptionally poor growing season in 1972 and is likely to be confined to the most favourable areas of south east England until earlier varieties become available. Ground ear maize and corn-cob mix are possible alternative methods of harvesting the crop in the areas suitable for grain maize production.
The bulk of the UK maize crop is grown for ruminant feeding. For most ruminant stock the yield of energy/ha is generally
TABLE 2 APPROXIMATE YIELD AND COSTS OF VARIOUS FEEDS IN THE UK0
Barley Swedes Turnips Grass silage (average quality) Hay (average quality) Dried grass Grass for grazing Maize silage Mineralised urea Extracted soya bean meal Decorticated groundnut cake Linseed cake Fishmeal
Yield (t/ha)
4.3 60.5 58.0
33.0
6.5 12.5
37. ld
44.0
--
---
Yield of DM (t/ha)
3.7 7.3 5.2
7.4
5.5 11.3
7.4 9.7
--
---
Yield of ME° (MJ/ha)
50 690 93 440 58 240
66 600
46 750 119 780
87 320 104 760
--
---
Costs Variable costs
1.0O 0.52 0.59
0.66
0.70 1.64
0.40 0.68
--
---
(E/1000 MJ ME) Costs of production
2.50 1.14 1.30
2.90
1.40 5.77
0.50 2.12
--
---
Market price
5.40 4.63 -
5.60 7.50
2.00e
-
--
---
Digestible crude protein
(kg/ha)
303.4 664.3 379.6
754.8
214.5 1 536.5
1 369.0 679.0
— -
---
Costs (£ Variable costs
0.17 0.07 0.15
0.06
0.15 0.11
0.03 0.10
--
---
per kg of protein) Costs of production
0.42 0.16 0.20
0.26
0.31 0.39
0.03 0.33
— -
1v— --
Market price
O.90 0.65 -
.
1.30 0.51
0.12 -
0.05
0.28
0.31 0.46 0.29
a Figures are averages for two years 1974 and 1975. Yields and costs of feeds based on MLC records plus published information from ADAS, Universities, MMB. b Metabolisable energy, a Variable cost plus fixed costs but excluding rent of land. d Based on the number of livestock unit grazing days in MLC Grassland Recording Scheme. e Cost of renting grassland.
204 the most important economic factor in a comparison of alternative feeds. It is for this reason that maize silage is increasing in popularity, since it produces 107% more energy per ha on average than barley grain, and 57% more than grass silage (Table 2). Additionally, the yield of energy as livestock feed per ha decreases as the proportion of the crop ensiled decreases (Fig.2).
αϊ en
a o
c"0/,v
>*/:
u 111 4J JJ 111
fi >. M
Ρ
riP
t i C Cl) 4J C O υ
CKOIINI) KAR ΜΛΙ7.Η 30 H.r. 40
1 I L_ I M N - C U I I MIX 41) 4.Ί
_ | L 4(1 4 5
_J l_
10 20
SKI'TKMHF.R 111 211
OCTOHF.K
Figure 2 Dry matter yields and relative maturity dates for different maize products. Source: Wye College Maize Unit 1975. Maize Grower's Handbook.
205 WHAT CROP DOES MAIZE SILAGE REPLACE?
This decision at the farm level can only be made after detailed planning of the whole farm system. Nevertheless the replacement of barley grain by maize silage has a significant effect on the true stocking requirements of livestock systems and profitability. The average 18 month beef animal consumes 760 kg of barley grain in its life time and thus requires approximately 0.2 ha of arable land per head in addition to the grassland stocking rate. The equivalent amount of energy could be produced by 0.08 ha of maize silage. Further comparisons between barley grain and maize silage costs and yields are given in Table 2, and a comparison between feedlot systems for beef production based on barley grain or maize silage is shown in Table 3. Such comparisons need, of course, to be treated with caution but it can be seen that only a modest yield of maize silage (4.2 t DM/ha) is required to 'break even' in terms of physical output with barley grain.
TABLE 3 DIFFERENCES BETWEEN MAIZE SILAGE AND BARLEY GRAIN IN A FEEDLOT SYSTEM OF PRODUCTION
Feed conversion ratio (kg DM/kg LWG) Age at slaughter (months) Crop yield (t DM/ha) Liveweight gain (kg/ha) Stocking rate (animals/ha at 410 kg slaughter weight)
Maize silage
5.7 14 9.7 1702
4.6
Barley grain
5.4* 12 3.7 685
1.9
MLC top third results
The choice between grass or maize silage is more complex. For any particular farm there will be advantages or disadvantages of growing one or the other. In areas of cooler temperatures and with no lack of rainfall, grass will be the normal choice, and in areas of higher temperature and where low rainfall restricts grass production, maize will be attractive. Undoubtedly, maize
206 is an easier crop to ensile and it is much less variable in quality than is grass silage. Good grass silage is as good as average maize silage but too few British farmers make good grass silage. Clearly there are areas where a combination of grass and maize for silage will be appropriate and indeed for some situations this will be a better solution than exclusively growing maize or grass for silage. In the case of beef cattle, however, the reduced requirements for grass silage in the winter can complicate grazing management. Most grass silage has more than sufficient protein for finishing beef cattle but is deficient in energy, (i.e. the opposite to maize silage which is low in protein but is a high energy feed).
Much of the increase in area of maize silage has been, and will tend to occur, in arable areas where the crop can also be used as an effective break crop in the arable rotation. There are approximately 1 million ha of barley in the south east and south west of England that could be used to grow maize silage.
The importance of yield has already been mentioned and the relationship between yield, stocking rate and liveweight gain per ha is shown in Table 4.
TABLE 4 THE EFFECT OF YIELD OF MAIZE SILAGE ON STOCKING RATE AND LIVEWEIGHT GAIN PEK HA AND ON COSTS OF PRODUCTION
Yield of maize silage (t DM/ha)
8 9 10 11 12 13
Liveweight (kq/ha)
FCRa 5.7 : 1
1403 1579 1754 1930 2105 2281
gain
6.7 : 1
1194 1343 1493 1642 1791 1940
Stocking rate animals/ha
5.7 : 1 6.7 : 1
4.5 3.9 5.1 4.3 5.7 4.8 6.2 5.3 6.8 5.8 7.4 6.3
Costs (E/1000 MJ ME)
Variable Cost of* costs production
0.83 2.57 0.74 2.28 0.66 2.06 0.61 1.87 0.56 1.71 j 0.51 1.58 !
a Feed conversion ratio b Variable costs plus fixed costs but excluding rent of land.
207 Yield is also important in relation to the unit costs of
feed. Table 2 shows the cost of maize silage at an average yield of 44 t/ha and Table 4 also shows the effect of different yields on the cost of maize silage. Maize silage is an expensive crop, and recent work has looked at ways of reducing the cost of production. An important development has been the use of slurry to replace inorganic fertilisers, which reduces the variable costs of growing the crop by about a quarter.
SILAGE MAKING IN BRITAIN
The average area grown for maize silage on British farms is about 10 ha. This represents a marked increase over the last five years as more producers have become committed to the crop. There is still a very wide range in the area grown on individual farms, ranging from small plots of less than 2 ha where farmers are 'experimenting' with the crop, to individual farmers who have been growing the crop for 10 years or so with areas in excess of 40 ha.
As digestibility remains constant for a long period (Figure 2) the crop is ideal for contract harvesting. A recent survey recorded that 40% of the surveyed crops were harvested by a contractor; the area of maize grown on these farms was less than half the area on farms where the farmer used his own machinery.
Nearly all the maize silage made in Britain is put into bunker type silos. In the ICI/MDA survey* about two thirds of all crops were ensiled in bunkers, and buckraking was the most common handling method. Although maize silage can be easily handled in or out of tower silos the dry matter content of much of the silage (Table 5) is too low to be suitable for towers because of the high quantity of effluent produced. This is in addition to considerations based on the relative costs of tower and bunker silos.
Table 5 gives details of average yields and composition of typical maize silage in Britain and some indication of the very wide variation in yields and composition is also given. Important reasons for the wide variation in yields are site, seed bed preparation, plant population and variety. *Survey of 166 farms carried out jointly by Imperial Chemical Industries Ltd. (ICI) and the Maize Development Association (MDA) in 1975.
208
TABLE 5 TYPICAL YIELDS AND COMPOSITION OF BRITISH MAIZE SILAGE
Yield, fresh weight (t/ha) Dry matter (%) Dry matter yield (t/ha) Digestible organic matter (% DM) Metabolisable energy (MJ/kg DM) Crude protein (% DM)
Average
40 24.0 9.7
68.0 10.8 9.0
Typical between
22 -20 -5.5 -
65.0 -9.9 -8 -
range farms
55 30* 14.0 72.0 11.8 11
* Large year to year variation, e.g. 1974 average 21.4%, 1975 27.3%
The varieties of forage maize recommended by the National Institute for Agricultural Botany (NIAB) are shown in Table 6. The most popular forage varieties are LG11 DeKalb 202 and Caldera 535.
Most of the maize silage produced to date in Britain has been given to dairy cows rather than beef cattle, although the trend indicates that a higher proportion is now being given to beef cattle. This is partly a reflection of the areas in which most of the maize silage has been grown until now and the relative profitability of beef and dairy production, particularly when capital investment is necessary.
MAIZE SILAGE FOR BEEF PRODUCTION IN BRITAIN
Most of the maize silage given to beef cattle up to date has been given in conjunction with other feeds. This reflects partly the need to establish confidence in the feed by individual farmers and also many of the farmers initially have grown only limited areas of maize silage in relation to their requirements for cattle feed.
The main nutrient deficiency in maize silage for beef cattle is that of protein. Alternative methods of protein supplementation of maize silage for beef cattle are available and there is scope for reducing the costs of the ration by using non-protein nitrogen (NPN). Protein supplementation of maize silage can be achieved in three ways:
TABLE 6 RECOMMENDED VARIETIES
Varieties"1"
*PS *S
Ρ G
G Ρ
0 Ρ G Ρ Ρ
G 0
Ρ G
0
Sprint Julia
Cistron LG 11
DeKalb 202 Campo
DeKalb 204 Kapio Anjou 210 Fronica Pioneer 131
Caldera 535 Anjou 196
Onyx 95 Orla 264
Austria 290 Mean
Origin
France Netherlands
Netherlands France
France Netherlands
France Germany France Netherlands Netherlands
Netherlands France
Netherlands Switzerland
Austria
OF
C] 9 0
FORAGE MAIZE
ass = very early ■ very late
9 9
8 8
7 7
6 6 6 6 6
5 5
4 4
3 -
(BASED ON DATA FROM TRIALS 1973 - 1975)
Dry matter at harvest (%)
28.4 28.4
27.1 26.6
26.4 26.3
25.4 25.3 24.7 24.7 24.7
24.4 24.2
23.2 23.0
23.4 -
Days to tasselling
83 83
87 90
87 88
90 89 87 89 89
89 86
90 90
92 -
Relative yield of dry matter
90 90
104 103
1O0 106
96 10O 10O 110 96
104 98
101 101
99 10O
(=11.6 t/ha)
Early vigour 9 = good 0 = poor
7 7
8 7
6 8
5 7 7 8 6
7 7
6 8
7 7
Resistance to lodging 9 = good 0 = poor
7 8
8 9
7 8
7 8 7 8 7
8 6
8 7
β 8
Height (cm)
175 174
186 182
188 189
179 188 186 185 177
190 191
188 193
204 186
+ Varieties classified for: General use G, Special use S, Provisional recommendation P, Becoming out-classed * Julia is recommended where a high dry matter content is especially important and Sprint is provisionally recommended for this purpose.
0.
210
a) addition of NPN at the time of ensiling b) addition of NPN at the time of feeding c) provision of a separate protein supplement, with or without NPN. There does not appear to be any difference in the efficiency
of protein usage by the animal between these three methods. A recent survey (ICI/MDA) showed that only 15% of crops had additives applied and most of these were applied after ensiling.
The advantage of adding NPN at the time of ensiling is that the maize becomes a complete feed and this simplifies the feeding system if only one type of ration is required. If the maize is to be given to different classes of stock with different protein requirements, then flexibility is lost. Either the protein in the maize is at the level required by the animals with the highest requirement for protein, in which case protein will be wasted by other classes of stock, or alternatively, the protein level is set at the requirement for the lowest level of protein and the silage has to be supplemented for those stock with more critical requirements and the advantage of a simple feeding system is lost.
A further point is that commercially available NPN products in Britain do not always provide the cheapest source of 'protein'. Prices per unit of protein vary markedly between different products and at different times (Table 2). The advice to beef producers is for them to check the relative prices before deciding on the method of supplementing the maize.
Cattle respond in rate of growth to the supplementation of maize silage with additional energy. Young cattle cannot eat sufficient maize silage to gain at satisfactory rates unless the silage is of very high dry matter content. It is at this stage that supplementary energy in the form of concentrates is particularly worthwhile. A young calf of 150 kg live weight given maize silage and urea without any concentrates cannot be expected to gain at much more than 0.5 kg/d. The 'feeding of concentrates at 1 kg per head per day raises the performance to approximately 0.7 kg/d and increasing this level to 2 kg increases the performance to approximately 0.9 kg/d.
The growth potential of the animal must be high in order to derive the maximum benefit from energy supplementation in the later stages of life, since excess energy is then reflected in
211 an increase in the fat content of carcass gain. Additional energy supplementation in the finishing stages is justified in some circumstances when it is necessary to increase the rate of finishing to meet trade requirements. This is particularly so with the late maturing breeds and crosses, such as Charoláis χ Friesian, and also with bulls.
In Britain, maize silage varies to a marked extent in dry matter content depending upon the season. Cattle fed on the wet material produced in 1974 had lower daily gains but these were still generally acceptable for the particular systems of production. Nevertheless, a high dry matter content is important because of the effect on intake, particularly with younger cattle. About 1 to 1^ kg of barley grain must be given with the lower dry matter silages to achieve the same performance as with the drier silages.
The performance of different types of cattle in different systems is shown in Table 7. Also shown for comparison are the results for feeding systems based on grass silage and hay. There was a consistent performance advantage to the maize silage units of nearly 0.1 kg/d. The slaughter weights and carcass characteristics of the maize silage cattle were typical of the production systems concerned.
TABLE 7 AVERAGE PERFORMANCE OF CATTLE ON MAIZE SILAGE
Overall daily gain (kg/d)
Friesian steers Hereford χ Friesian steers Large beef breed cross steers Other beef breed cross steers Beef cross heifers Slaughter Live weight (kg)
Dead weight (kg)
Finishing suckled calves
Maize silage
0.8
0.9 0.8 0.7 417 229
Other feeds
0.7
0.8 0.7 0.6 414 228
Finishing store 'cattle
Maize silage
0.9
0.9 0.9 0.7 428 237
Other feeds
0.8
0.8 0.8 0.7 427 235
Finishing 13 month beef
Maize silage
0.9
0.9 0.9
493 271
Other feeds
0.9
0.9 0.8
480 264
212 Table 8 sets out the average rations for the three systems
of production.
TABLE 8 DETAILS OF MAIZE SILAGE DIETS
Feeds (kg/head/d)
Maize silage Cereals Protein concentrates Other feeds
Concentrate costs (p/d)* Concentrate costs (p/kg gain)*
Finishing suckled calves
21.8 0.7 1.4 3.1
Maize silage
13.4
17.3
Other feeding systems
23.8
32.7
Finishing store cattle
25.9 0.7 1.5 3.5
Maize silage
16.4
20.1
Other feeding systems
24.2
31.4
Finishing 18 month beef
22.7 0.6 1.6 3.9
Maize silage
17.1
19.9
Other feeding systems
24.7
32.1
Maize silage - concentrates at £75 per tonne, other feeding system concentrates at £70 per tonne.
In all cases maize silage resulted in a lower feed cost per kg of gain, mainly by saving concentrates (a 60% lower concentrate cost per kg of gain). The saving in feed costs is not the complete story since this does not take account of the difference in output per ha of maize silage compared to many other feeds (Table 4).
Maize silage can be fitted into a whole range of beef systems but the most exciting prospects are for the arable farm where maize silage is used as the main feed for an indoor system of beef production. The two most likely applications in Britain are a feedlot system starting with the reared dairy-bred calf and the winter finishing of suckled calves and stores.
213 FEEDLOT BEEF
Feedlot beef on the lines of the Italian and Bavarian units has applications in Britain. Production experience is limited but production targets are given in Table 9.
TABLE 9 PRODUCTION TARGETS FOR MAIZE SILAGE BEEF FROM FRIESIAN CALVES
Overall daily gain (kg) Slaughter age (days) Slaughter weight (kg) Protein concentrate (kg) Silage dry matter (t) Cattle per ha (at 9.7 t silage DM/ha)
Steers
0.95 420 445 460 1.65 5.9
Bulls
1.05 420 490 460 1.75 5.5
It is probable that to achieve the fat cover on the carcass demanded by the market and the standards required for fatstock certification, the diet for bulls may need supplementation with 150 kg of rolled barley during the final finishing period. Financially, such a system at spring 1976 prices produces a gross margin of £100 per head and £490 per ha.
The equivalent gross margins per head and per ha for Friesian bulls sold at the same time from cereal beef units would be in the region of £48 and £130 respectively.
WINTER FINISHING SUCKLED CALVES AND STORES
One of the special attractions of maize silage for the winter finishing of suckled calves and stores is that'the quantity of maize silage available and its likely feeding value are known in advance of cattle purchases. This creates the opportunity for careful forward planning.
Production targets for Hereford crosses are shown in Table 10. Such a system would have produced a gross margin per head of about £65 compared with E30 per head for traditionally-fed cattle over the winter of 1975 to 1976.
214
TABLE 10 PRODUCTION TARGETS FOR WINTER FINISHING OF SUCKLED CALVES AND STORES ON MAIZE SILAGE
Live weight at purchase (kg) Feeding period (days) Slaughter weight (kg) Daily gain (kg) Protein concentrate (kg) Silage dry matter (t) Animals per ha (at 9.7 t silage DM)
Hereford cross steers Suckled calves
270 175 430 0.9 200 1.2 8.0
Store cattle
390 125 500 0.9 150 0.9 10.8
Animal Feed Science and Technology. 1 (1976) 215-226 215 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
DISCUSSION ON SESSION I
J.M. Wilkinson UK
It is obvious that there are very large effects of climate and of size of country on both the area of maize grown and the yield of maize per hectare. By comparison with the United States of America we have something like 8 million hectares currently grown in the countries represented at this conference. This compares with something just under 30 million hectares in the United States and a comparable area in Russia. We import nearly 20 million tons of maize each year and, of the countries here, only France is a significant exporter of maize grain. So this means that Western Europe is something like 50% self sufficient from what we can gather from projections of utilisation of maize by animals.
What I want you to do now, rather than discuss issues that will come up in later sessions, is to try to give some indication of how you see the situation developing in the future. For example , one or two speakers have made reference already to the yield of maize, in particular in the paper from Spain, and the paper from Portugal, the very large effect of irrigation. Yugoslavia has a tremendous potential for maize production and it would be very interesting to hear how Dr. Sreckovic and his colleagues see the area of maize developing in the future; for example, it may well be that Yugoslavia becomes a very large exporter of grain.
Where is that grain likely to go? Is it likely to come into Europe and replace American grain? Are we likely to see an increase in the proportion of maize grown for forage at the expense of maize grown for grain or, as we heard from several countries, is the area of grain likely to stay about the same and the area of forage increase? Are we likely to see an improvement, or an increase, in the proportion of maize silage in the diets of our beef cattle and, if so, will this release grain for feeding to pigs and to poultry?
I think these are the sort of things we should be considering and I am wondering whether, for our host country, Dr. Sreckovic would like to say a few words about how he sees maize production
216 in the future. Would you like to do that to start or would you prefer to wait?
A. Sreckovic Yugoslavia
A little later.
J.M. Wilkinson
OK. Anybody wish to say a little about how they see the maize situation changing in the future?
J.S. da Costa Portugal
In my country I believe that we can improve the yield per hectare in the south because at the moment we are constructing some reservoirs which can help us to increase the production per hectare if we wish to produce more feed than before. It is my opinion that for the EEC the utilisation of maize silage would be best and that we should increase the output of grain in our country. This is what I assume will be the case for my country over the next four or five years.
J.M. Wilkinson
It is interesting that one of the very large producers in Europe is West Germany where, in contrast to France, a very large proportion of the maize area is now occupied by maize grown for silage. Yet, Germany imports a lot of maize for its large population of non-ruminants. I wonder if they would like to comment on how things might develop in the future.
E. Zimmer West Germany
I can do it in a few words. We expect that maize for silage will be grown more in the north than it has been up to now because, as I said, two-thirds of the maize for silage is still in the south and this is going north. Maize for grain has already reached a peak and this is because of the limitations
217 of the available varieties. We don't think that we will increase our area of grain continuously in the future. Therefore, there is not a change of use from pigs to ruminants but it is a change in the rotations in the north and south of the country from grasses to maize, to have a higher yield potential. This is the problem in the northern part of Germany. In the southern parts we think we have a fairly stable situation. There is a completely different question; we are not sure whether we have the right philosophy in breeding. I would raise this question to the auditorium. Normally we breed our maize for grain but we use it as a whole crop, or as we would a grass, for forage, and we are not sure whether this is the right philosophy of breeding - whether we have the right parameters or not, if we are intending to feed whole crop maize to ruminants.
Maybe we can get some answers from other countries.
J . Z s c h e i s c h l e r West Germany
Mr. Chairman, may I give some additional figures about the aspects of maize growing in Germany?
J.M. Wilkinson
Yes, in a very short time please.
J. Zscheischler
You see from the graph (Fig. la) that the area of maize for grain is going down. We had a peak, as Dr. Zimmer has told you, but in maize for silage the line goes straight upwards (Fig. lb). What we can expect in future years up to 1985 is that we could have, especially in Bavaria, up to 330 000 hectares. In Bavaria we have about 50% of the whole crop from Germany. I can say from our standpoint in Bavaria, maize for silage and also for green products, just to take this maize fresh, will be going on especially in the south of our country.
218
Gr<-iph 1 fl
1000 ha 110 r
90 -
70 -
50 -
30
DEVELOPMENT OF MAIZE PRODUCTION IN WEST GEKMANY 116 / S^li 1964-75
toe
I i 1 L 1964 66 68 70
Graph l b
1000ha 400
350
300
250
200
150
100
50
Φ 74 1975
DEVELOPMENT OF MAIZE SILAGE IN WEST GERMANY 1964-75 420
0U
381
I I I J I 1964 66 68 70 72 74 1975
F i g u r e 1 LfALB
219
J . L . Blanco Spain
I think one of the possibilities of maize will be to use the whole plant more efficiently. What I have presented in my paper is to have the whole crop, grain plus green plant, but with mature grain, i.e. 37 - 30% moisture in the grain, as the raw material for the paper industry that separates each component in relation to its chemical composition. For example, 40% can be for feeding beef cattle; 17% for paper production; 41% will be rich in the amino acids of the grain and will be for human or animal consumption. This is the hypothesis of our presentation this afternoon. We think that if this emphasis can be built up, incomes per hectare will be twice what we have today. With this doubling of the incomes of the farmer it will probably increase the area devoted to maize in the country.
J.M; Wilkinson
Are you aiming to increase the area or the yield by using more irrigation?
J.L. Blanco
Both. If we can give the farmer more money per hectare we can improve the system of cultivation and also it will increase production and an increase in production will increase the area of cultivation.
Refsgaard Andersen Denmark
We are especially looking at what goes on in Germany and this moving north. It was mentioned in the paper this morning from Denmark that we have a very small area at the moment but farmers are interested in this. The problem is really that which was mentioned by Ireland - the big difference in yield.
I would like to put a question to the Germans. Were the figures in Dr. Zimmer's paper, Table 2, for yield per hectare typical of the whole of Germany? In Denmark, as in Ireland, we have from 6 to 12 tons per hectare, this was mentioned by Mølle
220
this morning. On the next page of Zimmer's paper there is a table of Yield and Nutritive Value in Different Regions. You show that in the Netherlands there is a lower DM content of the maize crop than in other countries. Is that the correct picture of the factors for maize in different countries or what is the explanation because that is our problem in Denmark, this low dry matter content and the problem of getting enough DM intake. It has been mentioned in the Danish paper that we have our root crop where we can get 7 000 or 8 000 units SE/ha with the top or with a high amount of protein and also the grass he mentions, that could be in that area. So these two could compete in Denmark and we look at those conditions before we make a decision.
E. Zimmer
Regarding your first question, this standard deviation of 7.3 was over the six year period and over all the regions of Germany. It is the published estimation of the yield from testing stations.
The second question - as you saw from the Table, I gave the authors and the year of their publication. Of course, this was the situation in the different countries in the different years, for example, the Netherlands' figures were published in 1971. I think Dr. Dijkstra took his samples in the previous years. I know from colleagues in the Netherlands that the situation was changing in the same way as it changed in the northern part of Germany, towards a higher and a more stable DM content over the years, so maybe now we are, in the northern parts, nearer 24% or 25% as an average over the years. I think this is the situation now in Northern Germany.
D. Oostendorp The fi ether lands
That is correct for the Netherlands. I think now the average would be around 25% - between 25% and 30% DM.
C. Lelong France
In France the grain maize acreage is at a ceiling and it is
221 quite unlikely to exceed 2 million ha of grain but only the yield can greatly increase now. For forage, if we have new varieties it is possible to increase the area mainly in the southern mountains below 500 to 700 metres. The area can surpass 1 million ha but probably will be very irregular because the climate of the last two or three years was very difficult for harvesting. We are developing wheat very quickly for beef feeding or cattle feeding in general.
J.M. Wilkinson
This is wheat as a forage crop?
C. Lelonq
Wheat as grain for animals, not for human consumption; also perhaps wheat as forage but for small farmers.
F. de Boer The Netherlands
I would like to refer to a remark made by Dr.. Zimmer and I think the remark was made by Dr. Kilkenny too, about the comparison of maize silage output against grass output. Dr. Zimmer's remark was that in the northern part of his country maize silage was gaining in area because it had a higher output per ha than grass. This has been stated very frequently in our country too, but we have the impression that the comparison is not always correct, but sometimes false, because one is comparing the output of maize as silage and not when it has been passed through the cow so it is not really the net output. When you measure net output of maize silage per ha then grass output and maize output seem to be about equal. So the reasons, in our country, that maize silage is still gaining in area are a little different from just this false comparison of maize silage output and grass output.
R.J. Wilkins UK
There seems to be rather an odd feature here in thinking
222 about the spread of maize silage and of maize grain, particularly to areas further north in Europe, in that, as Dr. Zimmer mentioned just now, most of the breeding effort in the maize crop, in Europe, is in relation to grain production and there is, certainly in the more northern countries, tremendous stress in this programme to increasing earliness, making the maize crop more suitable to move further north the maize crop for grain. How
ever, in reviewing this situation we have not really identified any country in the north of Europe, and Γ don't think in the south of Europe, where we are projecting further increases in areas of grain maize although the breeding stress is in that direction. This seems to me to be very odd. Dr. Lelong has suggested that we have had in the last few years two years perhaps a case where the climate has been particularly hard for grain maize. I am wondering whether we, in this room, are being rather pessimistic in our view on the potential for increased grain maize production further north in Europe and that we are being influenced by a couple of years of not very good climate. Why, if the plant breeders are breeding the grain maize and breeding for earliness, are we saying in effect that they are not going to get their results?
R.K. Phipps UK
I think part of the answer to Wilkins' statement is that many plant breeders still consider that the best grain varieties are also the most useful ones for forage. I will not go any further than to say that at the present time but I think that answers part of the question raised by Dr. Wilkins.
J.C. Tayler UK
In comparing the yield of grass with maize I think we must not ignore the difference in fertiliser input. Very often comparisons are made in terms of yield where maize is getting 150 kg of nitrogen per ha and grass will respond up to 300 or more kg of nitrogen per ha. I think in making this comparison we should be quite clear that there is a potential saving of the energy input as fertiliser with maize as compared with grass,
223
in situations where we are able to compare the two in similar sorts of climate.
W. Kaufmann West Germany
If we compare nitrogen fertiliser we have to consider the animal too, and there is a higher protein intake from grass which is wilted and on the other hand we should not only look at the energy/hectare but at the intake of other ruminants. Comparing maize silage with grass silages in the northern parts of Europe maize silage has too low a DM content and the intake is lower than the intake of very good grass silages.
J.B. Kilkenny UK
In Britain, when we are considering beef cattle as opposed to dairy cattle, we should be concentrating, not on the competitive elements of grass silage and maize silage, but on the fact that they are very complementary. The protein requirements of beef cattle are more than produced in grass silage but the intake and the growth of cattle is often disappointing. So we see grass silage and maize silage as being, in fact, complementary feeds suitable to be fed together.
J.M. Wilkinson
I wonder if our Belgian colleagues have any comments on the role of maize silage and its future development.
Ch. V. Boucqué Belgium
In Belgium there are still possibilities for increasing our area. Up to now it was beet which was replaced by maize silage. We had some 100 000 ha of fodder beet some ten years ago and now we have only 56 000 ha. With maize we have risen from zero up to about 80 000 ha. Why? The reason relates to the mechanisation problems. Fodder beet still gives a bigger yield of DM and net energy than maize but the labour requirement is higher for the fodder beet compared with maize. In any case, with our
224 varieties we have some fodder beet. It's not the same in Denmark where they have half sugar beet which can be mechanised very well. That is the reason why the area of fodder beet decreased.
Concerning the intake mentioned by Dr. Kaufmann, v/e did a lot of experiments with dairy cattle on the intake of different roughages and even when the DM of the maize silage was about 24%, it varied between 24% and 30%, we always obtained the highest DM intake per kg of bodyweight compared with every kind of grass. Very good young calves were fed on the silage and they came up to the same level but maize silage was always among the greatest intake levels. Even in 1972, when DM was only 20%, we found 12 kg DM intake per covi-very, very high. In the comparison with grass that Dr. de Boer mentioned, I think that we should not compare the output with freshly eaten grass but when those forages are used for silage. Then we have also to take into account the conservation losses with grass because they are larger than for maize.
F. de Boer
That's what I wanted to express but when we talk in Dutch we can make it much clearer probably! The reason is that when you have the net output of a hectare of grass and you compare it with the net output of energy from a hectare of maize, then the difference is not as much as is suggested many times when you read the literature or when you hear people talking about the comparison of maize and grass.
A. Sreckovic
For us in Yugoslavia it is very difficult for us to discuss this problem, comparing grass and maize, because we only produce maize. That is why the only possibility for us is to increase production by increasing the yield. That is why our main aim and official plan is to increase maize grain production within five years up to 12 million tons, reducing the total area by 300 000 ha, which means an increase of 25% in yield and a reduction of 13% of the area. That is a real possibility in our country.
225 Another possibility is to increase the total area under
maize for forage because we still do not produce enough of that form of maize.
Yet another possibility is that as suggested by Dr. Savie -to produce very soon some hybrids and varieties with a much higher protein content and even oil and especially lysine, increasing maize grain production and increasing protein production. That is our plan.
J.M. Wilkinson
Is the object to export this maize grain or to feed it to livestock?
A. Sreckovié
Yes, we export already. We export some commercial maize grain - 2 million tons - and we export a great deal of seed to different countries all over the world. We hope, of course, that this trade will increase in the future.
J.M. Wilkinson
Can I have a comment from Dr. Vetter on the likely change, if any, on the output of maize grain from the United States? We do depend very heavily, as we have seen from the papers already, on imported grain from the United States. What are the trends?
R.L. V e t t e r United States of America
Concerning the comment on the effect of silage varieties versus grain varieties, the common consensus of opinion in the States is that we go for grain production in our silage because we are looking for energy in the silage also. In comparisons, we seldom see a good silage variety out-yielding in total energy per acre our grain varieties, but that's under harder conditions.
Secondly, the feeling is that we have probably reached near optimum yields considering our yields and area in production.
226
New land areas going in, unless under irrigation, will be much lower yielding, as we saw in these last two years particularly in Iowa where we were breaking up land. Parts of Iowa and Illinois could consider irrigation but do not have the water supply available without very high cost.
The general consensus is that irrigation would only be in much more restricted areas. So, I would think that we are near our production potentials unless we see an all-out effort made.
There is the strong possibility that we could see a shift in the areas of milo or grain sorghum production now which are under irrigation, we could see a shift to maize for grain production fairly easily. If the price goes high enough then I think we would see that shift taking place.
J.M. Wilkinson
We have come to the end of the time and it seems to be generally accepted that an increase in either yield or the area or both, of maize, is desirable, and, in some countries, absolutely necessary in order to maintain desirable levels of livestock population and also to try and reduce dependence on imported supplies. There is the unresolved problem of suitability of varieties which we can possibly discuss again in the next session. There is also the unresolved question of the desirability of feeding ruminants on large quantities o£ maize grain, which no doubt we will also discuss in later sessions.
227
SESSION I I
THE EFFECT OF AGRONOMIC FACTORS ON THE YIELD AND COMPOSITION OF
THE MAIZE CROP, CONSIDERED IN RELATION TO THE METHOD OF USE OF
THE CROP
Choice of va r ie t y i n r e l a t i o n to s o i l , c l imate and e levat ions j s o i l c u l t i v a t i o n ; sowing methods and p lant populat ions! f e r t i l i s e r s and manure; con t ro l of weeds and pests¡ i r r i g a t i o n ; double cropping and crop ro ta t i ons .
Animal Feed Science and Technology, 1 (1976) 229-236 2 2 9 Elsevier Sdentine Publishing Company. Amsterdam - Printed in The Netherlands
THE USE OF TECHNIQUES OF MAIZE CULTIVATION TO MAXIMISE FEED FOR BEEF PRODUCTION
R. SAVIC Faculty of Agriculture, Novi Sad, Yugoslavia.
Maize and cattle production have many points in common. This is confirmed by the fact that the regions with a large-scale production of maize are also important cattle producers. In practice, the entire maize plant, minimally supplemented with other feeds and ingredients, is quite suitable for the nutrition of young as well as mature animals.
The following facts should be considered: a) Maize stalks gathered from 1 ha are sufficient feed
for one animal because this quantity, according to its starch value, equals 0.6 ha of hay or 0.3 ha of alfalfa.
b) Grain, cobs and stalks with leaves provide feed the value of which ranges between 8 000 and 12 000 starch units. The above figures are for the Danube valley, with normal agro-technical measures applied on unirrigated plots in a normal year.
c) Maize production, particularly grain production, can be relatively easily increased through breeding for new hybrids and the improvement of the present agro-technical measures.
d) Maize breeding develops cultivare suitable for mechanised production, with improved qualities of grain and stalks, i.e. with higher contents of sugar, oil, protein, lysine, amylopectin, etc.
If the above facts are taken into consideration, it can be concluded that maize is a rather valuable crop and that efforts to maximise the production of maize for cattle feed deserve our full attention. However, there are still open questions regarding the directions of work on both maize breeding and maize agro-techniques.
ECONOMY OF PRODUCTION AND UTILISATION OF MAIZE
The present-day maize hybrids have the ratio, grain:other plant parts, 1:0.8-1. The total dry matter ranges from
230
15 - 16 000 to 20 - 25 000 kg. The objective of maize production is to produce more
in a better, simpler and cheaper way. However, this problem is modified by the extent to which intensification depends on the maize producer and how much it depends on the supply of agricultural machinery, fertilisers, chemicals and fuel, on taxes and other costs which cannot be controlled by maize producers.
In terms of cattle feeding, the problems stem from the different ways in which maize can be used viz: 1. whole plant either fresh, dehydrated or ensiled; 2. ground, fresh or dried grain and cobs; 3. ground, fresh or dried grain; 4. ground dry cobs; 5. ensiled or dehydrated stalks without ears; or other combinations, depending on habits and technical capabilities of maize and cattle producers and on the purpose of cattle production.
However, changes in the methods of production and in the nutrition of cattle require a change in habits and new, and frequently high, investments in machinery and buildings.
Research into new techniques is undoubtedly necessary. However, progress is in most cases, a function of the economic effects of production since the economics of maize production are not directly correlated with yield - it is rather a correlation between finances expended and the prices achieved for the product.
In modern maize production (Gyorfi, 1975) 1 kcal of energy invested into production brings 2 kcal of grain (around 11:22 million kcal). The efficiency of utilisation of invested energy is obvious and rather high. However, there is a disproportion between the price of each kcal used and the price of each kcal produced, particularly if the fact is observed that about 20% of the total energy is used for drying, a further 25% is used by field machines and for transportation, while 45% is used for mineral fertilisation.
Beeson (1962) drew attention to the fact that 40% of the total digestible nutrients of the maize crop is contained in the cobs and stalks. He calculated that 1.5 acres (0.6 ha) would provide sufficient cob and stalle silage to maintain a beef cow producing one calf per year, and also drew attention
231
to the value of the fibre in cobs and stalks included in diets for cattle fattened in feedlots.
If, in cattle nutrition, the use of costly dried grain, which is frequently of decreased nutritional value, becomes prevalent over other plant parts, or these parts are entirely omitted, neither the best agro-technical measures nor the highest yielding hybrids can lead to profitable maize production, nor can the maize be regarded as the major component in nutrition for cattle production. There is a simple question - what type of production can be profitable if about 40% of usable products are thrown away?
TECHNOLOGY OF MAIZE PRODUCTION (GRAIN AND SILAGE)
Maize production in conditons without irrigation still largely depends on the climatic conditions of the year of growing. In all regions with average precipitation levels under 250-350 mm during the period of growth of maize, production is unstable and risky, particularly in the case of an irregular pattern of precipitation, in spite of sufficient reserves of winter moisture.
In such conditions, only an early planting of maize as the main crop is secure whereas second or additional plantings are largely uncertain.
This is why the producers who grow maize in unirrigated plots in arid or more favourable regions should strictly follow agro-technical recommendations in order to secure high and stable yields. These recommendations include the following items: ploughing time and depth, fertiliser type and quantity, planting time and density, weed and pest control.
Maize production in the Vojvodina plain can be used as an example. The plain, which has variable soils and a semi-arid climate, is the most important maize-producing region in Yugoslavia. In the period from 1948 - 1966, the mean yearly precipitation level was 601 mm, the mean yearly temperature 10.9°C. In the period from 1950 - 1970, the average precipitation level for the period of maize growth (April -
232
September) was 341 mm. In 1971, however, there were only 198 mm of rain; in 1975, on the other hand, 534 mm. It should be pointed out that in these two years there were considerable variations in precipitation in different parts of this relatively small region.
Ploughing time and depth: Two ploughings are usually performed. The first, shallow one, includes the ploughing in of the remains of the preceding crop, the second, a deeper basic one, follows. Basic ploughing for maize ranges from 30 - 35 cm. A depth of 25 cm is also satisfactory provided that ploughing for the preceding crop was deep.
The time of ploughing is an exceptionally important factor in the level and economics of maize production. According to Pavlovié et al. (1975), at the agro-industrial complex PIK "Tamia", Pancevo, in the period from 1971 - 1974, the grain yields of all maize hybrids examined decreased regularly and steadily with delay of the basic soil cultivation (Table 1). This finding applies to the entire maize production in Vojvodina, with understandable exceptions in certain months and years.
TABLE 1 EFFECT OF DATE OF CULTIVATION ON YIELD OF MAIZE GRAIN
Month of basic cultivation
July August September October November December January February March April May
Mean
Area (ha)
148.0 2 045.0 5 090.0 2 070.4 5 393.2 4 816.3 339.0 40.0 22.0 30.0 10.0
-
Grain yield (t/ha)
7.61 6.67 6.31 6.10 6.00 6.49 5.49 5.79 4.95 5.36 6.70
6.28
233
Fertiliser .type and quantity: The application of the most suitable quantity and kind of fertilisers is a regional question and it depends on the type of soil in the area planned for maize production and its content of minerals.
According to long-term examinations and the resulting experience (Drezgic and Markovic, 1975), it was concluded that on normally cultivated and fertilised soils, the production of about 10.0 t/ha of grain and 8.0 - 10.0 t/ha of air-dry stalks can be secured in Vojvodina with the application of 300 kg of pure nutrients in the ratio NPK = 1.0:0.8:0.6. The common procedure is to apply larger portions of phosphorus and potassium and a smaller portion of nitrogen before the basic cultivation. After that the nutrients in the ratio 1:1:1 are applied at the time of planting. Finally, one top dressing with pure nitrogen is performed at the stage of 7 - 9 leaves. There is a tendency to decrease the number of fertiliser applications to two, or even one, which would be performed before the basic cultivation.
Planting time and density: One of the important conditions for successful production is the earliest possible planting. Contemporary maize breeding is aimed at the development of genotypes suitable for particular agro-ecological conditions. In colder and usually humid regions of Europe, the seed should germinate and sprout in cold and moist soils and should bring, at the desired time, the highest possible grain yield or green forage and grain for silage.
In warmer and drier regions the seed should sprout in the soil which is frequently cold and dry but should be tolerant to high temperatures and drought in the course of vegetative growth.
As a relatively large number of hybrids with different lengths of growing period is presently used, it is necessary to learn as much as possible of their optimal planting density. The problems of optimal density and the maintenance of the desired number of plants per area unit until harvest are the final factors of grain and green forage yields.
In Vojvodina, for example, because of variability in its climate, it is recommended to plant 5 5 - 6 5 000 plants/ha for early hybrids (FAO 300 - 500) and 45 - 55 000 plants /ha for
234 late hybrids (FAO 600 - 800) for the production of grain and silage. Between 10 and 15% more viable seed should be planted in order to make up for possible but undefined losses in seed or plants which may occur during sprouting and growth. For the production of green forage, it is recommended that the figures given above should be increased by 20 - 25%. Equal planting density is recommended for the planting of maize as a first and a second crop.
The data for the period 1971 - 1974 gathered at the agro-industrial complex PIK "Sirmium", Sremska Mitrovica, by Stanisavljev et al. (1975), show the dependence of grain yields on the density at the time of harvest (Table 2).
TABLE 2 EFFECT OF PLANT DENSITY ON YIELD OF MAIZE GRAIN
Plants/ha
37 500 40 200 45 400 48 900 50 100
Mean
Area (ha)
3 901 11 013 14 146 4 632 2 036
-
Grain (t/ha)
4.66 5.81 7.03 7.92 9.03
6.62
Profitable maize production can be achieved through the planting of so-called full season maize. In view of climatic conditions it means that hybrids FAO 100 - 200 are full season maize in certain regions while hybrids FAO 700 - 800 are full season hybrids in others (Savie et al., 1975).
On the other hand, the complaint that late hybrids are a bad preceding crop because of late harvest, that the drying of grain with a high percentage of moisture is expensive, and that there is about 80% of water in the green parts of these hybrids transported for silage, can hardly be even partially justifiable in view of the present knowledge of cattle nutrition and the present technical possibilities.
235
Proper grain drying in a well organised maize harvest and transportation is carried out at a grain moisture of 35 - 40%, at which point the higher level of production makes up for the somewhat higher expense of drying.
When entire maize plants (grain, cobs, stalks) or only cobs and stalks are intended for silage, and stalks are cut 35 - 50 cm above the ground, the lower plant parts which contain the highest amounts of water (over 80%) and the lowest amounts of digestible constituents are left in the fields to be ploughed in.
In the production of concentrated silage (whole plant cut 35 - 50 cm above the ground) with 30 - 35% of dry matter at the time of ensiling (Palusek and Jerkan, 1975), nearly 50% of the total dry matter produced is in the form of grain (a yield of 7.2 t/ha). This means that pure grain has approximately the same nutritive value as 40 - 50 000 kg/ha of silage produced in densely planted plots with maize stalks cut to the ground, i.e. the silage made of reduced maize plants (the stalks cut 35-50 cm above the ground) with natural moisture contain about 38% more nutritive units than silage made in the normal way with higher planting density.
The possibility of using whole-crop maize for cattle nutrition means an increased utilisation of yields even if the present grain yields are not increased (Mutic, 1975).
CONCLUSION
Maize plants are abundant providers of quality cattle feed, i.e. they are first-rate feeds for both young and mature animals. In unirrigated plots, entire maize plants can yield between 8 000 and 12 000 or more starch units per ha.
In order to make the production of maize and cattle as economic and nutritious as possible, whole maize plants should be used for cattle nutrition in the form of concentrated silage because the production of dried or dehydrated grain is more expensive, while artificial drying may reduce grain quality.
In the production of silage from full season maize, the highest possible quality and cheaper yield of grain, cobs and stalks are obtained if the density is the same as for grain production and if maize stalks are cut 35 - 50 cm above the
236
ground. At the same time such production enables an easier and timely soil preparation for the following crop.
REFERENCES
Beeson,W.M, 1962. Production and nutritional developments in beef cattle. Report at the National Beef Cattle Conference, Ames, Iowa, USA.
Drezgic, P. and Markovic, Z., 1975. Maize agrotechniques present results and prospects of further development. Report at the Consultations on Maize in Vojvodina, November 1975, Duboka, "poljoprivrednik", Novi Sad, pp 29 34.
Györfi, Β., 1975. A kukorica korszerü agrotehnikája (manuscript) (Contemporary maize agrotechniques). Report at the Bajai Kukoricatermelisi Rendszer, Budapest.
Mutic, Ζ., 1975. Technology and technique of contemporary maize picking, preservation, and utilisation for cattle nutrition. Report at the Consultations on Maize in Vojvodina, November 1975, Duboka, "Poljoprivrednik", Novi Sad, pp 67 75.
Palusek, I. and Jerkan, Μ., 1975. Experiences in preparation and utilisation of concentrated silage for forcefed cattle nutrition. Report at the Consultations on Maize in Vojvodina, November 1975, Duboka, "Poljoprivrednik", Novi Sad, pp 77 80.
Pavlovic, I., Stojkovic, D. and Djordjevic, Μ., 1975. Characteristics of maize production at PIK "Tamis" in the period 1971 1974. Report at the Consultations on Maize in Vojvodina, November 1975, Duboka, "Poljoprivrednik", Novi Sad, pp 113 121.
Stanisavljevic, D., Petrov, P., Vasic, V., Zunkovic, P., Stepanovic, V. and Milosevic, M., 1975. Production of maize at PIK "Sirmium" and in cooperation. Report at the Consultations on Maize in Vojvodina, November 1975, Duboka, "Poljoprivrednik", Novi Sad, pp 123 137.
Savie, R., Vidojevic, Z., Saric, T., Jakovljevic, L., Gajic,M. and Sultan, Μ., 1975. The role and prospects of breeding in the improvement of maize production. Report at the Consultations on Maize in Vojvodina, November 1975, Duboka, "Poljoprivrednik", Novi Sad, pp 9 12.
Animat Feed Science and Technology. 1 (1976) 237-243 237 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
CULTIVATION OF MAIZE IN IRRIGATED AREAS FOR SILAGE AND GRAIN PRODUCTION AND THEIR USE BY RUMINANTS
A. MONTEAGUDO Department of Cereals,INIA, FINCA EL ENCIN, Box 127, Aleóla de Henares, Madrid. (Spain)
The increase in yields in recent years in Spain is due to diverse factors. Not only was the use of hybrids concerned in the maximum production of maize, but also irrigation and other cultural practices were involved. The importation of maize grain mainly for the feed industry, has also increased, ranging between 3.5 and 4.5 million tonnes. The total yield of grain on the other hand, remains at over 2 million tonnes per year.
At present, 60% of the total area used for grain production is irrigated. With an irrigated agriculture, the farmer can fertilise, plant and plan with confidence for a maximum production. The summary of yields in the trials on grain production during three years in every Spanish region indicates that it is possible to increase the level of production (Table 1). The regions with the greatest area of irrigation are Ebro, Andalucía and Extremadura, where the normal yield represents only 60% of the yields of the trials. Many problems are involved in increasing these yields; although we know a great deal about it, much remains to be learned.
Water is the most important factor in maize production. Irrigation allows man to control this factor of production to varying degrees. The yields are related to efficient irrigation. This irrigation efficiency might be defined as the relationship of the water retained in the root zone from irrigation to that delivered to the field. The water losses which occur are from evaporation (water surface), deep percolation and runoff from irrigation.
On sandy soils with high intake rates and low water holding capacities, most of the water loss is due to deep percolation. On clay soils, low intake rates, and runoff, are the major problems because the water must be kept in the furrows during a period of many hours, in order to get water to penetrate the soil.
238
TABLE 1 YIELDS IN t/ha OF THE TRIALS FOR GRAIN PRODUCTION DURING THREE YEARS IN COMPARISON WITH THE NORMAL YIELD IN SPAIN
Zone
Cantábrico Ebro Cataluña Duero Centro Levante Extremadura Andalucía
Mean
Annual mean
Yield (t/ha)
6.42 7.05 7.93 7.43 7.67 8.68 9.29 8.30
7.85
Number of trials
4 3 . 3 3 4 2 3 4
3.3
Maize irrigated
Area (000 ha)
21.1 81.8 31.9 17.9 18.5 21.2 49.6 51.0
36.6
Yield (t/ha)
4.00 5.71 6.58 4.15 5.61 4.88 4.00 5.07
5.09
TABLE 2 YIELDS OF MAIZE GRAIN (t/ha) WITH TWO PLANT DENSITIES AND THREE FREQUENCIES OF IRRIGATION
Number of applications of irrigation (a)
3 6 12
Mean LSD (0.05)=0.47
Density (b) plants/ha
30 000
4.58 5.56 6.65
5.60
60 000
4.86 7.00 8.60
6.82
Mean LSD (0.05)=0.84
4.72 6.28 7.62
6.21
CV (a) = 11.9% CV (b) = 10.5% Number of irrigations = HS Density = HS Interaction
Two densities at same number of irrigations LSD (0.05) = 0.82 Two 'number of irrigation' means at same density LSD (0.05) = 1.13
239 In order to obtain uniform water penetration on all parts of
a field, the field should have a uniform grade or slope. Land grading is required on most fields to get this uniformity of slope. This not only provides the slope desired but also provides good surface drainage. Drainage is just as important for high production as irrigation. Efficient irrigation may allow 3 for the production of 100 kg of corn for 60 m of water, while inefficient irrigation may require 120 - 150 m of water to produce the same amount of corn. (Fischbach, 1959)
Water is removed from the soil by evaporation from the soil surface and by transpiration through the leaves of the plants. Most of the water that is used by transpiration through the leaves occurs from the rapid growth stage through the milk stage for maize. Optimum soil moisture within the root zone at.these stages is important for high yields. A good method of determining the available moisture in the soil is with the tensiometer. The tensiometer evaluates the water use, the moisture in any soil, and the penetration of water and the tensiometer tells when to irrigate and when to stop irrigating.
Robins and Domingo (1953) investigated the effect on corn yields of allowing plants to deplete the soil water to the permanent wilting point at certain stages of development. A soil water deficit maintained for one or two days during tasseling or silking reduced grain yields 22%, and soil water deficit for 6 - 8 days during this period reduced yields 50%. Denmead and Shaw (1960) also found that soil water stress at silking was more harmful to grain yield than stress at any other time.
The number of applications of irrigation during the different stages of development of maize has been found to affect yields (Table 2). With only three applications there was little yield difference between stands of 30 000 and 60 000 plants/ha. However, with a greater number of applications (6 or 12) plant density was of great importance and unless density was increased the benefit of this higher water supply was not sufficiently utilised. In other words, if it is dry, there is no advantage of higher population, but if moisture conditions are more favourable (12 irrigations), one can expect considerable benefit from higher plant density.
240
TABLE 3 YIELDS OF MAIZE GRAIN, t/ha, WITH TWO PLANT DENSITIES AND FIVE TYPES OF PLANTING
Number of plants per hill (a)
1 1.5 2 3 4
Mean LSD (0.05) = 5.1
Density (b) plants/ha
30 000
8.41 7.80 8.51 8.26 7.94
8.18
60 000
9.67 8.55 9.70 9.54 10.16
9.52
Mean
9.04 8.18 9.11 8.90 9.00
8.85
Number of plants per hill = NS Density = HS Interaction = NS Two density means at same number of plants per hill: LSD (0.05) = 1.13
TABLE 4 YIELDS OF MAIZE GRAIN, t/ha, WITH TWO CLASSES OF MATURITY AND THREE PLANT DENSITIES
Class of maturity (FAO) (a)
400 800
Mean LSD (0.05) = 0.55
Density (b) plants/ha
30 000
6.47 9.00
7.73
60 000
9.27 9.96
9.61
90 000
7.95 9.70
8.82
Mean LSD (0.05) = 0.29
7.90 9.55
8.72
CV (a) = 3.9% CV (b) = 5.8% Hybrid maturity = HS Density Interaction = ΗΞ Two density means at same hybrid maturity LSD (O.05) = 0.82 Two classes of maturity at same density LSD (0.05) = 1.13
241 Yield increases with population until competitive effects
become important. Yield per plant then begins to decrease but yield per ha continues to increase until the competition is such that grain yield per ha 1-egins to decline. The optimum plant population level may vary markedly according to changes in agro-climatic conditions or in variety. In Spain, in the irrigated zone, the optimum plant density lies betweeen 40 000 and 80 000 plants per ha.
The desired plant population may be obtained with a large number of combinations of between-row spacings, within-row spacing and number of plants per hill. The trials made to find the influence of the check row did not give significant results (Table 3). In general, the highest yields are obtained with one or two plants per hill in all densities with a late hybrid (FAO 800) .
Early hybrids many times approach the yield of later maturing hybrids when planted at a heavier rate, but it has not been true for all early hybrids. The yields of two classes of maturity (early and late) at different densities were similar at 60 000 plants per ha but for early hybrids yield decreased at the lov; population and over all (Table 4). There was no association between the average yielding ability of a hybrid and its response to increased plant population. The ability to give a larger response to increased population tended to be a variety characteristic to some extent. The interaction between maturity and population was highly significant in our trial.
The quality of grain is important, because the maize crop is primarily grown for food, feed and fodder. The percentage of protein in the grain is different in several single crosses, but we find a significant correlation (r=0.417**) between "class of grain" and protein content. The class of grain was measured with a classification of 1 to 5 for dent to flint. (Table 5). In the flint group, we can obtain hybrids with a percentage of protein near to 15%. The percentage of protein in the grain decreases with the yield and with the increase in plant population, but increases with the application of nitrogen. Actually with the use of the infra red analyser we can more easily increase the percentage of protein by breeding in new hybrids.
242
TABLE 5 PROTEIN AND LIPIDS FRACTION OF MAIZE GRAIN IN DIFFERENT SINGLE CROSSES IN RELATION TO TYPE OF GRAIN (% DM)
Class of grain Type
Dent Semiflint Flint
Total
Classification
1.5 - 2.5 3.0 - 3.5 4.0 - 5.0
1.5 - 5.0
Single crosses (No.)
21 17 34
72
Protein (%)
Mean
11.22 11.33 12.44
11.81
Deviation*
9.15-13.29 9.85-12.81 9.65-15.23
9.25-14.37
Lipid (%)
Mean
5.71 6.09 6.81
6.33
Deviation*
4.59-6.83 4.88-7.30 5.61-8.01
4.81-7.85
Correlation between class of grain: protein = 0.417** and lipids = 0.628** * Deviation values: (m - 25) to (m + 25)
TABLE 6 FORAGE PRODUCTION FROM CROPS OF DIFFERENT CLASSES OF MATURITY
Class of maturity (FAO)
600 700 800
Mean
Yields of forage (t/ha)
69.14 73.30 83.60
75.34
Yields of dry matter Total plant
(t/ha)
17.70 16.20 16.47
16.79
Ears (t/ha)
6.27 5.07 2.91
4.75
Dry matter (%) Total plant
25.6 22.1 19.7
22.5
Ears
29.1 24.4 18.5
24.0
Relation of ears/total plant (%) (dry matter)
35.42 31.30 17.67
28.13
TABLE 7 CHEMICAL COMPOSITION OF FORAGE OF DIFFERENT CLASSES OF MATURITY (% DM)
Class of maturity (FAO)
600 700 800
Mean
Dry matter
25.6 22.1 19.7
22.5
Protein
8.68 8.97 9.05
8.90
Lipid
2.36 2.09 1.68
2.04
Starch
62.16 60.96 57.16
60.09
Fibre
22.86 24.06 27.95
24.96
Ash
3.94 3.92 4.16
4.01
243
In Spain more than 100 000 ha are sown for maize silage which is normally consumed by ruminants, t'aize for silage can be harvested after silking but the dry matter yield, TDN and total protein yield are higher if the crop is harvested when the grain has reached the dough stage. The yield of forage is higher in the later hybrids (FAO 800), but the dry matter yields in the trials are the same in all the hybrids with different classes of maturity (Table 6). The proportion of ears in the total plant dry matter also decreased with later classes of maturity. The chemical composition of the forage indicates more dry matter in the earlier hybrids (FAO 600) but no greater content of protein (probably an effect of the characteristic of every hybrid) more ether extract and less crude fibre (Table 7). Maize has no competitor among the silages, not because it presents a better nutrient spectrum, but because of crop yield and the little attention required to make good silage. Under normal conditions, the maize will ordinarily yield more dry matter per unit of land than will the other silage crops.
REFERENCES
Denmead, O.T. and Shaw, R.T. 1960. Effect on corn yields of moisture stress at different stages of growth on the development and yield of corn. Agron. J. 52: 272-274.
Fischbach, P.E. 1959. Efficient use of irrigation water. Proceedings of fourteenth annual hybrid corn industry research conference: 85-93.
Robins, J.S. and Domingo, C.E. 1953. Some effects of severe soil moisture deficits at specific growth stages in corn. Agron. J. 45: 618-621.
Animal Feed Science ami Technology. 1 (19761 245-250 245 Llscvier Scientific Publishing Company. Amsterdam - Primed in The Netherlands
SELECTION OBJECTIVES FOR MAXIMUM YIELDS OF FEED WITH HYBRID MAIZE
J.L. BLANCO Departamento de Investigaciones Antropológicas y Genéticas de Barcelona, Consejo Superior de Investigaciones Cientificas, Zona Universitaria de Pedralbes, Barcelona 14, Spain.
To optimise feed production and cost, the research under way at the Department of "Investigaciones Antropológicas y Genéticas" points out the following objectives:
a) Inheritance and breeding for character directly related to photosynthetic capacity per plant, as a way to increase photosynthesis per hectare,
b) Breeding for high sugar content in the stalk at maturity, and essential amino acids of the grain,
c) Industrial processing of the total maize crop to reduce the cost of the feed for cattle, versus ensilage.
a) To increase photosynthesis per plant and per ha, we are studying the effect on the magnitude of the total surface of the plant leaves of the genetic complex that we call "decussate" because the plants with this character have opposite leaves (and opposite ears) and in two crossed directions, alternately along the stem. This genetic complex has other effects (some are defects and we are eliminating them by selection). Its effect on the total magnitude of the leaves per plant varies, depending on the interaction with the genetic background; in some stocks it increases the total surface of leaves per plant by only 50%, while in others this increase reaches 100% of that of the original normal stock.
The inheritance of this character is very complex; at least it is multifactorial, with some genes dominant and others recessives.
246
We are expecting through this character to increase the capacity of synthesis per plant for a better economy of its carbohydrates, to the benefit of the proportion of production of starch and sugars per unit of dry matter, per plant and per ha.
The last step of this part of research should be to compare the performance of normal hybrids and their corresponding "decussate" versions, in different degrees in plant populations, but there remains a great deal of work ahead in research and breeding.
b) At the 1956 FAO Maize Meeting for European and Mediterranean Countries, held in Cairo, we presented the first results of selection for high sugar in the stalk at grain maturity, (Blanco and Blanco, 1956). We have already developed several hybrids of different periods (from 300 to 800 FAO). The sugar in the stalk at maturity in these hybrids is around 31% of the dry matter. The amount of sugars per ha from these hybrids when cultivated in good conditions, under irrigation, in Spain, amounts to more that 3 500 kg/ha. Nevertheless, we think that better results can be achieved. Research and breeding should be intensified (Blanco et al., 1957) because the net energy of these sugars, as a feed for ruminants, is equivalent to 1/3 of the net energy of the grain and, in relation to the net energy of the whole plant of maize, (grain plus straw) it is an increase of 21%.
The use of these hybrids for silage has the advantage over the standard hybrids that they remain green, and the stalk contains plenty of juice, when the grain is matured: the dissolved solids of the stalk juice range from 10% to 18% when the grain contains between 37% and 30% moisture.
When ensiling standard hybrids (at the doughy-hard stage) there is a sacrifice of 10% to 15% of the starch of the grain, but with high sugar hybrids the harvesting for ensiling can be delayed until full maturity and this loss is avoided.
We did not find any negative correlation between high sugar in the stalk at maturity and grain yield; on the contrary, there is evidence that selection for high sugar content in the stalk increases the capacity for total dry matter synthesis and adaptability (Blanco, 1972). In fact, the hybrid "España 22",
247
with high sugar in the stalk, achieved the greatest yield in all the trials we carried out in Spain during more than 10 years, in many factorial combinations, including different populations (ranging from 50 000 to 100 000 plants per ha). Top yields achieved were of 17 500 kg of dry grain per ha with a population of 75 000 plants per ha, under irrigation; and the highest green matter yield at maturity was 113 t/ha.
Research and selection for high lysine and trytophane looks very promising. Several researchers are finding interactions that compensate the losses in yield of the "Opaque 2" gene (Paez et al., 1969). We found such interactions too, and in some stocks we found interactions that triple the lysine (while the normal effect of "Opaque 2" is to double lysine in relation to the normal maize (Nelson, 1969)). We are introducing the high lysine character into our high sugar hybrids. The relationship of this breeding programme with beef production depends firstly on the feeding value of high lysine maize to feed weaners and secondly to save the grain for monogastric animals and men and to feed cattle with the cheaper part of the plant. When ruminants are fed with maize grain we use feed suitable for monogastric animals. If maize grain is rich in lysine it should be saved for human nutrition.
Beef production should become cheaper if ruminants are fed only with the plants of maize while the grain is kept for more specialised uses. The question depends mainly on the limits for dry matter and fibre ingestion per ration, in relation to the needs for net energy, Total Digestible Nutrients and palatability for optimal economic production.
To discuss this we shall consider the standard limits and needs of the ration to feed calves of 272 kg and one year old, for beef production (Morrison, 1949):
Maximum dry matter, 8 kg. Minimum net energy, 9.7 Meal Minimum Total Digestible Nutrients (TDN), 4.9 kg. Then, the minimum energy per kg of DM is 1.21 Meal and
the minimum TDN per kg of DM is 0.61 kg. If we consider the composition of maize straw plus cob
(no sugar or grain) of standard hybrids, the concentration of the net energy is 0.78 Mcal/kg and 0.57 kg TDN/kg of dry matter.
248
For the high sugar hybrids we estimate that the net energy is 1.09 Meal and 0.72 kg TDN/kg of dry matter of the crop. To feed calves with the stover of the standard hybrids, and for the limit of 8 kg of dry matter in the ration, there would be a deficit of 7% TDN and 35% of net energy. With the plants rich in sugar in the stalk (but without grain) for the same limit of 8 kg of dry matter in the ration, there would be an excess of 18% of TDN and a deficit of net energy of 10%. On the basis of a yield of 8 000 kg/ha of maize grain, at 15% moisture, and considering the corresponding yield and composition of plants/ha this means that to compensate for the deficit of energy, in the first case it is necessary to add to the straw and cobs of one ha, 4 564 kg of grain, but in the second case only 1 503 kg of grain is required. The difference is 3 061 kg of grain that can be saved per ha, or, for the 1 797 rations that can be supplied with the straw of one ha of standard hybrid it should be 3 433 kg of grain to obtain the same beef production with any one of both rations.
c) To make cheaper the feed for ruminants there is yet one other alternative.
The vascular bundles are around 60% of the weight of the stalk. These fibres are the component of the stalk which has the lowest feeding value but provides a good raw material for paper production. If this fibre were separated in the proportion of 55% of the dry matter of the stalk, the rest of the stalk, (sugar, pulp, etc.) plus the leaves, etc., would have per kg of dry matter, 0.73 kg TDN per kg (this has an excess of 19%), and the net energy is 1.23 Meal per kg, then, there will be no deficit in net energy and with such feed all the grain would be saved. For this calculation we give to the remaining part of the stalk (the pulp) 1.04 Mcal/kg and to the fibre the same value as to the straw of wheat, 0.22 Mcal/kg (Morrison, 1949). This needs to be investigated experimentally.
Stalk fibre for paper production has a price that is equal or superior to many fodders, although there are different values in different countries. Different combinations of the components of maize plants and grain can also be made to get different relations of net energy to dry matter and to add protein or non-protein nitrogen to the feed.
249
On the basis of a yield of 8 000 kg/ha of grain with the hybrid "Espana 22", we calculated a production of:
Feed for beef production of 1.23 Mcal/kg 7 795 kg = 40.8% Fibre for paper 3 355 kg = 17.5% Grain, rich in amino acids for men or for monogastric animals 8 000 kg = 41.7%
Total 19 150 kg = 100%
Several questions remain to be investigated for optimal industrialisation of hybrid maize rich in essential amino acids in the grain and sugar in the stalk at maturity, to optimise the cost of the ruminant product. For example:
a) Which is the optimum of fibre extraction in relation to actual and net energy production of this fibre, and in relation to the price of the cellulose for paper?
b) Different alternatives of harvesting, drying and processing the matured and green crop of maize with high sugar.
c) Cost of financing, operating, etc. of such processes. On the basis of Spanish prices we estimate that a cheap
feed for ruminants can be produced with such transformation and that the added values per ha of all the products equal the value of the grain per ha. Which part of this extra value will be consumed by the industrial process and which part will be saved in benefit of the price of feed for cattle? This question should be answered with experience of nutrition and of pilot industrial processing of the whole maize crop.
REFERENCES
Blanco, J.L. and Blanco, Μ., 1956. Maize hybrids with high sugar content in the stalk at grain maturity. Ninth FAO Hybrid Maize Meeting. Cairo, Egypt. October 1956. No. FAO/56/11/8537. p.10 Mimeo.
Blanco, M., Blanco, J.L. and Veiguinha, A.S. 1957. Obtención de híbridos de maiz de tallo azucarado, de doble aprovechamiento - grano y planta -y estudio comparativo, de su valor industrial, agricola y económico. Genet. Iber. 9:1-101.
250
Blanco, Μ., 1972 Estudio de la posibilidad de modificación en el contenido de azúcar y otros componentes del maiz para la mejora de su calidad. Tesis Doctoral. Universidad de Zaragoza.
Paez, Α.V., Helm, J.L., Zuber, M.S. 1969 Lysine content of "Opaque 2" maize kernels having different phenotypes. Crop Science, 9, 261 - 262.
Nelson, O.E. 1969- Genetic modification of protein quality in plants. Adv. Agron., 21, 171 - 194.
Morrison, F.B. 1949. Feeds and Feeding, Abridged VIII Ed. The Morrison Pub. Co., Ithaca, N.Y.
Animal Feed Science and Technology, 1(1976) 251-261 251 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
EFFECT OF AGRONOMIC FACTORS ON THE YIELD OF MAIZE AND ON ITS COMPOSITION IN RELATION TO ITS USE BY RUMINANTS
R.H. PHIPPS and R.F. VÎELLER National Institute for Research in Dairying, Reading, U.K.
ABSTRACT
The paper reviews work on how both air and soil temperatures can be modified by careful site selection and how this can, in the cooler northern regions of Europe, affect both yield and dry matter content of forage maize. Other important agronomic factors such as inorganic fertiliser, organic manure, plant density, genotype and date of harvest are discussed in relation to the quantity of forage produced. The effect of these factors on the development of plant components and their effect on chemically measured quality parameters are reviewed.
INTRODUCTION
In the cooler regions of Northern Europe there has been in recent years a rapid expansion in the area of forage maize (Bunting and Gunn, 1973). This revival of interest may be attributed to the advent of early maturing genotypes, selective herbicides and efficient harvesting machinery. The reasons for the farming community adopting forage maize are that it often outyields grass, has a high energy content and provides a valuable green feed during dry summers, its quality stays constant over a 5 to 6 week harvesting period and its reliability from year to year cannot be matched by other forage crops.
The present paper examines some of the agronomic factors affecting yield and discusses the effect of these on the quality of forage maize.
ENVIRONMENTAL FACTORS
Early maturing genotypes require approximately 660°C days to reach a dry matter content of 25% (Hough, 1975; Phipps et al., 1975). Hough (1975) stated that in order to exceed this
252 value in 9 out of 10 years in the UK a locality must receive on average 728°C days. These figures were used to define areas suitable for forage maize production: this area could be greatly increased by careful site selection, since well sheltered fields often receive a further 50°C days between May and October. Additional factors such as slope, aspect, cultivations and soil colour also influenced soil temperature and thus affected the rate of emergence, flowering date and final crop yields (Ludwig et al., 1957; Ludwig and Harper, 1958; Schmidt, 1973 and Phipps and Cockrane, 1975). The marked effect of site selection on final crop yields has been demonstrated clearly by Carr (1975). He noted that whole-crop dry matter yields increased from 9.5 t/ha on an exposed north facing chalk outcrop, to 16 t/ha on a well sheltered south facing brickearth. The crop at the well sheltered site also had a dry matter content 6% units higher than that on the exposed site. This would have allowed appreciably earlier harvesting of the crop, an important point in the cooler northern regions of Europe.
INORGANIC FERTILISER AND ORGANIC MANURE
In organic fertiliser Previous cropping, soil type, climate and organic manures
are all factors which affect the response to inorganic fertiliser.
In the USA and most of Europe, responses in forage maize dry matter yields have been recorded when up to 200 kg N/ha are applied (Kroth and Colyer, 1967; Doss et al·., 1970: Cummins, 1972; Allen et al., 1974; Maize Development Association, 1972, 1973, 1974) . The levels of phosphate and potash used were in few cases less than 100 kg/ha.
This situation differs markedly from that of the UK as only small increases in dry matter yield have been recorded when more than 80 kg N/ha have been used (Phipps and Pain, 1975; Pain et al., 1976). Responses to phosphate and potash have also been difficult to obtain. The smaller response obtained in the cooler northern maize growing areas may be due to their lower soil/root temperatures in the spring which could restrict nutrient uptake.
253 Organic manure
The escalating cost of inorganic fertiliser has resulted in renewed interest in the utilisation of organic manures. The application of 5070 t/ha of slurry has produced crops of comparable dry matter yield and dry matter content to those given inorganic fertiliser (Pain et al., 1976). However, high levels of slurry ( >105 t/ha) and inorganic nitrogen ( > 4 0 kg/ha) depressed yields mainly through the production of a less mature crop.
The use of slurry to grow forage maize not only doubled the energy output/input ratio but also reduced the problems of serious mineral imbalances and herbage rejection that occurred when it was applied to grassland (Pain and Phipps, 1975) . Table 1 shows that even very high rates of slurry had no marked effect on either digestibility or mineral composition of forage maize. TABLE 1 EFFECT OF SLURRY ON DIGESTIBILITY AND MINERAL COMPOSITION OF FORAGE MAIZE
% of DM Ν Ρ Κ Mg Ca Si02
Μη(ppm) Cu(ppm)
In vitro DÖMD
* Inorganic fertiliser
Control*
1.26 0.21 1.13 0.10 0.18 0.60 20.80 2.80 73
applied per ha
Level 125
1.22 0.20 1.90 0.08 0.26 1.30 25.00 2.20 68
134 kg N,
of slurry 250
1.34 0.22 1.45 0.07 0.21 1.30 35.OO 2.40 67
94 kg P205
(t/ha) 500
1.41 0.25 1.30 0.08 0.43 1.30 26.00 2.00 69
and 94 kg K20
PL/ANT DENSITY
In the UK the recommended plant density for forage maize is 10 to 15 plants/m^ and is based on the extensive work of Bunting (1971). This density ensures near maximum dry matter yields but ignores the fact that as density increases the proportion
254 of ear in the crop declines while that of the stem increases (Bunting and Willey, 1959; Rutger and Crowder, 1967; Thomson and Rogers, 1968; Cummins and Dobson, 1973; Allen et al., 1974 and Phipps, 1975). It also assumes no relationship between ear content and quality of the crop.
In the rest of Western Europe and the USA maximum dry matter yields are not achieved as plant density is restricted in order to obtain forage maize with a high proportion of ear (Bloc, 1971; Allen et al., 1974). This restriction in plant density and its subsequent sacrifice of dry matter yield has occurred because the quality of forage maize is often linked to ear and grain content. It is assumed that the best grain producing genotypes are also the most suitable for forage production (Chesneau, 1971; Demarquilly et al., 1971; Demarquilly, 1973). The outcome of this has been that most countries in Northern Europe assess genotypes solely on their grain producing ability, and that the UK is the exception in having a breeding programme for forage hybrids.
The link between forage quality and grain content is tenuous (Bunting and Gunn, 1973; Gunn, 1975) and may originate from Morrison (1956) who stated that the leaf, stem and ear had digestibility values of 61, 48, and 86% respectively. Thus it v/as thought that with the ear providing over 60% of the total digestible nutrients an increase in the proportion of ear and grain in the forage improved the feeding quality. These single component digestibility values do not take into account the translocation of nutrients from the stem to the ear. The same criticism can be levelled at trials comparing the quality of forages which had either been enhanced with additional ear material or had had the ear component removed (Andrieu and Demarquilly, 1974). Gunn (1975) in a recent review stated that "None of the experimental results provided convincing evidence to support the widely held belief that selection for high ear content will improve feeding quality". This sentiment is also shared by workers in Canada (Daynard and Hunter, 1975). The mineral content of maize is lov; but an increase in plant density from 4.9 to 16.7 plants/m2 had no practical effect on mineral content despite fairly large differences in grain component (Table 2).
255 TABLE 2 MINERAL CONTENT OF FORAGE MAIZE GROWN AT 4.9, 11.0 AND 16.7 PLANTS/m2
% in DM
Nitrogen Calcium Magnesium Phosphorus Potassium Sulphur mg/kg Zinc Manganese Copper Iron
4.9
1.31 0.24 0.13 0.20 1.80 0.11
25.00 26.30 3.90
114.30
Density (plants/m2) 11.0
1.26 0.23 0.14 0.18 1.67 0.11
33.30 24.20 3.70
112.30
16.7
1.25 0.23 0.14 0.17 1.72 0.11
23.50 22.30 3.60
110.80
Source: Phipps, 1975
Further work at the National Institute for Research in Dairying using a density-sensitive genotype (Anjou 210) planted at 5.0 and 15.0 plants/m^, produced forages of similar dry matter contents but containing 50 and 25% grain respectively (Phipps, 1976). Routine analyses showed the ΓΙΕ and DCP values of the high and lov; grain forages to be respectively 10.9 HJ/kg DM and 47g/kg DM and 10.6 MJ/kg DK'. and 56g/kg DM. These differences are small and it is conceivable that the levels of animal production achieved using these forages would also be similar. Although the energy values were similar, McAllan and Phipps (1976) showed that there were considerable differences in the carbohydrate components of the two crops (Table 3). These differences may be sufficiently large to produce . variation in animal performance.
The analyses in Table 3 show fundamental differences in the carbohydrate content of the crops which the DOMD values failed to indicate. Thus chemical analyses designed basically to measure the quality of grasses may have to be modified or altered when considering forage maize.
256 TABLE 3 WHOLE CROP CARBOHYDRATE CONTENT (g/kg DM). (PRELIMINARY RESULTS)
High grain Low grain
High grain Low grain
High grain Low grain
Sucrose 22.7 15.6
Mannose trace nil
Soluble sugars Fructose Glucose Mannose 18.1 22.0
Galactose 10.9 14.4
Starch 311.4 228.9
27.0 0.6 27.7 0.3
Hemicelluloses Arabinose
29.1 35.9
Total
Galactose 0.8 nil
Xylose 118.9 137.2
carbohydrates 689.5 631.7
Total 69.2 65.3
Total 158.9 187.5
GENOTYPE AND DATE OF HARVEST
In thé UK and France a large number of genotypes with different maturity ratings have been studied at various stages of development (Harris, 1965; Demarquilly et al., 1971). Analyses showed that the in vitro DOMD value of the whole crop was not markedly altered by either harvest date or genotype (Table 4 ) . TABLE 4 EFFECT OF HARVEST DATE AND GENOTYPE ON THE QUALITY OF FORAGE MAIZE
Caldera 20 18 21
LG 11 20 18 21
535 Aug Sept Oct
Aug Sept Oct
Whole crop % DOMD 72.1 72.4 71.1
72.8 70.4 69.2
% Ear 19 46 55
27 52 62
DM % 16 20 24
17 24 29
Source: Phipps, 1975
257
The constant whole crop DOf'-D value occurred because the dry matter yield and DOMD value of the leaf and stem declined, while the yield of ear increased and its D0I1D value remained constant (Tables 4 and 5). TABLE 5 QUALITY OF PLANT COMPONENTS
Caldera 535 20 Aug 18 Sept 21 Oct
DOMD (%) Leaf
65.6 63.6 60.7
Sten
' 71.3 67.8 61.2
Ear
82.3 79.1 79.4
Whole crop
72.1 72.4 71.1
Source: Phipps, 1975
The fall in DOMD value of the leaf and stem indicated that a substantial quantity of carbohydrates was translocated to the ear.
Wilkinson and Osbourn (1975) drew attention to the effect of dry matter content on silage fermentation characteristics. They considered that it was an important quality parameter, but pointed out that in the cooler northern regions of Europe it was difficult to achieve dry matter contents in excess of 25% at the end of the growing season. Kith dry matter contents below 25%, nutrients could be lost, effluent and the resultant danger of pollution could occur and intakes would be depressed (Fisher et al., 1968; Vérité et al., 1971). If, however, harvest date is delayed in order to obtain a higher dry matter content harvesting problems will be encountered and problems over future cropping patterns will be created. Thus, growers in these cooler northern regions must have early maturing genotypes with both high dry matter yields and high dry matter contents. Wilkinson and Osbourn (1975) considered the best way of achieving these objectives was to produce early maturing genotypes with a high ear content (starch) as there was a positive relationship between starch and dry matter content.
Comparisons between isogenic sterile and fertile plants
258 (Marten and Westerberg, 1972) , at densities commonly used for silage in northern Europe, showed little difference in dry matter yield, dry matter content, crude protein or in vitro DOKD. This led Bunting (1975) to state that "The importance attached to high grain content as an essential requirement for yield and quality in forage maize is exaggerated".
Gunn (1975) reviewed the literature on early and late maturing genotypes, normal and dwarf genotypes, tillered and non-tillered genotypes, and found no conclusive evidence to suggest that maximising the ear to stover ratio would enhance markedly the nutritive value of forage maize. However, a marked improvement in quality has been noted when the brown mid-rib mutant gene was incorporated in forage hybrids.
CONCLUSIONS
In the cooler northern regions dry matter yield and dry matter content can be increased greatly by careful site selection. In certain areas dry matter yield is sacrificed in order to produce forage with a high ear content. However, chemical analyses have not provided convincing evidence that a high ear content is mandatory for good quality forage. The effect of ear content must also be considered in relation to the effect of plant components on silage fermentation characteristics, volatile fatty acid production in the rumen and finally, but most important of all, on animal performance. These studies must be carried out with materials of similar dry matter content and must permit the normal movement of nutrients within the entire plant. The answer will have a profound effect on breeding programmes.
If the grain content is vital in producing good quality forage then genotypes which are not sensitive to density will be produced, thus coupling high dry matter yield and high grain content. However, if the grain content is not a vital component plant breeders would be able to use a much wider range of genetic material in the production of new forage maize genotypes.
259
REFERENCES
Allen, M., Ellzey, H.D., Nelson, B.D. and Montgomery, CR. 1974. Effect of nitrogen, population and hybrid on the yield and quality of irrigated corn for silage on Providence soil. Louisiana Agricultural Experimental Station, Bulletin No.676.
Andrieu, J. and Demarquilly, C. 1974. Chemical composition, digestibility and voluntary intake of fresh and ensiled male sterile maize. Annales de Zootechnie. 23, 1-25.
Bloc, D. 1971. La production du mais fourrage. Bulletin Technique d'Information No.264, 979-986.
Bunting, E.S. 1971. Plant density and yield of shoot dry material in maize in England. Journal of Agricultural Science, Cambridge, 77, 175-185.
Bunting, E.S. 1976. The question of grain content and forage quality in maize: comparisons between isogenic fertile and sterile plants. Journal of Agricultural Science, Cambridge, 85, 455-463.
Bunting, E.S. and Willey, L.A. 1959. The cultivation of maize for fodder and ensilage. 2. The effect of changes in plant density. Journal of Agricultural Science, Cambridge, 52, 313-319.
Bunting, E.S. and Gunn, R.E. 1973. Maize in Britain - a survey of research and breeding. Plant Breeding Institute. Annual Report.
Carr, M.K.U. 1975. The 1974 maize season in perspective. Maize Development Association Bulletin No.73.
Chesneau, J.C. 1971. Pour bien réussir la culture du mais-ensilage. Cultivar, No. 28, 1-5.
Cummins, D.G. 1972. Yield and quality of corn for silage grown under different fertiliser regimes. Georgia Agricultural Experimental Station, Bulletin No.105.
Cummins, D.G. and McCullough, M.E. 1971. Comparison of male sterile and male fertile corn for silage. Journal of Agronomy, 63, 46-47.
Cummins, D.G. and Dobson, J.W. 1973. Corn for silage as influenced by hybrid maturity, row spacing, plant population and climate. Journal of Agronomy, 65_, 240-243.
Daynard, T.B. and Hunter, R.B. 1975. Relationships among whole-plant moisture, grain moisture, dry matter yield and quality of whole plant corn silage. Canadian Journal of Plant Science, 55, 77-84
Demarquilly, C. 1973. Composition chimique, valeur nutritive et ingestibilité pour le ruminant des différentes formes de mais. L'Elevage, Numero hors série Le Mais 146-147
260
Demarquilly, C , Haurez, P., Journet, M., Lelong, C. and Malterre, C. 1971. Le ma'í.s plante entière: composition, valeur alimentaire, utilisation par les bovins. Bulletins Technique d'Information 264, 1OO1-1O10.
Doss, B.D., King, A. and Patterson, R.M. 1970. Yield components and water use by silage corn with irrigation, plastic mulch, nitrogen fertilisation and plant spacing. Journal of Agronomy, 62, 541-544.
Fisher, L.J., Logan, V.A., Donovan, L.S. and Carson, R.B. 1968, Factors influencing dry matter intake and utilisation of corn silage by lactating cows. Canadian Journal of Animal Science, 48, 207-214
Gunn, R.E. 1975. Breeding maize for forage production. Proceedings 8th Congress of Eucarpia, Versailles, 1975.
Hough, M.N. 1975 Mapping areas of Britain suitable for maize on the basis of temperature. Agricultural Development and Advisory Service, Quarterly Review, 18, 64-72.
Kroth, E.M. and Colyer, D. 1967 Response of corn to nitrogen fertilisation and plant population. Missouri Agricultural Experimental Station, Special Report 76.
Ludwig, J.W., Bunting, E.S. and Harper, J.L. 1957 The influence of environment on seed and seedling mortality. 3. The influence of aspect on maize germination. Journal of Ecology, 45, 205-224.
Ludwig, J.W. and Harper, J.L. 1958. The influence of environment on seed and seedling mortality. 8. The influence of soil colour. Journal of Ecology, 46, 381-389.
Maize Development Association 1972. Bulletin No. 46 Maize Development Association 1973. Bulletin No. 51 Maize Development Association 1974. Bulletin No. 69 Morrison, F.B. 1956 Feeds and Feeding. New York: Ithaca. McAllan, A.B. and Phipps, R.H. 1976 Unpublished data. Pain, B.F. and Phipps R.H. 1974 The effect of heavy dressings of slurry
on forage maize. Journal of the British Grassland Society, 29, 263-267.
Pain, B.F. and Phipps, R.H. 1974. The energy to grow maize. New Scientist, 66_, 394-396.
Pain, B.F., Phipps, R.H. and Richardson, S.J. 1976 The effects of inorganic nitrogen fertiliser and cattle slurry on forage maize. In press.
Phipps, R.H. 1976. Unpublished data.
261
Phipps, R.H. 1975. A note on the effect of genotype, density and row width on the yield and quality of forage maize. Journal of Agricultural Science, Cambridge, 85, 567-569.
Phipps, R.H., Fulford, Rosemary J. and Crofts, F.C. 1975. Relationships between the production of forage maize and accumulated temperature. Ontario Heat Units and solar radiation.. Agricultural Meteorology, 14, 385-397.
Phipps, R.H. and Cockrane, J. 1975. The production of forage maize and the effect of bitumen mulch on soil temperature. Agricultural Meteorology, 14_, 399-404.
Phipps, R.H. and Pain, B.F. 1975. Levels of fertiliser for forage maize. Agricultural Development and Advisory Service, Quarterly Review, 1£, 49-54.
Rutger, J.N. and Crowder, L.V. 1967. Effect of high plant density on silage and grain yields of six corn hybrids. Crop Science, T_, 182-184.
Schmidt, 0. (1973) The effect of bitumen emulsions on soil temperature and plant yield. Herbage Abstracts, 44_, 1539.
Thomson, A.J. and Rogers, H.H. 1968. Yield and quality components in maize grown for silage. Journal of Agricultural Science, Cambridge, 71, 393-403.
M
Vérité, R., Hoden, A. and Journet, M. 1971. Avec un bon ensilage de mais les vaches laitières consomment moins d'aliment concentré. L'Elevage, numero hors série Le Mais, 157-163.
Wilkinson, J.M. and Osbourn, D.F. 1975. Objectives in breeding forage maize for improved nutritive value. Proceedings 8th Congress of Eucarpia, Versailles, 1975.
Animal Feed Science and Technology. 1 (1976) 263-271 263
Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
AGRONOMIC FACTORS AFFECTING THE GROWTH AND COMPOSITION OF THE MAIZE PLANT
J. ANDRIEU
Institut National de la Recherche Agronomique, Centre de Recherches Zootechniques et Vétérinaires, Theix, 63110 Beaumont, France.
INTRODUCTION
As French results during the last five years have shown very clearly, the dry matter yield of forage maize and the composition of the plant at harvest can be very variable. In France, early varieties, bred for grain yield and often with a common ancestor, INRA 258, are generally used for forage maize production. In these conditions, it could be suggested that the great variability in the results obtained was due more to environmental conditions than to the varieties used. In the light of results both in the bibliography and those obtained in France by the Institut National de la Recherche Agronomique (INRA), by the Institut Technique des Céréales et des Fourrages (ITCF) and by the Association Générale des Producteurs de Mais (AGPM), we shall examine the importance of different environmental factors on plant productivity and composition. Since the subject is very wide, we shall consider only early and very early varieties (FAO index below 300) during the stage of growth when they can be ensiled, that is from the late milk stage (about 25% of. dry matter in the plant) to the early glaze stage (about 35% dry matter).
INFLUENCE OF AGRONOMIC TECHNIQUES
Plant density From many trials in different parts of the world (Crossman,
1968; Eddowes, 1969; Rutger and Crowder, 1967), it appears that the dry matter production of the whole plant increases up to a certain density and levels off. Maximum production is attained at varying densities, but generally increases with favourable conditions and early date of harvest (when the effects of lodging and of competition between plants are less noticeable).
TABLE 1 EFFECT OF PLANT DENSITY ON DRY MATTER YIELDS OF FORAGE MAIZE (ITCF and AGPM trials)
YEAR
REGION
Earliness group
Plant density (thousands/ha )
Number of trials
Dry matter content (%)
Dry matter yield (t/ha)
Ears in total dry matter (%)*
1970 to 1972
West - East -North - Centre
Groups 0 and 1
85.7 100.4
50
30.2
14.5
-
29.8
15.1
-
Centre
Beginning of Group 1
74.1 88.2
14
35o6
14.4
-
35.2
14.7
-
1 9 7 4
All regions
Group 1
74.1 93.4 113.5 130.1.
12
27.4
11.0
55.0
26.3
11.8
50.5
26.3
12.4
49.5
25.6
12.1
46.0
1 9 7 5
Cantal - Cote du Nord - Vendée
Beginning of Group 1
74.2 89.8 112.5 125,2
16
31.7
12.5
64.5
30.5
12.8
62.5
29.7
13.3
59.0
29.1
13.6
57.5
"ears" - grain, rachis, husks and ear shank.
265 In addition, it is generally considered that a maize destined for silage can be sown more densely than grain maize.
Trials carried out by the Technical Institutes (ITCF and AGPM; Table 1) indicate that the optimum density for the harvest of plants containing about 30% dry matter (late dough, early glaze, stage) is 15 20% greater than that considered optimum for grain production. In French conditions densities of 90 000 110 000 plants/ha are recommended for very early varieties and 75 000 90 000 plants/ha for early varieties. Increase in density results in an average increase of 0.5 t of DM/ha (range, from O 1.5 t) and in a slight reduction in percentage of ear (with its husks) in the dry matter (2.5 percentage units on average). Similarly, trials carried out in our laboratory (Andrieu and Demarquilly, 1974) show (Table 2) that the reductions in ash, crude fibre and more especially in crude protein content associated with increasing plant density are small. » Fertilisers
The influence of level of fertiliser on the production of forage maize has not been the object of any systematic studies in France. Most often fertiliser rates are comparable with those advised for grain maize: 150 units of Ρ,Ο and K_0 and 100 150 units of N/ha depending on whether or not manure is provided.
As Harshbarger et al. (1954) showed, nitrogen fertilisation does not alter the morphological composition of the plant (notably the percentage of ear in the whole plant dry matter) at least, under good environmental conditions. In contrast, it generally increases the crude protein content of the plant, although to a variable extent ( 7 86%) (Alexander et al. , 1963; Jahn, 1961; Nandpuri, 1964). Essentially, this increase results from an increase in the crude protein content of stems and leaves (Genter,1960). In our trials (Andrieu and Demarquilly, 1974), the crude protein content of maize which has received 100 150 units N/ha, varies from 7.5 10.0% of the dry matter but can fall to 5% in the case of maize suffering from excess soil moisture at emergence and thereafter from a considerable summer drought (Table 2).
TABLE 2 INFLUENCE OF PLANT DENSITY ON FORAGE MAIZE COMPOSITION
YEAR
Place
Plant density (thousands/ha)
Number of comparisons
Harvest date (1)
DM content (%)
COMPOSITION (% DM)
Ash
Crude protein
Crude fibre
1 9 7 0
MONTOLDRE (2) (4)
62.2
3
58 + 3
29.3 + 1.1
5.2 + 0.3
5.5 + 0.7
22.0 + 1.4
79.9
3
57 + 5
27.6 + 1.0
6.0 + o;3
5.4 + 0.3
21.7 + 1.2
MALINTRAT (2)
74.5
3
4 1 + 3
32.1 + 1.6
5.8 + 0.4
9.7 + 0.2
17.7 + 1.6
93.7
3
43 + 2
31.4 + 2.2
6.3 + 0.6
9.3 + 0.2
19.6 + 1.4
1 9 7 3
CHANONAT (3)
86.6
8
44 + 4
36.8 + 4.0
5.6 + 0.3
3.0 + 0.5
21.0 + 0.8
109.6
8
4 5 + 4
36.9 + 4.2
5.9 + 0.3
8.0 + 0.6
22.5 + 1.8
(1) Harvest date expressed as days after female flowering; (2) Composition of silage; (3) Composition at ensiling; (4) Drought-stricken maize.
267 Sowing date
It is well known that the influence of date of sowing on the production and composition of forage maize can be very variable, depending on the earliness of the variety and environmental conditions. It also depends considerably on the date of harvest when the environment is favourable (Table 3, 1st and 2nd sowing dates). In regions of France where only early or very early varieties will reach 30% dry matter (north and west of France), the trials carried out by AGPM (1972 - 75) show that for a given harvest date (imposed by climatic conditions at the end of the growing season), later sowing gives poorer results than earlier sowing, both in terms of dry matter production and percentage of ear in the plant. With later sowing, temperatures are too low during the phase of grain maturation and limit grain development (Table 3, 3rd sowing date). Thus sowing as early as possible, about 15th April, is advised.
In regions where late varieties reach 30% dry matter (south west of France, for example), the influence of sowing date has been little studied with early varieties, although these may provide a useful catch crop. According to work by Kiesselbach (1950) and Van Dobben (1962) later sowing would give taller plants with a reduced percentage of ear, possibly owing to longer day length and higher daily temperatures during the first few weeks after emergence.
INFLUENCE OF CLIMATIC FACTORS
As the results we have obtained with INRA 258 'indicate (Table 4), climatic conditions are by far the most important factors affecting forage maize production and composition. In good growing conditions early varieties harvested at a satisfactory dry matter content of 30 - 35% (early glaze stage) give production levels of 12 - 14 t/ha of dry matter of which 60 -65% is in the ear and husk.
In contrast, the trials we carried out in 1970 at Montoldre (Table 4) illustrate the very unfavourable effect of drought during flowering in maize crops grown on a poorly drained clay soil. Similarly, many authors have shown the great importance of temperature during and after flowering on grain development
TABLE 3 EFFECT OF DATE OF SOWING ON COMPOSITION AND YIELD OF FORAGE MAIZE (Trial carried out by AGPM at Boigneville - 1972Ί' - Average of three varieties)
Date of sowing
Date of harvest
15 Sept 26 Sept 5 Oct 17 Oct 27 Oct 8 Nov
Dry matter content (%)
25 April
23.9 27.4 31.0 35.6 36.8 41.5
19 May
20.3 22.8 25.7 30.7 34.2 36.0
12 June
15.6 17.7 19.6 22.6 23.9 23.4
Dry matter yields (t/ha)
25 April
13.4 13.9 15.5 14.8 14.5 14.2
19 May
12.2 13.3 13.7 14.8 14.2 13.9
12 June
9.4 10.5 12.2 13.3 12.9 11.3
Contribution of ear in total dry matter
(%)
25 April
55.9 58.4 60.6 62.4 63.4 67.3
19 May
47.8 54.0 56.6 60.6 62.7 65.2
12 June
28.9 36.9 43.5 48.1 48.9 52.2
(1) The seasons during which this experiment was in progress were highly favourable.
TABLE 4 EFFECT OF YEAR AND CLIMATIC FACTORS ON THE COMPOSITION AND YIELD OF VARIETY INRA 258 (2)
Year
1968 1969 1969 1970 1970 1972 1972
1973
Seasons
Favourable Favourable Favourable Drought at flowering Favourable Low temperature Low temperature and frost (1) Drought at dough stage
Plant density (thousands /ha)
71 50 65 75 70 104
104 84
Dates of
sowing
19 April 15 May 13 May 4 May 5 May
22 May
22 May 22 May
Days after flowering (3)
65 61 54 42 59 66
85 49
Composition of forage at ensiling
Ears (% of DM)
65.0 68.5 66.6 56.3 61.0 48.0
52.9 62.5
Dry matter content (%)
33.0 33.7 30.8 29.9 33.9 21.2
23.6 41.8
Ash (% of DM)
4.7 4.1 5.0 6.3 5.7 6.1
6.2 5.7
Crude protein (% of DM)
6.3 7.6 6.8 5.3
10.1 10.2
9.1 7.6
Crude fibre (% of DM)
17.3 17.8 17.7 19.6 18.5 20.5
21.5 21.0
Starch (% of DM)
26.6 30.0 28.9 15.3 22.5 5.9
12.0 23.5
Yields (t/ha)
-9.9 10.7 6.0 14.2 9.8
10.5 10.8
(1) Leaves were burnt by frost between two harvest dates. (2) All these trials have been carried out in the Massif-Central n.ear Clermont-Ferrand. (3) Harvest date expressed as days after female flowering.
270 and thus on the increase of dry matter content in the ear and in the whole plant. Two years of trials with the variety INRA 260 by Bloc and Gouet (1973) have shown that a close correlation exists between the sum of the average daily temperature after flowering (X, base 7 C) and the dry matter content of the ear (Y ) and of the plant (Y ):
Υχ = 0.26 + 0.073 X ; r = 0.96 Y2 = 4.88 + 0.045 X ; r = 0.95
According to these results, about 560°C (calculated with a base of 7°C) after the point of female flowering (silking) is necessary for development to 30% dry matter in the plant. In Northern France where accumulated temperatures rarely reach 450°C, the very early varieties, although harvested long after flowering, give only 8 10 t DM/ha since their grain is not developed. Their case is well illustrated by the trial we carried out in 1972, a particularly cold year in the MassifCentral (Table 4).
CONCLUSION
During recent years the area under forage maize cultivation in France and in Europe as a whole, has increased spectacularly. The principal reasons for this extension are the following:
a) the maize crop can be completely mechanised and with the use of hybrid varieties, is capable of giving high yields, b) there are numerous possibilities for using maize in animal feeds, particularly for ruminants. The variation in potential utilisation method is much appreciated by farmers. However, results obtained during the last five years show
that yield amd plant composition can be very variable, particularly in relation to climatic conditions. This is in part due to an extension of the crop on to hill land and in to more northern zones. Knowledge of accumulated temperatures, of the frequency of early frost and of the incidence of drought appear necessary prerequisites to the introduction of the crop into a given region· This is especially important since, as we shall show in another publication (Andrieu, 1976), the nutritive value of silage may be low in unfavourable climatic conditions.
271
REFERENCES
Alexander, R.A., Hentges, J.F., Robertson, W.K., Barden, G.A., Mc Call, J.T. 1963 Composition and digestibility of corn as affected by fertilizer
rate and plant population. J. Anim. Sci., 22, 5-8. Andrieu J. and Demarquilly, C., 1974 Valeur alimentaire du mais-fourrage
11 - Influence du stade de végétation, de la variété, du peuplement, de l'enrichissement en épis et de l'addition d'urée sur la digestibilité et l'ingestibilité de l'ensilage de maïs. Ann. Zootech., 23, 1 - 25.
Bloc, D. and Gouet, J.P. 1973 Influence des sommes de température sur la maturité du maïs. Docum. ITCF - AGPM.
Crossman, G. 1968 Plant density and dry matter production in maize. Field Crop Abstr., 21, p. 116.
Eddowes, M. 1969 Physiological studies of competition in zea mays 1, 11, 111. J. agrie. Sci-, Camb., 72, 185 - 215.
Genter, C.F. 1960 Corn and other crops for silage in Virginia. Virginia Agr. Expt. Sta., Bull. 516.
Harshbarger, K.E., Nevens, W.B., Touchberry, R.W., Lang, A.L. and Dungan, G.H. 1954 The yield and protein content of silage corn as influenced by fertilization. J. Dairy Sci., 37, 976 - 981.
Jahn, S.V. 1961 Feeding value of maize for silage treated with different amounts of fertilizer. Herbage Abstracts, 34, 233.
Kiesselbach, T.A. 1950 Progressive development and seasonal variations in the corn crop. Nebraska Agr. Exp. Sta. Res. Bull., 24, 2 - 49.
Nandpuri, K.S. 1964 Effect of different plant populations and nitrogen levels on the yield and protein content of corn silage. Herbage Abstracts, 34, 13.
Rutger, J.N. and Crowder, L.V. 1967 Effect of population and row width on corn silage yields. Agron. J., 59, 475 - 476.
Van Dobben, W.H. 1962 Influence of temperature and light conditions on dry matter distribution, development rate and yield in arable crops. Neth. J. agrie. Sci., 10, 377 - 389.
Compte rendus d'expérimentation ITCF et AGPM, années 1972, 1974 et 1975. Comparaisons pluriannuelles des caractéristiques fourragères des variétés
de maïs. Mise à jour 1972. ITCF - AGPM. Andrieu, J. 1976 Factors influencing the composition and the nutritive
value of ensiled whole crop maize. In: J.C. Tayler and J.M. Wilkinson (Editors), The Maize Crop as a Basic Feed for Beef Production. Animal Feed Science and Technology.
Animal Feed Science and Technology, 1 ( 1976) 273 -286 273 Elsevier Scientific Publishing Company. Amsterdam - Printed in The Netherlands
DISCUSSION ON SESSION 2
R.J. Wilkins UK
We have 35 minutes for discussion on these five papers. There has been much material presented that is of extreme interest to us and I am sure that each one of these papers is really worthy of the entire discussion period that we have. Let me pick out two or three themes or aspects that came up on more than one occasion before making the discussion period open.
Firstly, there was a tremendous accent in all the contributions we had on using the whole crop. This was the case in the contribution from Yugoslavia and from Spain, countries which, we were told earlier today,have been primarily growing maize as a grain crop. So I think we would see, as Savio' pointed out in his paper, "What is the point of growing it and then leaving 40% or so of the potential energy, dry matter that you have produced, in the field"? So, our speakers on crop production here were very concerned with the ways in which we could utilise all that they could grow. We had our eyes opened by Professor Blanco, to the possibility of mechanical fractionation of the stover of the crop. Later on in the conference we shall be coming back to these themes as to how, as nutritionists, we can use what is grown. Possibilities for alkali treatment and upgrading the stover, will, I am sure, feature in our later discussion this week. So, we are wanting to use as much of the crop as we can.
A second aspect is one of climate in relation to yield and quality. Here, not unnaturally, there were different problems highlighted as being the most important by our different speakers. We heard in Savie's and Monteagudo's papers about problems of drought stress and tolerance, moisture relations, in relation to growth. We did not really hear what the plant breeders thought they could do about improving the performance of maize under very dry conditions although there were indications given from Savie that we really needed 250 - 350 mm of rain during the growing season. Ïhere was a suggestion from Spain that we could use a tensiometer to help us plan when we could inject more water into the system and therefore make
274 more efficient use of water in growing maize. These are aspects that we should come back to in discussion.
The speakers from further north in Europe were concerned more with growth at low temperatures and speed to ripening and maturation of the crop. We did not really hear of any progress being made or any activity in trying to identify maize genotypes that would grow at lower temperatures. This is something that we might, again, want to explore in this discussion. We did hear about the ways in which we could help in identifying areas suitable for growing maize and in more than one paper we were talking about accumulated temperatures, in Centigrade degrees, I believe, above a 70° minimum as a climatic index for growing maize. This is something on which there has been quite a lot of research activity and we may also want to spend more time thinking about growth in the early part of the life of the maize crop. One aspect that we have not begun to discuss is the relation between climate and the composition of the crop. Phipps was showing slides with in vitro "digestible organic matter in the DM", a very clumsy expression which we use in the UK a lot, values of 70 - 72. This means an organic matter digestibility of 75 for a whole crop of maize. We have felt for quite a long time that the digestibility of our whole crops, despite having a rather low grain content, tends to be higher than those grown in much of the United States and in southern Europe and it would be helpful to hear, particularly from people in southern Europe, as to what figure we are talking about for digestibility of whole crops of maize.
Turning now to other aspects of agronomy, the two things that we have clearly, and not surprisingly, spent time on - the questions of plant density and response to nitrogen fertiliser. In relation to plant density there does not really seem to have been any major agreement; we say that if we have got more water available for growth we can increase the plant population, if we are going to utilise the crop as a whole crop for silage rather than for grain, we will further increase level of population, and the highest figures that we were talking about were something in the order of 100 000 plants per ha. We may perhaps note that if we are saying that for growing for silage we increase plant population, we know that we are then
275 going to reduce the ear content, and this is perhaps implying some acceptance of a point that maximisation of grain content is not of the first importance in relation to silage crops.
Nitrogen fertilisers - there was an interesting point brought up by Savie this morning in talking about nitrogen fertiliser application with plants at the six to nine weeks stage. He was saying that nitrogen fertilising policy was being simplified, perhaps, in Yugoslavia; Phipps talked about the very low nitrogen fertiliser responses that have been obtained in Britain - they were really not much different from the figures that Andrieu suggested. So I would appreciate comments in a few minutes about the pattern of nitrogen fertiliser application in relation to the growth of maize. This is just trying to bring your minds back to points that we had brought to our attention in these papers.
I would now like to make the discussion open but I will suggest that we should be concerned here with climate, agronomy, genotypes in relation to yield and chemical and morphological composition (perhaps in vitro digestibility) but questions on the overall animal productive value of the crop and aspects specifically related to conservation will be better dealt with in later sessions.
D. O o s t e n d o r p Netherlands
May I comment on the question of nitrogen fertilisation and fertilisation in general in maize, the figures mentioned by Dr. Phipps, about 80kg of nitrogen, are very low by our standards and ideals since in relation to yields and content of nitrogen a good crop of maize in Holland requires about 180 - 220 kg of N/ha and the same refers to the UK. It is very important to take account of the soil content of nitrogen in relation to the amount of fertiliser that is needed. It is also important, of course, to consider the amount of other nutrients that are given in the form of slurry. In Holland for instance, for each tonne of slurry we calculate 2 kg of N, 2 kg of Ρ2°5
a n d 5 k9 of K_0,
so there are more factors involved than just the level of fertiliser.
276 R.J. Wilkins
Yes, do you have any observations on late application of fertiliser nitrogen, that is, summer applications to the growing crop in the way that Savie was describing?
D. Oostendorp
Yes, this amount, say 200 - 225 kg N/ha, is often given in two dressings.
R.J. Wilkins
The point made there is a very good one, that if you have got a crop - and in Britain we will be taking out at least 150 kg of nitrogen per ha with the crop - then that nitrogen has got to be supplied from somewhere. Do we have any more observations in relation to nitrogen fertiliser of the crop? Are there any countries where it is common to apply 200 kg of nitrogen to maize?
D. Lanari Italy
I am not an agronomist, but I know that in our country, to produce maize either for grain or silage production, we use a very high amount of nitrogen. We use up to 2 50 or 300 kg of nitrogen, this is done on fields where maize is cultivated year after year for up to 5, 6, and 7 years.
R.J. Wilkins
That's a situation where your soil nitrogen supply would be very small.
D. Lanari
Yes, so. I am a bit surprised that the figures mentioned are not higher.
277 R.J. Wilkins
Dr. Savie, I believe you referred to about 18Ö kg or something of that order?
R. S a v i e Yugoslavia
Altogether we supply here for good high mature yield, about 300 kg of fertiliser nutrients. The ratio of N:P:K is 1.0:0.8: 0.6. that means 120 - 140 kg N/ha.
R.J. Wilkins
Just a clarification of that; by nutrients you mean P 30_ and K 20?
Yes.
R.H. Phipps UK
I will agree that there are obviously major differences in the fertiliser recommendations and the slide I showed was a summary of 17 separate fertiliser trials carried out in the UK from 1958 - 1974. I think only one had been published and I think the reason why the others had not been published is that the authors were expecting a big response to nitrogen under UK conditions - they did not get it and they thought there was something wrong with the experiment. However, when you add 17 experiments together and still come up with the same result then I think there are obviously factors which are at variance between the UK and other regions. Possibly one explanation maybe our lower soil temperatures in the spring which could restrict nutrient uptake of the NPK during the early stages of development with the maize crop. The other, possibly, may be that the inherent fertility of the UK soils may be higher but in one particular field which has grown 12 consecutive crops of barley, we could only show a response of up to 80 kg of nitrogen per ha when we grew maize. We just cannot get
278
experimental evidence to justify using more than about 80 kg of nitrogen per ha.
R.J. Wilkins
I think Oostendorp was right in drawing our attention to the balance between nitrogen in the crop and the total supply.
R.H. Phipps
Oh indeed, mineralisation of nitrogen from our soils would contribute up to 50 kg of nitrogen per ha which takes that up to a total of 130.
R.J. Wilkins
Thank you. Let us move on from nitrogen to another major input affecting the crop. This is water - irrigation. When you were talking about a tensiometer, were you thinking about an experimental technique or something that could be used practically?
A. Monteagudo Spain
Nobody uses it practically but, sometimes, we need the tensiometer for experiments; it depends on the class of soil.
R.J. Wilkins
In countries where you have big soil water deficits and you have irrigation available is the financial return for using water on maize very competitive with that from other crops? What is the situation in Spain and Yugoslavia?
A. Monteagudo
The use of water can be very complicated because in Spain for some periods of each year we need the water for drinking. One possibility is to move the time of sowing in relation to
279 the rainy period. We need more water. It is a question whether we have more déficiences in water with two crops than one crop and whether other crops can be used.
R.J. Wilkins
You suggest that growing other crops such as sorghum could be a solution. Is there any available variation within maize in relation to ability to extract water from the soil or to tolerate short periods of water stress?
J.L. Blanco Spain
We have no real figures about the efficiency of water utilisation, but we know that there is some interaction with the different factors involved. There are some places, for example, in the south, where the temperatures are very, very high and the efficiency of water use varies very much. This interaction between the different factors; nitrogen fertiliser, water,the date of planting, the number of plants per ha, and so on, depends very much on the genotypes Many of the genotypes react completely differently in efficiency of use of nitrogen, water and temperature and sometimes the reactions are quite different depending on the origin of the hybrid. When we changed the date of planting for the American hybrid, the reaction in production was very small. With the Spanish hybrid, we get a tremendous response to every planting. Sometimes it is 50% of the yield. The same happens with the number of plants per ha and with nitrogen. For example, in general the American hybrids produce only an extra 200 kg per ha to 400 kg per ha with a change of 20% in nutrition. With some Spanish hybrids the reaction is 60% plus. All these factors together make a tremendous difference and we cannot speak about the efficiency of the use of nitrogen or of temperature or water, we need to think of the efficiency of one hybrid, to produce the one with an optimum combination of factors. This is why it is very difficult to discuss this question. In other words, there is a very complicated interaction, a multi-factor situation with the reaction of any factor in relation to the others for each
280 type of hybrid.
R.J. Wilkins
So you would suggest that there is tremendous opportunity for fitting a genotype to a particular environment.
C. Lelong France
I am surprised that Phipps recommends sowing 150 000 plants per ha in early hybrids for silage production and ask why he suggests this, because one factor he did not mention was the lower content of DM as the density increases, and to make silage the DM content is an important limiting factor.
R.H. Phipps
The range of densities recommended for silage in the UK varies between 100 000 to 110 000 and when we go to the wetter western areas may be as high as 150 000. These densities are recommended in order to achieve near maximum DM production. The work at Cambridge has, in fact, shown that in that range, averaging 130 000 plants per ha, with the majority of hybrids used in the UK there is only a 1% or 2% unit difference in the DM content of our crops - no more.
M. Strickland UK
My question follows on from the previous one. Our problem on the heavy soil near Cambridge is really starting the crop off in the spring. We have heavy soil which takes a lot of time to warm up and we often· get disappointing results simply because the crop does not get started. I am wondering whether there is an opportunity for selecting genotypes that would, in fact, tolerate colder conditions in order to get a better start and a longer growing season in which to produce more yield.
281
E. Zimmer Hest Germany
I would like to ask Dr. Phipps a question. Can you give me the DM content, the figures, for 100 000 - 110 000 and 150 000 and below, let me say, 70 000 and 80 000 plants per ha, as we do in central Europe, the DM content of the whole crop?
R.H. Phipps
I cannot give you the exact figures at the moment, but I can give you several papers in which the DM content of the crops at a range of plant densities, is given. We find little difference in the DM content of our crops in that sort of range.
E. Ζ immer
What, approximately, is the range? In the morning we had figures from northern Germany, and Dr. Oostendorp from the Netherlands agreed, showing that we can reach 24% or 25% of DM in the whole crop. In going south, of course, we increase our DM content. I would like to hear the figures from the UK. Is it below 20%?
R.H. Phipps
No. The majority of crops harvested in the UK are in the region of 25% DM. In very bad years people have harvested at as low as 20%, but by and large 25% DM is what is achieved.
R.J. Wilkins
I think this is something in which there is tremendous variation from year to year in what is happening. We will have had some years recently which have been very cool during the autumn period and then, at any one date, there would have been very little difference between densities but all around the 20% DM mark. If we have a better year, rather more like those that you have in Braunschweig, at any date there would be a difference but if we are taking 25% DM for our guideline
282
figure, which has been the figure which we have tended to use in the UK, then the effects of differences in density would be some spacing out in the date of harvesting, perhaps with three weeks or so between the highest and the lowest density.
R.H. Phipps
Much, much less than that.
K.G. Mølle Denmark
I would like to put a question to anybody who would like to give a reply. Is it advisable to place phosphorus and nitrogen at the moment of sowing? In Denmark we have read about experiments indicating that if you place nitrogen/phosphorous fertiliser 5 cm or so from the maize seed when sowing you get better resistance to low temperatures in spring and early summer and you get good development; in this way a maize crop may have a higher DM content in September. Should this technique be recommended for the cooler climates, or is it a generally advisable technique?
R.J. Wilkins
I am looking for offers to respond to that question.
Normally, here in northern Yugoslavia we use phosphorus and potassium, before ploughing or at the latest opportunity before planting but not for the reasons you mention. This is only to spare transport and to spare time applying this fertiliser but whether maize will ripen better I do not know. For us it is just for economic reasons and we try to give the fertiliser twice.
R.J. Wilkins
Any comments on placement of fertiliser?
283
D. Oostendorp
The practice in Holland is to give the phosphate as a row application together with sodium at 5 cm. We think that is a good practice for the cold regions.
R.J. Wilkins
We have not managed to flush out any hard experimental data on this.
J.C. Tavler UK
There is another subject I would like to bring in at the request of a colleague, Mr. Gillot, who looks after the protein programme of the Commission. He would like to know whether any maize producers are interested in growing soya together with maize for silage and he also raises the question whether there is any interest, where the climate is suitable for two crops a year, in applying the American practice of growing a maize crop to be harvested in the immature stage for silage, followed by soya which is then harvested for grain.
E. 2 immer
Double cropping is s common practice in Germany, but it depends on the water availability. We normally use rye, or wheat, and then have the second crop as maize. If water is available then the double crop yield is more than the single yield of maize but very often the rye uses the water and the maize has insufficient water and then the total yield is no greater with double cropping. So, only in particular regions is it recommended.
R.J. Wilkins
I believe the practice of mixing high protein crops with maize has been something that in mid-European countries, certainly a few years back, was quite common.
284 R. Savie
Soya production in our country, especially in this part is uncertain. We try to mix for silage, but only for silage.
R.J. Wilkins
We might think of legumes other than soya, that might be more important to us.
K.G. Mølle
Concerning the double crop system, I can say that we have tried in Denmark, only a few times, to grow maize, not with soya but another sort of bean, but I reckoned there were no advantages in doing this. The maize grew poorer than without the bean and the bean itself did not increase the total yield so much that there was any interest, but that was under Danish conditions.
R.J. Wilkins
Our philosophy in the UK is generally along those lines, that we would do better to grow the crops separately and mix at the time of feeding rather than compromise the agronomy and cultivation of each individual crop.
C. Lelong
We heard in France of German maize forages that were rich in protein; is it true or not?
M. Zscheischler W, Pt Gi many
In Germany, we now have two varieties but they are not registered; they are in the second year of proving and we do not know the details.
285
R.J. Wilkins
This is grain maize?
M. Zscheischler
No, for forage. Professor Polimer at Hohenheim is breeding two varieties but nobody knows the value and there are even different figures about the difference in protein content at present. Last year was the first, and they were tested on about five sites in Germany but so far there are no official figures available.
Ch. V. Boucqué Belgium
Several speakers have mentioned the FAO Standards or Index. Can somebody explain that?
R.J. Wilkins
It is an index which is not used very widely in Britain and I was very impressed at how several authors here could use it, and I am sure we do want standards to help us discuss variety types.
M. Zscheischler
I want to explain it. In 1954 at Belgrade, there was a proposal to bring in these FAO Standards. These Standards are the same as in Wisconsin; we had check varieties like Wisconsin 255, Wisconsin 355A and Wisconsin 400, and so on. These are relative numbers; they have nothing to do with days from sowing to ripening. They go from 100 - 1 000, even 1 200. So we have a relative measurement for getting in a scale these different varieties. As far as Germany is concerned, we can only use, for grain, varieties between 190, or roughly 200, and 300. We have heard from Professor Savie1 that he has varieties of 600 and even later. In Georgia in the US they even have varieties of 1 000 and 1 200. Under our conditions in Germany
286 we feel that between 50 numbers there is a difference of about 6 - 8 days and also 6 - 8% DM content in the grain. However, there is quite a big difference in the different countries.
R.J. Wilkins
Also, if you have a new variety this is grown in particular environments in relation to standard varieties and then it is given a rating on this FAO scale?
J.M. Wilkinson UK
Mr. Lelong's paper gives some of the common European varieties along with their FAO Index numbers. One can get some idea from that.
R.J. Wilkins
Thank you all for keeping with us during this session and helping this discussion. In closing the session, I would like to thank again the five speakers who contributed.
287
SESSION III
EFFICIENCY OF HARVESTING AND CONSERVATION
Maximising nutrients harvested and made available to livestock as fresh, dried or ensiled whole crop or as ears or grain. Effects of date of harvest, dry matter content, additives, method of preservation, variety and chopping treatments on crop composition, fermentation of silage and wastage during storage and feeding. Methods of reducing wastage.
Animal Feed Science and Technology. 1 (1976) 289-299 2 8 9 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
EFFICIENCY OF HARVESTING AND CONSERVATION
E. ZIMMER Institut für Grünlandwirtschaft, Futterbau und Futterkonservierung der Forschungsanstalt für Landwirtschaft, D 3300 Braunschweig, Bundesallee 50, GFR.
ABSTRACT
Green maize (10 - 16% DM) contains about 550 - 590 g SE/kg DM; the whole crop cut at the milk to dough stage (20 - 30% DM) contains about 620 - 650 g SE/kg DM. Within each of these feeds nutritive value is largely independent of harvest time.
Genotype does not affect the nutritive value in general, and fertilisation will affect yield much more than nutritive value.
Specific, unavoidable losses resulting from the ensiling process are calculated to give a reduction of 30 - 50 g SE/kg DM. Losses reach 10 - 15%. Secondary fermentation, as well as aerobic processes caused by sub-optimal technology, will incur an additional reduction of 20 - 40 g SE/kg DM. Unstable silages will have a reduction of 10 - 30 g SE/kg DM from heating.
NPN additives in general improve the protein-energy ratio, 'as well as fermentation. There is a specific effect on stability The effects of late harvest and the nutritive value of sun-dried maize straw are discussed.
QUALITY OF FRESH MATERIAL
Stage of maturity Between milk and late dough stage, the nutrient concentration
shows only small variation and is independent of date of harvest (Table 1). Nevertheless, dry-matter content below 25%. means seepage problems and increasing risk of a lactic type of fermentation.
Energy content lies between 620 and 650 g SE/kg DM and digestible organic matter is 73 - 75%.
For so-called "green maize", made up mostly or exclusively of vegetative material, nutritive value ranges between 550 and 590 g SE/kg DM and DM content is below 18%.
TABLE 1 COEFFICIENT OF VARIATION FOR PARAMETERS OF NUTRITIVE VALUE
Author
Green material Demarquilly Schneeberger Thomson Cummins Davis and Bowden Giardini Rosenstiel Maize silage Dijkstra Schneeberger Gross
Country
France Switzerland UK USA Canada Italy FRG
Netherlands Switzerland FRG
Year
1969 1971 1968 1970 1968 1963 1962
1960 1968 1970
Parameter
DOM* DOM DOM in vitro DOM in vitro digestible energy UF/DM SE/DM
SE/DM SE/DM SE/DM
Stage of maturity
milk· - dough bloom - mature
late milk - mature milk - dough beg.milk - late dough milk - dough
DM (%)
22 - 30 -
18 - 35 25 - 37 16 - 26 19 - 38 20 - 30
1 3 - 2 0 16 - 35 12 - 31
Interval (d)
?
-70 -60 -30 -55 -35 -40
---
Coefficient of variation (%)
0.9 1.0 2.7 3.9 2.2 3.2 1.7
9.7 9.7 5.6
* Digestible organic matter
291
Calculation of energy content can be done by regression formulae, based on the parameter crude fibre (Demarquilly, 1969; Dijkstra and Becker, 1960; Schneeberger and Schoch, 1968) or dry matter (Gross, 1970; Gross and Averdunk, 1974; Zscheischler et al., 1974)
Genotype With respect to the available varieties at comparable stages
of maturity there is only a negligible effect of genotype. Exceptions are, for ruminants, new varieties high in lysine and new types becoming available with possibly higher digestibility of stalks and leaves and reduced lignification (e.g. brown midrib gene).
Fertilisation Fertilisation affects yield much more than nutritive value
(summarised by Zimmer, 1973). Increasing nitrogen application, for example, resulted in 12.3% and 12.6% variation respectively in SE or DM yield/ha, but only 1.5% for SE content (Primost, 1964) .
Epiphytic micro-organisms A specific epiphytic microflora is associated with maize
and is characterised by a high total number of micro-organisms, E. coli, and particularly, yeast (Koch et al., 1973).
THE ENSILAGE PROCESS AND NUTRITIVE VALUE
Fermentation In general the relationships between the ensilage process,
changes in nutritive value and extent of losses are known (Figure 1).
The production of fatty acids causes energy losses between 3.5% for lactic and 38% for acetic.
Some alcoholic fermentation seems characteristic with maize; this is DM-consuming but not energy-consuming; lower utilisation by animals seems possible (Laube, 1967) . Aerobic processes and/or secondary fermentation during storage depend mostly on technology and can be minimised. Heating during unloading depends on a
292
combination of the factors and microorganisms; significant losses are possible and precautions are necessary. Seepage losses in highly digestible material occur if the DM content is below 25%.
From these points the unavoidable reduction of energy content is calculated to be 30 50 g SE/kg DM: digestibility decreases by around 2 5 units (Table 2); DM losses are in the range 10 15%.
TABLE 2 DIGESTIBILITY OF ORGANIC MATTER IN FRESH AND ENSILED MAIZE
Author
Andrieu Nehring Harris
Schneeberger
Year
1970 1972 1965
1971
η
16 5 4
4
Fresh
72.2 74.2 + 1.48 73.9 + 0.85
75.5 + 0.99
Silage
71.5 71.2 + 2.78 73.0 + 1.63
71.8 + 1.47
MATURITYNUTRITIVE VALUEENSILING
SIE/ TS SE I DM
— frischer Mais / fresh corn Moissiloge / corn-s Hoge
Ι ,
L « IS IS 20 22 2i 26 26 30 32 34
1301 TSGeholl DM conteni
Figure 1
293 The previous statement on unavoidable losses or changes is based on the supposition that intensive homolactic fermentation took place supported by optimal technological conditions. Further factors have to be borne in mind.
Heterolactic or butyric type of fermentation results from suboptimal technology with extended respiration, high temperatures in certain climates and soiled or frozen material. These factors may reduce quality and cause higher losses as well as changes in energy content. Significant relationships between these parameters can be given (Hönig, 1972; Uchida and Sutoh, 1971; Zimmer, 1972), and an additional 20 - 40 g SE units/kg DM may be lost.
Technology There are close connections between organisation and/or
physical treatment and the biological process. Extended filling time by poor organisation or oversized silos extends respiration, wastes carbohydrates and increases the risk of heating during unloading. Specific data are not available.
Anaerobiosis is the basic requirement for good fermentation. The effect of aeration by leaky silos or unsuitable covering, on the other hand, becomes measurable via reduced quality and increased losses.
Positive effects of chopping to around 10 - 20 mm particle size are explainable by higher density and better disintegration of material (Hamm and Dijkstra, 1971; Zimmer, 1972). Modern techniques in principle now allow greater fineness even for mature material. Increasing fineness from 14mm to 4 mm by using a recutter does not produce a biological effect but rather a better utilisation of silo capacity (Table 3). However, this process results in an increase of over 200% in power requirement (Hönig).
NPN-additive Effect of NPN on nutritive value, its application and dose,
are well known. Adding NPN also stabilises fermentation; a significant increase in lactic acid was observed, with normal or lower amounts of VFA (Gross et al., 1969; Shirley, 1972; Owen, 1971). In Germany, urea and Maisfertil (mixture with minerals) are in common use while Pro-sii, a liquid containing
TABLE 3 EFFECT OF CHOPPING TREATMENT ON MAIZE
Treatment
14 mm 7 mm 4 mm
Recutter
Density
relative
100 106 114 125
Org. VFA % of total
36 36 36 34
acids Lactic % DM
6.0 5.5 5.9 6.5
Los co0 % DM
3.7 3.7 3.4 3.1
ses Energy % total
7.6 7.2 8.3 7.4
Instab 4 day
relative
91 109 121 79
ility11
8 day relative
105 109 107 79
Grain ^ in silage
% DM
19.0 15.0 12.5 5.5
in faeces % DM
intake
-5.8 -2.2
Energy requirement KWh/1
-1.6 2.1 3.5
relative
-100 136 223
1) Instability: mean of 4 or 8 day losses = 100 2) Grain: untouched in faeces as % of DM intake
(Honig, 1975)
295 ammonia is under experimentation (König, 1975).
Heating and its effects The exothermic process of heating during unloading has been
studied fairly well up to now (Hönig, 1972, 1975; Morwarid, 1969; Beck and Gross, 1964; M.K. Woolford, unpublished, 1975).
As a result of both aeration and the increase of yeasts and bacteria to a critical population during the filling period, significant losses and a lowering of the energy content occur during unloading. Depending on time, DM losses rise to 5 - 15% or more (Figure 2). The reduction of SE concentration in unstable maize amounts to 10 to over 30 g SE/kg DM and protein decomposition begins.
HEATING OF MAIZE-SILAGE - EFFECT OF AERATION -
( C our reges. Honig. 1975 )
% ί δ
ιο Ui !" 2>oI
5
AERA Tl ON
/ ANAEROBIC
/ /
' f | 1 1 1 1 1 1 1 — / 2 3 7 6 9 days
Figure 2
The inhibiting effect of organic acids such as propionic, acetic, even butyric, but not formic against fungal activity is well known. The application of acids to prevent heating has to be carried out during the filling of the silo and depends, for practical use, mostly on the price of the additive. New research
296
results, (Hönig, 1975) indicate the same effect by using either urea (Figure 3) or Prosil. The risk of heating was reduced significantly
Heating of maize-silage Effect of UREA (Honig 3751
% 20
10 5. Q
0
/
//
s> //
100
I 50
■ without UREA ln = 19)
■ with UREA <n=t7)
0 12 3 4 5 7 9 days
\ %
_
'012345 7 9 days storage time
Figure 3
'Stalklage' and frozen maize After harvesting the ear the remaining stalks and leaves
provide an additional valuable product. Using this as 'stalklage' is very common in the USA (Colenbrander et al., 1971 a,b) and should be recommended in Europe too. Nutritive value depends on the maturity of the whole plant. Stalklage harvested after picking cobs in dough stage has an energy concentration of about 400 450 g SE/kg DM. Maize straw remaining after threshing has a digestibility below 55% and an SE concentration between 210 and 380 g/kg DM (Koch, 1971). For conservation one has to add water to achieve sufficient fermentation, and NPN is added.
The effect of early freezing has not been so thoroughly studied. Crude nutrient content will not change very much (Caldwell, 1971), but significant losses will occur. Gordon
297
(1968) observed DM losses of 19 27% of total yieldDigestibility decreases too and energy content was lowered by about 44 g SE/kg DM. Humid climatic conditions after freezing will be dangerous, because the epiphytic flora is shifting to proteolytic and coliforms and causes poor fermentation (Nehring, 1958; Wetterau, 1972). Dry climatic conditions have been found to cause a decrease of overall digestibility and reduction in energy of 20% (Melotti, 1969).
REFERENCES
Andrieu, M., 1970. Valeur alimentaire du Maïsfourrage. Le maïs, plante fourragère ITCF.
Beck, Th. and Gross, F., 1964. Ursachen der unterschiedlichen Haltbarkeit von Gärfutter. Das wirtschaftseigene Futter 10, No.4, 298 312.
Caldwell, D.M. and Perry, T.W., 1971. Relationships between stage of maturity of the corn plant at time of harvest for corn sllaqe and chemical composition. J. Dairy Sci. 54, 533 536.
Colenbrander, V.F., Muller, L.D., Watson, J.A. and Cunningham, M.D., 1971. Effects of added urea and ammonium polyphosphate to corn stover silages on animal performance. J. Anim. Sci. 33, 1091 1096.
Colenbrander, V.F., Muller, L.D., and Cunningham, M.D., 1971. Effects of added urea and ammonium polyphosphate on fermentation of corn stover silages. J. Anim. Sci. 33, 1097 1101.
Cummins, D.G., 1970, Quality and yield of corn plants and component parts when harvested for silage at different maturity stages. Agron. J. 62 781 784.
Davis, W.E.P. and Bowden, D.M., 1969. Effect of growth stage at harvest on the nutritive value of a grain corn grown for silage. Can. J. Plant Sci. 49, 361 370.
Demarquilly, C , 1969. Valeur alimentaire du maïs fourrages. I. Composition chimique et digestibilité du maïs sur pied. Ann. Zootech, le, 17 32.
Dijkstra, Ν.D., 1960, Digestibility and feeding value of green and ensiled maize fodder. Versi, v. LBK. Onderzoekingen 66, 14.
Giardini, Α., 1964. Ricerche sperimentali sulla foraggicoltura per insilamento in torre. Estratto da progresso Agrie. 9/10, No. 7,9,11, and 12.
Gordon, C.H., Derbyshire, J.C. and van Soest, P.J., 1968. Normal and late harvesting of corn for silage. J. Dairy Sci. 51, 1258 1263.
Gross, F., Koch, G. and Koller, G., 1969. Harnstoff im Maisgärfutter.
298
Das wirtschaftseigene Futter 15, 210 227. Gross, F., 1970. Einfluss des Erntezeitpunktes auf den Futterwert von
Maisgärfutter. Das wirtschaftseigene Futter 16, 306 336. Gross, F. and Averdunk, G., 1974. Der Gehalt an Nährstoffen in Maissilagen,
ihre Verdaulichkeit und ihre Beziehungen zum Nährstoffgehalt. Das wirtschaftseigene Futter 20, 66 74.
Hamm, G.G. and Dijkstra, N.D., 1971. Effect of two different harvesting methods on the resulting fodder maize. Bedrijfsontwikkeling, Editie Veehoudenj 2, 53 55.
Harris, C.E., 1965. The digestibility of fodder maize and maize silage. Expl. Agrie. 1, 121 123.
Honig, H., 1972. Änderungen des Nährwertes von Gärfutter bei unterschiedlicher Siliertechnik. Vortrag auf der 16. Jahrestagung der Gesellschaft f. Landbauwissenschaften in Bonn, Sept.
Honig, H., 1975. Umsetzungen und Verluste bei der Nachgärung. Das wirtschaftseigene Futter 21, 25 32.
Koch, G., 1971. In Rintelen, P. Mais. Ein Handbuch über Produktionstechnik und Ökonomik, 219 246.
Koch, G., Morwarid, A. and Kirchgessner, M., 1973. Zum Einfluss der Mikroorganismen der Maispflanzen auf die Stabilität der Silagen. Das wirtschaftseigene Futter 19, 15 20.
Laube, W., 1967. Zur Problematik der Silierung zuckerreicher Futterstoffe unter besonderer Berücksichtigung der Alkoholbildung. Tagungsberichte Nr. 92 der DAL, Berlin, 169 176.
Melotti, L., 1969. Determination of the nutritive value of maize silage and sun dried maize fodder in a trial on digestibility. Boletim de Industria Animal 26, 335 344.
Morwarid, Α., 1969. Silierversuche zur Stabilität von Maissilagen. Dissertation Weihenstephan.
Nehring, K. , 1958. Über Probleme der Einsäuerung von Maisgärfutter und Grünmais. Deutsche Landwirtschaft 9, 483 488.
Nehring, K., 1972. Futtermitteltabellenwerk. VEB Dt. Landw. Verlag, Berlin. Owen, F.G., 1971. Silage additives and their influence on silage fermentation.
Proc. Int. Silage Res. Conf. Washington DC, 79 112. Primost, E., 1964. Ertrag und Qualität von Silomais in Abhängigkeit von
NDÜngung und Witterung. Das wirtschaftseigene Futter 10, 10 21. Rosenstiel, F., 1966. In Liesegang, F. KTBL Kalkulationsunterlagen für
Betriebswirtschaft 3, M.10. Schneeberger, H. and Schoch, W., 1968. Untersuchungen über den Futterwert
von Mia
299
von Maissilagen. Schweiz. Landw. Forschung VII, H.3/4, 337 - 361. Schneeberger, H., 1971. Das wirtschaftseigene Futteraktuelle Probleme der
Verwertung. Schweiz. Landw. Monatshefte 49, 213 - 225. Shirley, J.E., 1972. Influence of varying amounts of urea on the fermentation
pattern and nutritive value of corn silage. J. Dairy Sci. 55, 805 - 810. Thomson, A.J. and Rogers, H.H., 1968. Yield and quality components in maize
grown for silage. J. Agrie. Sci. Camb., 71, 393 - 403. Uchida, S. and Sutoh, H., 1971. Untersuchungen über die chemische Zusammen
setzung und Qualität von Silage. IX. Beziehung zwischen Qualität und Futterwert. Sei. Rep. Fac. Agr. Okayama Univ. 38, 51 - 58.
Wetterau, H., 1972. Silageherstellung. VEB Dt. Landw. Verlag Berlin. Zimmer, E., 1972. Ernte und Konservierung von Silomais. Hann. Land- u.
Forstw. Zeitung 125, Nr. 42. 8-10. Zimmer, E., 1973. Nährwert von Mais in frischem, siliertem und getrocknetem
Zustand. Europaische Vereinigung für Tierzucht, Wien (Manuskript) Zscheischler, J., Gross, F. and Hepting, L., 1974. Einfluss von Schnittzeit,
Sorte, und Standweite auf Ertrag und Futterwert von Silomais. Bayerisches Landw. Jahrbuch 51, 611 - 636.
Animal Feed Science and Technology. 1(1976) 301311 301
Itlsevier Scientific Publishing Company, Amsterdam Printed in The Netherlands
INFLUENCE OF ENSILING MAIZE EARS AND GRAIN ON CHEMICAL COMPOSITION, CONSERVATION LOSSES AND DIGESTIBILITY
R. PARIGIBINI and G.M. CHIERICATO Istituto di Zootecnica Universita di Padova, Italy
ABSTRACT
No marked variation in proximate composition was observed during the ensiling of maize ears and grain. Silages had a significantly lower level of insoluble Ν and a higher level of NH and urea Ν than fresh products. The production of organic acid declined very rapidly in maize silages as dry matter content increased.
Percentage losses in ensiling were very small, except for insoluble N. Data suggest that reduced fermentation and conservation losses take place when dry matter content of maize ears and grain increases above 65 and 70% respectively.
Apparent digestibility of nutrients and energy of maize ears and maize grain silage appeared to be strongly affected by the dry matter content at ensiling time, the coefficients being higher when dry matter was lower.
INTRODUCTION
The harvesting and storage of high moisture cereals has become both practical and widespread during the past ten years.
According to the present conditions in Italy and in other European countries, this trend might be expected to continue to increase in the future.
Ensiling is the technique more commonly used, but recently the storing of high moisture grain has been increased by the use of chemical preservatives, such as organic acids.
The objectives of this paper are to summarise and briefly discuss some recent results of research on the ensiling of ground, highmoisture maize ears and grain with reference to the effect on chemical composition, conservation losses and nutritive value.
302
INFLUENCE ON CHEMICAL COMPOSITION
Before discussing the effect of ensiling on chemical composition of maize ears and grain, it is opportune to point out that chemical composition is strongly affected by the stage of maturity of the maize. Thornton et al. (1969a,h), found that the increase in dry matter content of ears and grain from early milk to mature stage, was associated with changes in chemical composition and nutritive value.
With advancing maturity, ether extract and NFE percentage increased and crude fibre and ash decreased.
Little information is available on the chemical modification of ears and grain during ensiling.
Results of two experiments performed in our Institute on ground maize ears ensiled at two different moisture levels, using the "buried bags" technique, are given in Table 1.
In general, no marked variation in proximate composition was observed during ensiling.
The DM content seemed not to be much affected, but in our first trial there was a small but significant decrease in DM percentage.
The most important and significant variation concerned the Ν fractions and organic acid production. Ensiled maize ears had significantly (P^O.Ol) lower levels of insoluble Ν than the fresh product (88.7 vs 95.2% of the total N) and higher levels (P^O.05) of ammonia and urea Ν (0.5 vs 1.1% of total N).
303
TABLE 1 EFFECT OF ENSILING ON COMPOSITION OF MAIZE EARS - (% OF DM)
References:
No. of samples DM Ci) Crude protein (Nx6 Ether extract Crude fibre Ash NFE Insoluble Ν <2)
NH3-N+urea-N (2)
PH Acetic acid Lactic acid
Bo
25)
isembiante Fresh
o 77.2 9.6 4.1 5.2 1.5
79.6 95.2 0.5 6.0 -
-
et al., 1974b .Silage
9 76.6* 9.6 3.8 4.0 1.5
81.1 88.7** 1.1* 5.2** 0.13 0.14
Rioni,M and Fresh
6 68.0 8.9 4.1 8.5 1.5 77.0 -
-
-
-
-
Lanari, D (1) Silage
6 68.2 8.9 4.0 6.3 1.5
79.5 -
-
4.3 0.24 0.47
(D- Personal communication 1976 (2) - % of total Ν * - P<0.05 ** - Ρ <0.01
The pH value declined from 6.0 in the fresh maize ears to 5.2 in the high DU silage and to 4.3 in the lot· DM silage.
The data reported in Table 2, obtained in two different experiments performed in our Institute, indicate a similar trend in ensiled ground maize grain.
The sole significant variation cpncerns N^-N+urea-N (0.6 vs 1.0% of total N, in the fresh and ensiled grain respectively), pH value (6.2 vs 4.9) and acetic and lactic acid production.
The above mentioned data, regarding both maize ears and grain, suggest that little fermentation took place, because moisture was inadequate to support a more active fermentation.
In fact, other authors found more variation and fermentation when ensiling maize ears and maize grain of higher moisture content.
Baldoni et al. (1970) found from 1.8 to 3.1% of NH3-N in the total N; 0.4 - 0.5% of acetic acid in the DM and 0.9 to 2.7% of lactic acid in the DM in maize ear silage containing from 65.3 to 69.6% Df'.
pH
Acetic ac
%DM
Lactic ac
%DM
5.5
5.0
4.5
4.0
3.5
0.6
■0.4
0.2
0
2.0
• 1.5
1.0
0.5
0
Ear silage Grain silage
55 60 65 70 75 '//. D-
65 DM
70 75 % DM
80
Figure 1 Effect of DM Content on Organic Acids and pH of Maize Silage REFERENCES · Rioni and Chiericato, 1972; Δ Thornton et al. 1969a; OBonserabiante and Parigi-Bini, 1972
ABaldoni et al., 1970; D Bonsembiante et ai., 19/4a; ■ Bonsembiante et ai., 1974b X Lanari and Rioni, 1976; O Klosterman et ai., 1960.
305
D a n l e y and V e t t e r ( 1 9 7 4 ) s h o w e d more e x t e n s i v e f e r m e n t a t i o n
when m a i z e g r a i n w a s e n s i l e d a t h i g h e r m o i s t u r e l e v e l s .
The d a t a r e p o r t e d i n T a b l e 1 and 2 and r e s u l t s p u b l i s h e d b y
o t h e r a u t h o r s , c l e a r l y d e m o n s t r a t e t h a t DM c o n t e n t a t e n s i l i n g
t i m e i s o f m a j o r i m p o r t a n c e i n r e g u l a t i n g t h e f e r m e n t a t i o n p a t
t e r n o f m a i z e e a r s and g r a i n .
TABLE 2
EFFECT OF ENSILING ON COMPOSITION OF MAIZE GRAIN (% OF DM)
References :
No. of samples DM (%) Crude protein (Nx6 Ether extract Crude fibre Ash NFE Insoluble Ν (2)
NH3N+ureaN (2)
pH Acetic acid Lactic acid
Bon
.25)
sembiante Fresh
9 77.8 9.7 4.6 2.5 1.4 81.8 93.3 0.6 6.2
et al., 1974b Silage
9 77.6 9.5 4.3 2.2 1.5
82.5 92.0 1.0* 4.9** 0.13 0.13
Rioni,M and Fresh
6 71.9 9.6 4.9 4.2 1.7
79.6
Lanari,D (1) Silage 6 71.5 9.6 4.8 3.5 1.7
80.4
4.1 0.17 0.69
(1) Personal communication 1976 (2) % of t o t a l Ν
* Ρ < 0 . 0 5 ** P < 0 . 0 1
In Fig. 1, data concerning pH and organic acids are plotted against DM content of maize ears and grain.
As the DM percentage increases, the lactic and acetic acids decrease and pH value increases. In the maize ear silage, lactic acid decreases from about 1.5% to r>.2% of DM; acetic acid falls from about 0.5% to 0.1% of DM; and pH value rises from 3.8 to 5.2, as the DM increases from 5P% to 75%
The production of organic acids (namely, fermentation) declines very rapidly when the Dì* content of maize ears increases above 65%. Particularly, the lactic acid content in the DM falls below 1% and pH value rises towards 5.0.
A similar trend can be observed in maize grain silage, when
306
DM percentage goes over 70%. The cell wall composition of both silages is presented in
TABLE 3 CHEMICAL COMPOSITION OF MAIZE SILAGES (Van Soest method)
DM CWC ADF Hemicellulose Cellulose Lignin
t.
» « 'a
* '*
DM DM DM DM DM
Ma ize ear
71.2 14.9 5.4 9.5 4.4 0.9
si lage Maize grain silage
73.5 10.2 2.6 7.6 2.1 0.5
Reference: Bonsembiante et al.. 1974a
As expected, the maize ears contained more CWC, ADF, cellulose and lignin. Other analyses performed on maize ear silage by Rioni and Chiericato (1972) showed higher CWC and ADF (21.1 and 8.90 of DM respectively) because the ear, harvested by a different method, contained more cobs.
Data on mineral composition are reported in Table 4. In both silages, the Ca, Ρ, Mg, Κ, Μn, and Cu levels were not different from those reported by NAS NRC (1969) . The Na content was lower and Zn higher. The Fe level in maize ear silage was lower than the NRC value, but similar to the one found by Piva et al. (1974). TABLE 4 MINERAL COMPOSITION OF MAIZE EARS AND GRAIN SILAGES (% or ppm of DM)
No. Ca Ρ Na Mq Κ
of samples * 'i
% ■:,
t
Ma ize ear sil
3 0.042 0.290 0.006 0.113 0.410
age Maize g rain silage
3 0.018 0.320 0.006 0. 113 0.320
307
TABLE 4 (Cont)
Mn Zn Fe Cu
ppm ppm ppm ppm
Maize ear
5.4 20.3 47.3 3.5
silage Maize grain silage
4.3 25.0 29.5 ' 2.5
Reference: Bonsembiante et al., 1974b
ENSILING LOSSES
The results of two experiments, where the percentage losses during the ensiling of maize ears and maize grain containing about 77% of DM were measured by the "buried bags" technique in plastic silos, are shown in Fig. 2.
In both silages, the DM and 0M losses were very small and similar to those observed by Baldoni et al. (1970) in maize ears (67% DM) ensiled in a tower silo. According to the same authors, the DM losses were higher (2.7 3.2%) in a trench silo and a plastic bag silo.
The insoluble Ν showed losses (8.6% in ensiled maize ears and 3.8% in ensiled maize grain), with corresponding gains in NH3N+ureaN (Fig. 2).
The above percent losses and those reported by Chandler et al. (1975) appear to be modest and were measured on silages of relatively high DM content.
In such conditions, extensive fermentation does not take place and it agrees with data presented in Fig. 1, showing that fermentation increases when DM percentage of maize ears goes below 65%
APPARENT DIGESTIBILITY
Data on apparent digestibility of nutrients and energy of ensiled maize ears and grain, are shown in Table 5.
Digestibility trials were performed on young bulls receiving 1.3 1.5% of their body weight of a diet containing 90% of maize ears or grain and 10% of a protein, mineral and vitamin supplement.
Dry matter
Organic matter
Total Ν
Insoluble Ν
Ether extract
Total carbohydrates
NH3-N + u r e a - Ν
40 80 120
ear silage
grain silage
10 losses
160 200 % g a i n
Figure 2 Percent Losses in Maize Silage REFERENCE Bonsembiante et al., 1974b
309 Digestibility of both silages was calculated indirectly.
The apparent digestibility of nutrients and energy appears to be strongly influenced by the DM content of ear silage, the coefficient being higher when the DM was lower (Ρ<Ό.01).
TABLE 5
APPARENT DIGESTIBILITY OF ENSILED MAIZE EARS AND GRAIN OF DIFFERENT DM CONTENT
DM (%) No. of animals Apparent digestibility (%) DM OM Crude protein
(Nx6.25) Ether extract Total carbohydrate Energy CWC ADF Hemicellulose Cellulose
Maize ear silage *
63.2 4
83.3 84.5
61.9 84.4 86.8 81.7
** 71.1 8
74.5 75.5
51.1 67.8 78.7 71.4 55.4 46.7 60.8 48.3
Maize grain silage * •
73.5 8
83.0 83.9
57.8 72.8 87.7 80.5 71.5 62.2 76.5 63.4
REFERENCES: * Bonsembiante and Par ig i Bini , 1972 ** Bonsembiante et a l . , 1974a
Recen t r e s u l t s of L a n a r i and R i o n i (1976) c o n f i r m t h i s t r e n d .
The d i f f e r e n c e can p r o b a b l y be e x p l a i n e d by t h e more f a v o u r
a b l e c h e m i c a l c o m p o s i t i o n of immature e a r s a t e n s i l i n g , t i m e . In f a c t , w i t h a d v a n c i n g m a t u r i t y , t h e CWC of cobs i n c r e a s e s and t h e d i g e s t i b i l i t y d e c r e a s e s (Thorn ton e t a l . , 1 9 6 9 b ) .
F u r t h e r m o r e , s e v e r a l a u t h o r s showed h i g h e r d i g e s t i b i l i t y of h i g h m o i s t u r e , t h a n m a t u r e , maize k e r n e l s (McLaren and Matsush ima , 1968; Tonroy e t a l . , 1 9 7 4 ) .
F u r t h e r m o r e , h i g h m o i s t u r e e a r s a r e f e rmen ted t o a g r e a t e r e x t e n t t h a n low m o i s t u r e e a r s , and t h a t can c o n t r i b u t e t o improve
310
digestibility. From the above discussion it can he concluded that reduced
fermentation and conservation losses take place in maize ears and grain ensiled at relatively high DM content (i.e. more than 65?, or 70% DM). At the same time, digestibility appears to be lower than in silages with higher moisture content.
Therefore, the choice of DM content at ensiling time, when not imposed by climatic conditions, will depend upon utilisation in animal feeding (level of nutrition, roughage to concentrate ratio, etc.).
However, ensiling seems to be the more suitable conservation technique for high moisture maize, in relation to present high drying costs.
REFERENCES
Baldoni, R., Giardini, A. and Vecchiettini, M., 1970. Ricoveri, Silomais e "pastoni" nell'allevamento del vitellone - Informatore Agrario, 28, 2247.
Bonsembiante, M. and Parigi-Bini, R., 1972. Ricerche sulla digeribilità e sul valore nutritivo del mais. Effetto del trattamento idrotermico della granella e della conservazione in silo della spiga umida. Alimentazione Animale, 1/33.
Bonsembiante, M., Rioni, M., Parigi-Bini, and Chiericato, G.M., 1974a. Ricerche sui pastoni di mais nella produzione del vitellone. Revista di Zootecnia e Veterinaria, 2, 97.
Bonsembiante, M., Parigi-Bini, R., Cesselli, P. and Chiericato, G.M., 1974b. Modificazioni chimico-nutritive e perdite di insilamento del foraggio di mais ceroso e dei "pastoni" di pannocchia e di granella. Revista di Zootecnia e Veterinaria, 6, 477.
Chandler, P.T., Miller, C.N. and Jahn, E., 1975. Feeding value and nutrient preservation of high moisture corn ensiled in conventional silos for lactating dairy cows. Journal of Dairy Science, 58, 682.
Danley, M.M. and Vetter, R.L., 1974. Artificially altered corn grain harvested at three moisture levels. I. Dry matter and nitrogen losses and changes in the carbohydrate fractions Journal of Animal Science, 38, 417.
Klosterman, E.W., Johnson, R.R., Scott, H.W., Moxon, A.L. and Van Stavern, J., 1960. Whole plant and ground ear corn silages, their acid content, feeding value and digestibility. Journal of Animal Science, 19, 522.
311
Ulnari, D. and Rioni, M. 1976. Rate of growth, feed utilisation and digestibility observed with diets containing ensiled maize grain or maize ears fed alone or in mixtures. In J.C. Tayler and J.M. Wilkinson (Editors) The Maize Crop as a 3asic Feed for Beef Production. Animal Feed, Science and Technology
NAS and NRC, 1969. United States Canadian tables of feed composition. Pubi. 1694, NAS, Washington, DC.
McLaren, R.J. and Matsushima, J.K., 1968. Digestion of ensiled reconstituted corn. Journal of Animal Science, 27, 1171.
Piva, G., Maroadi, Α., Santi, E. and Amerio, M., 1974. Sulle variazoni del pastone di mais, diversamente corretto, nel corso dell'insilamento. Alimentazione Animale, 1/37.
Rioni, M. and Chiericato, G.M., 1972. Impiego del "pastone di pannocchia", della pannocchia secca di mais e del fieno di erba medica e di loietto nella produzione del vitellone. Alimentazione Animale, 11/25.
Thornton, J.H., Goodrich, R.D. and Meiske, J.C., 1969. Corn maturity. I Composition of corn grain of various maturities and test weights. Journal of Animal Science, 29, 977.
Thornton, J.H., Goodrich, R.D. and Meiske, J.C, 1969b. Corn maturity. Ill Composition, digestibility of nutrients and energy value of corn cobs and ear corn of four maturities. Journal of Animal Science, 29, 987.
Tonroy, B.R., Perry, T.W. and Beeson, W.M., 1974. Dry,ensiled highmoisture, ensiled reconstituted highmoisture and volatile fatty acid treated highmoisture corn for growingfinishing beef cattle. Journal of Animal Science, 39, 931.
Animal Feed Science and Technology. 1 (1976) 313-326 3 1 3
Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
EFFECT OF MAIZE SILAGE HARVEST STAGE ON YIELD, PLANT COMPOSITION AND FERMENTATION LOSSES
A. GIARDINI, F. GASPARI, M. VECCHIETTINI and P. SCHENONI C.N.R. Centro di Studio per la Conservazione dei Foraggi, Agronomy Department, university of Bologna, Italy.
ABSTRACT
A two year trial was conducted in the southern Po river valley (near Bologna) , in order to define the optimum harvest stage for maize silage under various cropping conditions (water availability, hybrid earliness).
Maximum green fodder yield was reached, for all treatments, at the milk stage, 20-22 days after flowering, with a whole plant DM content of about 20-21%. ,. On the other hand, maximum DM yield was reached at 40-45 days after flowering at a whole plant DM content of 42% and 38% for maize grown on irrigated and unirrigated land, respectively.
Differences between hybrids were only apparent in unirrigated conditions where between the early and late hybrids again a range from 42% to 38% in whole plant DM content was observed, but with a delay of about a week for the former.
Forage chemical composition, determined for the irrigated crop only, generally improved with the'delay in harvest, mainly because of a reduction in crude fibre and an increase in N-free extract.
In order to study the effects of harvest stage, i.e. of forage DM content, on the storage process, the experiments conducted during the last ten years at the "Centro Conservazione Foraggi" were elaborated. With the delay in harvesting the DM storage losses and the maize silage acid content decreased linearly, whereas the pK value increased. For high moisture grain and ear, except for the non-significance of DM losses, the same trend was recorded.
The results of this research, finally, indicate the advantage of harvesting at the maximum crop yield stage, therefore after dough ripeness.
314 INTRODUCTION
Among the several aspects concerning the use of maize silage in beef cattle production, the choice of the right forage harvest stage represents, without a doubt, one of the most incisive factors for technical and economic results. In practice this involves the identification of the maturity stage which represents the best compromise between quantity and quality of production.
After flowering and up until dough stage ripeness, the maize plant has a really surprising productive potential (up to and more than 300 kg/ha/day) and an equally surprising dynamism on the forage quality because of the rapid modification in the ratio among the plant components. This means that to harvest too early or too late, even by just a few days, always causes considerable losses; in the first case a lower DM yield, in the second a quality deterioration.
The terms of the problem, however, are not very simple since numerous investigations showed noticeable differences in productive (Caldwell and Perry, 1971; Cántele and Giardini, 1966; Cummins, 1970; Geasler et al., 1967; Giardini, 1969; Giardini and Toderi, 1964; Johnson et al., 1966; Nelson et al., 1969; Perry et al., 1968; Pollacsek and Caenen, 1970), qualitative (Andrieu, 1970; Cummins, 1970; Giardini and Toderi, 1964; Johnson et al., 1966; Owens et al., 1967) and Storage processes (Andrieu, 1970; Gordon et al., 1968; Nelson et al., 1969), depending on the maize silage harvest stage. The variability in these results permits us to forecast that the optimum harvesting stage is closely connected to pedo-climatic factors and to the cultural practices adopted, and suggest that this problem has to be pursued in single environments.
Our field trials were conducted for two years on a fertile loam-clay soil on the southern Po river plain (near Bologna). According to Emberger (1933), these areas are classified as a temperate Mediterranean climatic zone with almost 50% of semi-arid type years, since the total summer rainfall (June, July, August) does not exceed 110 mm (Mancini, 1941). In this period the mean daily evaporation from a "Class A" pan is normally 5.7 mm/day. The unirrigated maize crop presents higher risks
315 because of drought damage and it is usually watered 23 times, depending on the rainfall trend.
We studied the effect of the harvest stage in relation to irrigation and hybrid earliness (2 hybrids: Dekalb 61, FAO class 300; Funk's G77, FAO class 600), the former in order to evaluate the different water availability effects, the latter to verify the influence of the temperature which is higher during the early hybrid's ripeness.
Recordings began at flowering and continued at weekly intervals until grain maturity.
EFFECT OF STAGE OF MATURITY ON YIELD
The comparison between irrigated and unirrigated land on the average data for hybrids is illustrated in Figure 1. The interaction of hybrid earliness χ harvest stage was also significant owing to the hybrids' different trend on unirrigated land (Figure 2).
The highest green fodder yield was reached at the milk stage, about 20 days after flowering and with 2223% whole plant DM content. After this the forage yield decreased almost linearly up to combinematurity.
In optimum soil moisture conditions the green fodder yields at flowering and at the dough stage were approximately the same, around 80% of the maximum yield. Instead, in the unirrigated environment the green fodder yield at flowering was lower and the rate of decrease following the milk stage was less accentuated. This trend was particularly evident in the early hybrid whose yield at flowering barely reached 70% of the maximum, whereas at the dough stage it still retained a yield level around 95%.
The reduction in green weight following milk ripeness was due almost exclusively to a weight loss by the plant's vegetative components, whereas the ear (grain + cob) maintained its weight almost unaltered (about 25% of the maximum green fodder yield) for the whole period until combinematurity.
Maximum DM yield was found 810 days after the dough stage with a DM content of around 40% in the whole plant and 6062% in the grain. In unirrigated conditions, particularly with the
316
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318 early hybrids, the maximum yield stage was delayed by about a week.
In the following stages a certain decrease in the DM production was noted to be due to loss of leaves and ears, breaking of tassel and corn borer damage.
The increase in DM yield after flowering was due to the growth of the ear and especially of the grain, whereas the plant's vegetative components remained at the yield level reached at flowering with a slight increase up to the milk stage and a certain decrease after dough ripeness.
The maize plant's growth rate after flowering is really surprising. During the first 40-4 5 days, i.e. up to the dough stage, the plant produces, in fact, about 60% of the total DM yield; a productive potential, therefore, which is double that recorded in the period preceding flowering.
The ear yield increases almost linearly up to the dough maturity; at this stage the grain DM yield is about 90% of the maximum yield which will be reached at physiological maturity, with lower values on irrigated land and for the early hybrids.
It is very interesting to consider some of the indicative parameters which can be used for production forecast purposes. Among these and with reference to the irrigated environment, the following should be remembered:
Maximum DM yield = Divisor green fodder yield at flowering or at dough stage : 2.6 green fodder yield at milk stage Maximum ear DM yield = green fodder yield at flowering or at dough stage green fodder yield at milk stage maximum DM yield Grain DM yield = green fodder yield at flowering or at dough stage green fodder yield at milk stage maximum DM yield Shelled grain yield (15.5% moisture) = green fodder yield at flowering or at dough stage green fodder yield at milk stage maximum DM yield
3.4
6.0 6.5 1.9
7.2 7.8 2.3
6.2 6.7 2.0
TABLE 1 DRY MATTER CONTENT AND PLANT COMPOSITION FOR FIVE CHARACTERISTIC MATURITY STAGES
Treatments
Irrigated land
Non-irrigated land
Early hybrid (non-irrigated land)
Medium late hybrid (non-irrigated land)
Stages of maturity
flowering milk stage dough stage physiological maturity combine-maturitj
flowering milk stage dough stage physiological maturity combine-maturitj
flowering milk stage dough stage physiological maturity combine-maturity
flowering milk stage dough stage physiological maturity combine-maturiti
Whole plant 15.5 20.9 34.1 47.6 51.8
16.4 22.0 33.0 43.3 48.0
16.8 22.4 33.7 44.0 48.3
16.3 21:2 33.4 43.8 48.7
% Stalk
14.3 18.0 21.7 26.6 29.6
14.8 18.5 21.3 23.5 24.2
13.7 19.0 22.0 24.4 25.0
16.0 17.9 21.0 22.2 25.8
of dry matter Leaf
22.2 24.0 32.3 57.2 61.8
22.9 27.0 32.3 44.9 52.2
23.1 26.0 31.8 41.4 51.2
21.8 28.0 32.3 48.0 54.0
Husk
13.8 19.3 30.1 47.1 51.7
12.5 19.3 28.0 46.6 51.6
13.0 17.2 25.8 45.4 50.0
11.9 20.3 30.1 49.2 54.3
Cob Grain
23.2 43.0 54.5 47.3 66.9 50.3 71.5
24.6 38.8 53.7 47.5 67.4 54.1 71.3
26.0 37.7 52.5 47.7 63.6 49.6 68.9
22.3 40.0 53.4 47.0 71.3 58.0 74.1
% Sk.
60 43 38 36 36
56 41 36 35 36
55 39 36 33 33
57 42 37 37 37
in green fodder Lf.
21 18 17 13 11
25 18 20 19 17
26 18 19 17 17
25 18 21 18 17
Hk.
19 13 8 6 6
19 15 10 6 7
19 17 11 6 6
18 14 9 6 8
Cob Gn.
26 9 28 10 35 11 36
26 11 23 11 29 10 30
26 11 23 10 34 11 33
26 11 22 13 26 10 28
Sk.
55 38 24 20 21
51 35 23 19 18
47 35 24 18 17
56 35 23 19 19
% in Lf.
30 20 16 16 13
35 22 19 19 18
38 21 18 17 18
33 24 20 21 20
dry Hk.
15 13 7 6 6
14 14 8 7 7
15 14 8 7 6
11 13 8 7 7
matter Cot
11 10 11
12 12 11
12 11 11
13 12 12
Gn.
29 42 48 49
29 38 43 46
30 38 47 48
28 36 41 42
320 EFFECT OF STAGE OF MATURITY ON FORAGE QUALITY
As the plant ripening process continues, and with the increase in DM content, the ratio between plant components is progressively modified toward the grain fraction. This trend (Figure 3 and Table 1) is more accentuated in the stages immediately after flowering and decreases progressively after the dough stage. Thus, whereas the grain at milk ripeness only represents 15-16% of the forage dry weight (estimated value), at the dough stage this value increases to 40-42% until it reaches almost 50% at physiological maturity. On unirrigated land and above all for the late hybrid, which is notoriously more sensitive to drought, the forage grain content proves to be lower (5-8% less).
This trend also occurs with regard to the green weight proving that, at least under our trial conditions, water availability and hybrid earliness effects showed little influence on the changes in the DM content of plant components. The DM% variation in the whole plant is, therefore, mainly due to variations in the ratio between plant components rather than to the different DM% of each part. It also follows that the whole plant DM% shows a certain variability and, at a given growth stage, it proves to be greater the higher the grain content of the forage.
Therefore this parameter is not sufficiently predictive for the evaluation of the plant's different stages and in particular for the identification of the crop's maximum yield stage.
In our trials DM% value varied by 42% in the irrigated crop and by 38% in the unirrigated crop and the same difference was shown in this latter environment between the early and late hybrid.
Even other parameters advised by some authors, such as the grain DM%, the grain content in the green fodder and on the ear, proved to be of little diagnostic value since they varied with the environment and with plant earliness.
As plant ripening proceeds, the chemical composition of the forage also changes, mainly according to the modifications in the ratio between the different plant components, rather than
321
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to the analytical variations of the same in the different vegetative stages (Table 2 and Figure 3). In fact, the only significant differences were in the reduction of the Nfree extract and reducing sugars in the stalk, of sugars and fibre in the ear and of the crude protein in the leaves, and the increase in Nfree extract of leaves and ear.
CHEMICAL COMPOSITION FOR FIVE CHARACTERISTIC STAGES OF MATURITY (IRRIGATED LAND)
Plant components
Stalk
Leaf
Ear (husk + cob + grain)
Whole plant
Stages of maturity
flowering milk stage dough stage physiological maturity combine-maturity
flowering milk stage dough stage physiological maturity combine-maturity
flowering milk stage dough stage physiological maturity combine-maturity
flowering milk stage dough stage physiological maturity combine-maturity
Crude protein
7.0 4.0 4.0 3.9 4.0
18.2 16.4 12.5 8.5 8.2
11.8 10.0 9.0 8.8 9.0
11.1 9.0 8.4 7.8 7.8
Chemical composition (% dry Ether
extract
2.3 1.6 1.3 1.2 0.8
2.3 2.5 1.9 1.2 1.4
3.0 2.7 3.2 3.5 3.5
2.4 9.2 2.5 2.7 2.7
Crude fibre
30.8 30.2 31.3 32.7 36.0
25.5 25.5 27.3 29.2 29.0
19.0 20.0 12.0 11.3 9.8
27.4 25.0 19.1 . 18.4 17.8
Ash
5.2 4.7 5.0 5.2 6.0
11.0 12.0 12.0 12.8 13.1
4.0 3.0 1.5 1.2 1.2
6.8 5.4 4.0 3.9 3.8
matter) N-free extract
54.7 59.5 58.4 57.0 53.2
43.0 43.6 46.3 48.3 48.3
62.2 64.3 74.3 75.2 76.5
52.3 58.4 66.0 67.2 67.9
Reducing sugars
16.3 15.0 13.8 4.0 2.8
4.0 5.0 3.2 2.8 2.0
25.0 11.0 4.7 2.5 2.0
13.9 11.3 6.6 2.8 2.2
323 In the whole plant and therefore in the fodder, the greatest
modifications concern the increase in N-free extract and the reduction in sugars and fibre. The maximum rate of reduction in sugars occurred around the dough stage or just after, when root absorption ceased in the almost physiologically ripe plant, and the food reserves were transferred to the grain. Even protein and ash showed a certain decrease but this was much smaller, whereas the ether-extract remained almost constant.
EFFECTS ON FORAGE CONSERVATION
In order to answer this question the experiments carried out during the last ten years at the "Centro Conservazione Foraggi" were elaborated. In total, there were 24 trials with about 500 samples for maize silage and 22 experiments with about 200 samples for high-moisture grain and ear.
The results given in Figure 4 show a close correlation between fodder DM content and the storage process in the silo.
With a delay in harvesting and therefore with the increase in fodder DM, the DM storage losses and the maize silage acid content diminished linearly.
In particular, in our experiments, these decreases were 0.35, 0.25 and 0.10 points, respectively, for DM losses and for lactic and acetic acid contents for each 1% increase in DM at ensiling. The pH increased by 0.0136, whereas no significant variation was obtained for NH3.
With high-moisture grain and ear the decreases in lactic and acetic acids were 0.13 and 0.05, whereas for DM ahd ammonia nitrogen losses no significant correlation was recorded between losses and the content of moisture in the ensiled material.
The intensity of the fermentation process for maize silage depends mainly on the sugar content even if, at the more advanced stages of ripening, the ratio of acids to sugars tends to be higher, i.e. the relative quantity of fermented sugars is higher. This trend would appear to have its explanation in the lower pH value, for early harvested maize silage, which acts as a limiting factor on bacterial activity.
In the high moisture grain, where the sugar content practically does not vary according to grain moisture, it would
324
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325 appear that the lower fermentative activity of the drier materials should be attributed to the higher cellular osmotic pressure.
CONCLUSIONS
All the results from these trials tend to demonstrate that plant growth rate, yield and forage qualitative characteristics vary with water availability and sometimes with hybrid earliness.
Maximum DM yield is reached 45-50 days after flowering with a forage DM content that ranges from 42% to 38% for irrigated and unirrigated land respectively. Under these latter conditions, the same DM content variation (from 42% to 38%) is observed between early and late hybrids but with a delay of about a week for the former one (the productive peak is reached 52-57 days after flowering).
These trends are mainly due to the variation in the plant component ratios, of which the grain plays the most important role, rather than to DM content in the separate plant components.
These results, together with the forage chemical composition and storage losses, tend to indicate the advantages of harvesting at the maximum crop yield stage, i.e. after the dough stage. However, this does not appear to be advisable for maize silage because of the inevitable qualitative deterioration due to stalk fibre lignification and to the greater amount of undigested grain. In order to give a final judgement on this argument it is necessary to evaluate the real nutritive value of maize silage harvested in various maturity stages in feeding trials.
REFERENCES
Andrieu, M., 1970. Valeur alimentaire du mais-fourrage. Journées d'Information sur le mais plant fourragère, Paris, 27-28 Janvier.
Caldwell, D.M. and Perry, T.W., 1971. Relationship between stage of maturity of the corn plant at time of harvest for corn silage and chemical composition. Journal of Dairy Science, 4, 533-536.
Cántele, A. and Giardini, L., 1966. Variazioni qualitative e quantitative indotte dalla mancata fecondazione nelle pianta di mais. Zootecnica Agricoltura, Veterinaria, 10, 309-326.
326
Cummins, D.G., 1970. Quality and yield of corn plants and components when harvested for silage at different maturity stages. Agronomy Journal, 6, 781784.
Emberger, L., 1933. Revue Générale de Botanique, 45, 473486. Geasler, M., Henderson, Η.E. and Hawkins, D.R., 1967. Effect of stage of
maturity and fineness of chop on yield per acre and feeding value of corn silage. Michigan State University, Report, AHBC666.
Giardini, Α., 1969. L'erbaio di mais in coltura rada e fitta. L'aliment
azione Animale, 3, 121136. Giardini, A. and Toderi, G., 1964. L'Epoca di raccolta dei foraggi per
insilamento in torre. Progresso Agricolo, 2, 171189. Gordon, C.H., Derbyshire, J.C. and Van Soest, P.J., 1968. Normal and late
harvesting of corn for silage. Journal of Dairy Science, Ş1, 1258. Johnson, R.R., McClure, K.E., Johnson, L.J., Klosterman, E.W. and Triplett,
G.B., 1966. Corn plant maturity. I. Changes in dry matter and protein distribution in corn plants. Agronomy Journal, 2, 151153.
Mancini, E., 1940. I problemi tecnici dell'irrigazione dei terreni di piano dell'Emilia e Romagna. Atti del II Convegno Nazionale delle Irrigazioni, Bologna, 2526 maggio.
Nelson, L.V. , Hildebrand, S.C., Henderson, Η.E., Hillman, D., Höglund, CR., Maddox, R.L. and White, R.G., 1969. Corn silage. Production, harvest, storage in Michigan. Cooperative Extension Service.
Owens, M.J., Jorgensen, N.A., Mohanty, G.P. and Voelker, H.H., 1967. Feeding value of high dry matter corn silage. Journal of Dairy Science, 50, 983.
Perry, T.W., Caldwell, D.M., Reedal, J.R. and Knodt, C.B., 1968. Stage of maturity of corn at time of harvest for silage and yield of digestible nutrients. Journal of Dairy Science, 51, 799802.
Pollacsek, M.M. and Caenen, T.G., 1970. Journées d'Information sur le maïs plant fourragère, Paris, 2728 Janvier.
Animal Feed Science and Technology. 1(1976) 327-343 327 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
DISCUSSION ON SESSION 3
E. Zimmer West Germany
The two papers that we are now going to discuss showed the effects of the main factors on, first , the type of fermentation and then on the amount of losses and reduction in energy content - that means the change in nutritive value. This was done in the papers both for whole-crop silage and for high moisture ear corn or high moisture grain. These factors are mainly the stage of maturity or the DM content of the maize plant or ears or grain. Then physical treatment affects particle size and aeration during the filling procedure, during the storage period or during unloading. Physical treatment and aeration means silage technology. From that we are able to estimate what we call unavoidable losses, or the unavoidable changes during fermentation, the minimum biological losses and changes and also as the second paper also showed, the avoidable losses and changes which will sometimes double or even triple the former figure. So, if we follow this general line, we may discuss first, whole crop maize and second the conservation of ears or high moisture grain.
J.B. Kilkenny UK
I ask for further information on the heating process. Firstly, I am interested in the comment in Dr. Zimmer's paper on the effect of urea reducing losses through heating. I would like more information on the chemistry of that reaction. Secondly, I would like some recommendations on what rate of feeding we should be recommending to farmers for silage. In other words, how quickly should farmers be utilising maize silage, in the summer in particular, to reduce these problems of heating?
E. Zimmer
Firstly, heating or so-called 'after-fermentation'. It is not fermentation but a complete mineralisation of organic acids
328 and therefore there is an increase in pH, decrease in acids, and following that, other processes of decomposition. From our knowledge up to now, yeasts are more or less responsible. However, in the last few days, we finished discussion with Dr. Woolford from Hurley who studied at our Institute for six months with Dr. Hönig, the question whether bacteria are also involved in the heating process and we have some data which goes in this direction. However, we need to deal a little more with this problem. The effect of urea we can explain up to now only by stating that urea often gives a more hetero-lactic type of fermentation which means more acetic acid. We know that acetic as well as propionic and butyric has a fungicidal effect. This is our explanation; we did not look more deeply into the details. It was noted in experiments in the Institute as well as in France.
Now the recommendation to farmers is, first of all, to have the right size of silo for the number of animals in the group; the right size of trench or the right size of tower. Then they must ensure quick filling, very good packing and very quick covering of the silo because aeration at the beginning of fermentation causes the risk of heating after storage. These are the old recipes we can give, or they can add some organic acid, but this depends on cost.
H. Hönig West Gerrxv.y
I would like to make some additions to the chemistry of the effect of urea or ammonia in preventing aerobic decomposition when unloading the silo: we found that the effect of Prosil as an ammonia additive was better than that of urea and this indicates that the specific effect of ammonia against those micro-organisms responsible for aerobic deterioration is active at the beginning of the fermentation process at the time of ensiling. The normal lactic fermentation proceeds in ammonia-treated silage but it takes three or four days after opening the silo for the responsible micro-organisms to develop anew. Urea is transformed to ammonia and so its effect cannot be as high as a pure ammonia additive. That is what we found out from these results. For the prevention of aerobic
329
decomposition when unloading the silo, I would want to point out once more the very great effect of good or bad technology. We made comparisons of unloading the silo by rapid tearing out of the material with the front-end unloader, and cutting exact blocks or scraping the silo face with the unloader, and we had a marked difference in the aerobic deterioration. It started in the first case, after the second day and in the other case after three or four days only, and that is enough time for the farmer to use the stable silage. Another finding was that when blocks cut by block-cutting device were put in the feeding area of the cattle-shed they were stable for 7 days. Beside these we put the same material loosened and it heated up after 3 days. This is another hint that keeping the compactness is very, very important to prevent aerobic deterioration.
R.J. Wilkins UK
I would like to support Dr. Hönig strongly in his statement on the key ways of preventing aerobic deterioration. We, like Professor Zimmer, have been involved in some studies of chemical means of control of this process of deterioration but our feeling at the moment is that in most feeding situations it is a matter of management of the ensiling and silage feeding in such a way as to minimise the exposure of the mass to air. We have done some limited experimentation on the effects of non-protein nitrogen additives. In one experiment we found that Prosil, in comparison with propionic acid, did increase aerobic stability. Heating up was delayed by perhaps a day or two more than that of untreated silage but the effect was less than we had obtained with an addition of 0.25% propionic acid on a fresh matter basis. So the results we had are in the same direction as those obtained in Michigan and in Braunschweig and we associated this effect with the lower total viable count of micro-organisms of the Prosil-treated material when it was taken out of the silo, compared with the silage made without additives. In further experiments with propionic acid , our findings would be very similar to those in Germany. To give you a long term stability in aerobic conditions application rates of at least 0.5% propionic acid on a DM basis are needed.
330
This would give you tremendous flexibility in feeding out but it is an expensive procedure. With urea we have no experiments but our observations would not support the finding of an increase in aerobic stability in urea-treated maize silage. This is only a very limited observation.
E. Zimmer
What I was pointing out is that NPN as an additive to add nitrogen has another interesting effect from the standpoint of fermentation and therefore we looked into this stabilising effect against heating. So, we can recommend to farmers that if they add NPN they will have, in addition, this stabilising effect against heating because we know, as Dr. Wilkins said, also under German conditions, adding 0.5% or even 0.7% of propionic acid or acetic is not economic. So we cannot recommend using propionic acid at present. Do we have any other comments on this heating problem or other questions?
R.L. Vetter USA
I have one comment arising from your paper - you are discounting the high penalties of lactic acid fermentation. I believe from our work that lactic acid has a higher energetic efficiency than any other of the dry matter components. When you add urea or Prosil, there is the initial phase which you explained very well and then there is a buffering effect which allows the production of a greater total amount of acids. My question is, are you recommending a procedure which you are saying is reducing the amount of acid production? I wonder if you are not really getting more total acids, If you look at lactic acid as having a higher energetic efficiency, even though you have a slight DM loss, the net efficiency to the animal may be equal to or greater than when you have less lactic acid production.
E. Zimmer
We did not look at this higher energy efficiency; we know
331
by using urea, buffering capacity is increased and therefore we get higher lactic acid content. If you calculate this on an energy loss basis this increase, let me say, of 2 or 4 points on a DM basis compared with a 3.5% energy loss converting sugar to lactic acid means it is within the range of our methods. So, we do not recommend a certain method to increase buffering capacity, under German conditions, as the people from Ohio stated in the early 1950s, but we know the effect of using NPN and therefore we say that this is the effect on fermentation. We did not go into feeding experiments and I am not sure whether this small difference will have an effect on the animals - maybe Professor Kaufmann can give an answer. It is only 4%.
W. Kaufmann West Germany
I would agree with Zimmer; I would not believe that you would find any difference in energy efficiency with a little more lactic acid.
E. Zimmer
I think it is 4% - we go from 10 - 14% or 8 - 12%. This is compared to the whole net energy content; it is a very small change in the composition of carbohydrates. I have not found any new experimental data from the States going the way the Ohio people did in the middle 1950s. Can you give new data Professor Vetter?
R.L. Vetter
Dr. Owens from Oklahoma recently reported on net efficiency although I do not know the data in detail. We are talking here of the conversion of organic matter in the fermentation of silage but that loss versus the loss in the rumen where you have methanogenesis so that you are absorbing lactate.
K.G. Møl le Denmark
A few years ago some firms advised that if you were unlucky
332
and the silage was heating during unloading you could treat it with, for instance, propionic acid, the moment you were aware of the heating. Now, in your paper Professor Zimmer, I find it stated that application to prevent heating has to be done during filling. Does that mean, in other words, that it is not worthwhile for a farmer if his silage is heating, to apply acid in order to try to arrest that heating because some people still think that there is a possibility to do so?
E. Zimmer
This was a wrong recommendation, that is our answer, because if a certain yeast population, or even bacterial population, was built up five months ago then you cannot penetrate enough propionic acid into your trench silo or tower silo to kill them. It is technically impossible. You can penetrate maybe 2 cm, for example.
J.M. Wilkinson UK
My question refers to your Figure 3, Professor Zimmer, where you show the difference in starch equivalent between silage and fresh maize in relation to DM content. Now I can understand the decrease in starch equivalent as a result of fermentation and the loss of the most digestible parts of the plant, the starch content, but I am a bit puzzled as to why the difference between silage and fresh material should get greater, in absolute terms, as DM content increases, because one would expect the extent of fermentation to decrease. Is it because of increased respiration or aerobic deterioration, or what factor?
E. Zimmer
No, I would say that it is because of the mathematical model I had to use to bring together all the available data. Like you, I was astonished by this smaller difference but I could not find another correlation and regression formula for both the data coming from fresh material and other material. So, these data will give only the general tendency here and you
333 cannot take them and say that for 20% DM content, then it is 22.5 starch equivalent difference, and going to another DM content it is exactly the same; it is general tendency. We do not have sufficient experiments comparing those things over the whole period of DM content, of stages of maturity.
W. Kaufmann
There might be a difference between the calculation of starch equivalents and other calculations of energy content, because in starch equivalents there is a calculation from the crude fibre.
E. Zimmer
However, this cannot account for this difference that Dr. Wilkinson has stated.
C. Lelong France
I would agree with your conclusions on the effect of propionic acid during summer when you cut a slice of silage. We try to avoid formation of yeast under the plastic cover and we apply a little propionic acid on the surface there and we find the yeast is decreased to a depth of 10 or 15 cm.
E. Zimmer
This is another picture, of course. As I stated, and Dr. Hönig and Dr. Wilkins agreed with me, good management will prevent the risk of heating. Good management means high density, quick filling to avoid aeration and therefore in the deeper layers of your silo also you can prevent it by its own density, by the covering of the deeper layers by the higher layers. Then you have a special risk to the last layer of the silo and if you add some propionic acid here then you get an additional precaution. There we would agree, However, the question was related to adding propionic acid during unloading when heating had already started and at this stage it is
334 impossible to do it.
C. Lelong
I have another question, to Parigi-Bini, on ear conservation. You had a very low DM content. I agree with you and our conclusion is that it is necessary to ensile ears with only 55 - 60% DM but at 75% of DM it is possible to put cobs in cribs and it is well-known that minimum water content is necessary to get good fermentation.
R. Parigi-Bini Italy
No, I said that when the DM goes higher than 65%, fermentation declines very rapidly.
E. Zimmer
This is a general tendency that with increasing DM in any kind of crops we have to ensile, we decrease the activity of our micro-organisms and stabilise fermentation in terms of the proportion of lactic acid to volatile fatty acids. Then, of course, we increase pH, but pH and dry matter content are closely correlated. It is not inevitable that more yeast develops with a higher DM content, if the management is good.
C. Lelong
The production of ear silage is very difficult beyond 65% DM.
R. Parigi-Bini
However, in several years, in some weather conditions in Italy, we have been obliged to collect ears at more than 70% DM. The dry matter of our crop is going up, more than 1% in the entire plant per day in the particular weather conditions, when we have sun and also wind^and the dry matter goes very high in just two or three days. This is why in my conclusion I say, 'when not imposed by climatic conditions'. In the real conditions
335
of the farm you do not have time to collect more quickly. In a few days, in our conditions in Italy, the DM in the crop goes up very rapidly.
E. Ζ immer
This question from Mr. Lelong changed to the second paper. May I ask you to finish the discussion on the first paper if there are any other questions.
D. Lanari Italy
I would like to ask you a question. Professor Zimmer, relating to your Table 3, 'Effect of Chopping Treatment on Maize'. I am interested in the figures you report of the percentage of DM in faeces. Did you measure the overall digestibility or just measure the amount of DM that you collected by washing faeces and looking at the grain content?
H. Httnig
Grain losses in the faeces are determined as follows: we freezedry a sample of faeces, then sort out the grains and calculate the amount of dry matter weight of grains in relation to the dry matter weight of grain in the feed. In addition we have analysed the material of the grains sorted out from the faeces and found that they were practically of the same value as the grains going into the rumen.
The relationship between the whole grain eaten and the grain not digested was about 20% for high dry matter maize and only 10% for material harvested at an earlier stage with a dry matter content of 25 30%.
D. Lanari
Did you run digestion trials?
336 H. Hönig
We did not.
Lanari
I am thinking that probably you do not find such a big difference in organic matter digestibility between maize silage which is reçut and that which is not reçut after unloading.
E. Zimmer
Because of some digestion of the kernels?
D. Lanari
Because, probably, there is the same kind of losses, there is no advantage in recutting after unloading.
F. de Boer Netherlands
I have a question on one detail of your statement in your paper on NPN additives. You mention that, in Germany, urea and the combination of minerals with urea is in common use. Now, I am curious to know how many ha of your maize silage are made with this 'Maisfertil' because in our conditions which are more or less comparable, it is only about 1% of all silage which is made with this urea/mineral mixture. When you say 'in common use' do you mean IO, 20, 30% of your silage is made in this way?
No, not such big amounts. Common use means well-known and used, but I cannot give a figure for 'Maisfertil' because it is a fairly new product. All the farmers know it very well, they know the advantages and disadvantages but I cannot give a percentage of the total acreage.
337
D. O o s t e n d o r p Netherlands
Can you say a little more about the way in which these products are added to the silage? What type of applicators are used?
E. Zimmer
There are applicators which are used for adding other silage additives mounted on the forage chopper. It is applied during the chopping of the material. For the liquid Prosil we do not have a really good method of application. This is still under experimentation and is a real problem. However, for urea or 'Maisfertil' it is not a technical problem, you can buy the machine.
H. Schneeberger Switzerland
I would like to come back to the question of the grain in the faeces. Has somebody more information of differences existing between sheep and cattle or between beef cattle and dairy cattle? We found in the same silage given to beef cattle and to cows that the percentage of grain in cow faeces waá much higher than in beef cattle.
W. Kaufmann
I think there are probably some papers where you can get the answer but it is probably related to the higher rate of intake. Normally beef cattle have a lower intake.
E. Zimmer
Even if you base your data on the same intake you have a different relationship for sheep and for cattle?
W. Kaufmann
That is quite another question, yes. It is about 4%, 3%
33«
difference between sheep and cattle, lower in sheep.
R.J. Wilkins
One of the points in your paper that has not been discussed yet is the question of freezing and its subsequant effects on composition and silage quality in that you have drawn attention to work where you have had both humid and dry conditions after freezing and draw a conclusion that substantial losses occur in DM and in digestibility or nutritive value. In Britain, it has been very common to ensile material weeks after freezing . In some situations we have perhaps welcomed frost as an agent for increasing somewhat the DM in the material. I am not aware of experiments in England that have looked critically at effects on composition but in two animal feeding experiments that I have undertaken myself, both involved in feeding sheep on silage which has been made from maize after different stages of development, and we have had perhaps one cut before frost and then two cuts afterwards, we have not found any major differences in fermentation in the silo. The later material harvested at a rather higher DM content had rather less fermentation, and we have not found major differences in intake or digestibility. I would like your further comments, or other people's comments, on this. I would agree, certainly, that if you have got a crop that is frosted you are more liable to be losing material physically during the harvesting operation and that your recovered DM yields are likely to be reduced.
E. Zimmer
There is very little information on this. If you look in the paper you will find only three or four publications. We do not have experiments of our own dealing with this question but we feel that we have to do it in the near future to look more precisely at the things going on. However, from looking into the farm situation it seems to us that a higher amount of poor fermentation, which is uncommon for maize because normally you have only good fermentation quality, is found after harvesting the maize late in autumn, after freezing. There are
339
a few observations that the epiphytic flora will change so that there are more proteolytic bacteria, more coli, and so on. So this, together, gives a picture of a certain degree of risk but nobody can give a certain answer and I could not find more details. We have to look at these particular conditions, because, in the northern parts of Europe, they are normal.
C. Lelong
Andrieu has some information on the sugar content of normal plants and frosted plants. In normal plants the sugar content is about 18% at the milk stage. Three weeks after frost the average content was 5.9 - 6% of sugar. Five weeks after freezing it was only 2% of sugar. This will be an explanation of your prediction.
R.H. Phipps UK
We have also noted that the mineral composition of the crop after freezing (I assume you mean a hard frost) has decreased markedly and also, obviously, the vitamin A content of the crop would be decreased considerably. We have got some information indicating a decrease in the digestibility of the crop after frosting.
E. Zimmer
We must now discuss the second paper, dealing with the ensiling of high moisture ears and high moisture grain. One aspect has already been discussed. Are there any questions or comments? From our own experiments, reported in Paris in 1973, we are in total agreement with Parigi-Bini's findings, the general tendency of increasing DM and all the other aspects.
R. Parigi-Bini
After sending in the paper for this Conference, I read in a recent number of the Journal of Animal Science, the paper of an Oklahoma State University worker which was quite
340 interesting. It was concerning the physical form of high moisture corn. They measured fermentation in the high moisture corn, ground or entire kernels, and found that fermentation was increased and the degradation of nitrogen components of the grain was more intensive in the ground form than in kernels.
E. Zimmer
I think this fits into the general picture that disintegration of cells will increase the microbial activity because there is more substrate immediately available.
C. Lelong
In France we have seen dry matter losses in big silos on farms which are,for whole plant silage, 15%; for ear silage about 8%; and for grain, high moisture and ground grain, about 4 - 5%.
R. Parigi-Bini
What is the DM content of your ear silage?
C. Lelong
It is 55 - 80%, and for grain, about 30 - 35% because below this moisture content it is quite impossible to manage the silo during summer because fermentation increases quickly during summer when there is a low content of water.
R. Parigi-Bini
Concerning ensiling losses I think the best measure of the losses must be made in big silos. I think the buried bag technique is not so exact especially with a product having a high DM content because you can have a good idea with a good crop silage or also with very high moisture corn or ears because there is more fermentation and also you can measure the losses.
341
Β.G. Cottyn Belgium
May I ask Dr. Parigi-Bini for some more details about the technique of buried bags to determine the percentage losses?
R. Parigi-Bini
It is just a digestibility trial inside the silo. You put a weighed quantity of material in a plastic bag but you do not seal it.
E. Zimmer
In a net.
R. Parigi-Bini
You put several kg of fresh material when you make the silo and when you open the silo you take the bag out.
B.G. Cottyn
Have you made comparisons with the classical technique of weighing in and out to determine losses?
R. Parigi-Bini
No. I measure losses just by the buried bag technique; I have no personal experience of comparisons of the two but in my opinion when using materials of high DM content it is better to weigh the whole quantity.
E. Zimmer
If you want to look in more detail at the conditions of a particular region of the silo this buried bag method is a very good one. If you have enough samples with the buried bag method there should not be a difference between the total input/output balance and the buried bag input/output balance.
342 R.L. Vetter
I should try to clarify some of the Oklahoma work, In the USA much of our high moisture grain is put into vertical silos and in looking at that type of storage versus the trench or bunker silo (which I am sure you are using more) the data favour consistently, in many trials, storage in whole grain form and then rolling the grain prior to feeding but with maize moisture in the range of 22 - 30% the process is basically one, in the initial phases, of germination preceding fermentation. Most of the data pooled from the trials show a consistent performance advantage to storage as Whole grain, provided that it is in an upright silo with a good structure. In a horizontal structure compaction is necessary, by rolling or crushing the grain before it is ensiled. With high moisture grain or reconstituting grain like milo, particularly, there is an improvement by reconstituting to a high moisture level in the whole form and then rolling before feeding. This aspect should be distinguished here because the data in the USA are very consistent with that type of processing.
C. Lelong
What is the effect of conservation time on losses?
R. Parigi-Bini
These experiments have been conducted in a fixed time.
C. Lelong
I thought whole plant silage gave this information.
E. Zimmer
From measuring C0„ production over a long period we know that if we have stable conditions, CO., production is near zero. If we have some leakage we have an increase, and under sub-
343
optimal conditions, or farm conditions, we have an increase and this is then 1% DM or even 2% DM per month. This seems to us a general rule for all the crops we have.
345
SESSION IV
NUTRITIVE VALUE FOR BEEF CATTLE OF DIETS BASED ON THE MAIZE CROP
Nutritive value of different forms of the maize crop: voluntary intake; digestibility; utilisation of nutrients; rate of growth of cattle; efficiency of feed conversion,· metabolic disorders. Effects of type of conservation and processing; pattern of fermentation; additives; supplements of energy, protein, NPN and alkali.
a) Effects of type of diet on energy intake and growth rate Chairman: T. Cobic
b) Nitrogen metabolism and research techniques Chairman: W. Kaufmann
c) Utilisation of dietary energy Chairman: W. Kaufmann
Animal Feed Science and Technology. 1 (1976) 347367 3 4 7 Elsevier Sdentine Publishing Company, Amsterdam Printed in The Netherlands
MAIZE SILAGE WITH OR WITHOUT NPN, DEHYDRATED WHOLECROP' MAIZE PELLETS OR HIGH MOISTURE MAIZE GRAIN FOR FINISHING BULLS*
Ch. V. BOUCQUE, B.G. COTTYN and F.X. BUYSSE National Institute for Animal Nutrition, Β 9231 Gontrode, Belgium.
ABSTRACT
The chemical composition, digestibility and feeding value of 11 lots of maize silage, 11 lots of dehydrated wholecrop maize pellets and 4 batches of high moisture corn have been studied. Digestibility (determined with wethers) and net energy were generally higher for the maize silages than for the dehydrated pellets.
Beef production experiments were carried out over 3 consecutive years with 170 young bulls, to study the influence of method of conservation and the height of cutting on animal performance and on the output of beef per ha. Five basic feedstuffs were given ad libitum: silage from maize cut at 15 cm and at 35 cm above ground level, pellets of dehydrated wholecrop maize which was cut at 13 cm and at 40 cm above ground level, and high moisture maize grain treated with propionic acid. Each group was supplemented with the same protein rich concentrate (19% DCP) at 1% of liveweight. The daily liveweight gain was significantly higher (1431 g/day) for the animals receiving high moisture grain than for those fed with maize silage or maize pellets. The utilisation of the dry matter of the maize silages was more efficient than of the dehydrated maize pellets. The dressing percent and the feed cost price were also in favour of the maize silage rations.
The highest beef output per ha of maize was obtained with the silage and the pelleted maize harvested at the lowest height of cutting.
A second beef production experiment was carried out with 83 young bulls over 2 years to study the effect of NPN addition to maize just prior 'to ensiling. From the preliminary results it can be concluded that the addition of 0.5% urea (Rumipec) or * Communication no.355 of the Institute
348 1.9 to 2.4% Pro-Sil (16.6% NH3) to the silage or plant protein in the concentrate resulted in a significant increase in daily gain and dressing percent compared with the negative control. No difference could be observed between the urea, the NH3 treatment and the positive control for the entire fattening period.
INTRODUCTION
Maize can mainly be used in 3 different forms as a basic feed for beef cattle: silage, dehydrated whole-crop maize pellets and high moisture grain. This paper reports:
a) trials with sheep to determine the digestibility of maize silage, dehydrated whole-crop maize pellets and high-moisture maize. b) beef production trials in which the 3 different forms of the maize crop were fed åd libitum as the basic feed to young bulls. For the silage and for the pellets, the maize plants were cut at 2 different heights above ground level (15 cm and 35-40 cm). For the different systems of harvesting and storing, animal performance was studied and the output of beef per ha was calculated. c) beef production trials with young bulls to study the utilisation of NPN sources in maize silage (provisional results; experiments still in progress).
CHEMICAL COMPOSITION, DIGESTIBILITY AND FEEDING VALUE OF MAIZE SILAGE, DEHYDRATED WHOLE-CROP MAIZE PELLETS AND ROLLED HIGH MOISTURE MAIZE
The digestibility of the different feeds of the maize crop given to fattening bulls during the last 10 years, has been determined with sheep.
The digestion trials were always carried out with 4 wethers fed at the maintenance level; faeces were quantitatively collected and sampled twice a day during a 10-day period.
In total, 11 lots of maize silage, 11 lots of dehydrated maize pellets and 4 lots of rolled high moisture grain have
349
been studied. The maize for silage (Anjou 210) was grown at the Institute and harvested at different stages of maturity varying from the early milk stage (1972) to the dough dent stage. In 1970, 1971 and 1972 two different heights of cutting were applied: 15 cm and 35 cm above ground level. The maize was finely chopped and preserved in trench silos without additives. The dehydrated wholecrop maize pellets were purchased from different commercial drying plants (10 lots from Belgium and 1 from France). The 4 lots of high moisture grain were purchased at a large crop farm, treated with 1.2 to 2.0% propionic acid and stored as whole grain in open concrete silos until the end of the beef production trials. The added percentage of propionic acid varied depending on the moisture content of the grain and the time of storage; the grain was rolled prior to feeding.
The chemical composition, the digestion coefficients and the net energy content of the maize silages, the maize pellets and the high moisture grain are presented in Tables 1, 2 and 3. The starch equivalent was calculated by the method of Kellner and Becker (1971); for the maize pellets a deduction factor of 0.44 per percent crude fibre was applied. The maize silages and the pellets are classified on the basis of their crude fibre content.
The 11 maize silages were characterised by a large diversity in dry matter content (17.6 to 28.2%), in crude fibre content (16.3 to 26.7% in the DM) and in the Nfree extract content (48.5 to 63.5% in the DM). For these silages, harvested in different years, significant relationships (P <0.0l) could be calculated between the crude fibre content and the digestibility of the organic matter (r = 0.78**) or the digestibility of the Nfree extract fraction (r = 0.89**). Demarquilly (1969), Andrieu and Demarquilly (1971) and Aerts et al. (1976) Obtained a nearly constant digestibility for maize harvested between the milk stage and the mature stage (24 to 30% dry matter).
The net energy content of the silages (y = starch equivalent) was negatively related to the crude fibre content (x): y =1.17x + 87.68; r = 0.90**; Ρ <0.01.
For the 11 lots of dehydrated wholecrop maize pellets no significant relation could be established between the
TABLE 1 CHEMICAL COMPOSITION, DIGESTIBILITY AND FEEDING VALUE OF MAIZE SILAGE
Year of harvest
1972b ! 1972a { 1974 1973 1973 1971 1971a 1974 1970a 1971b 1970b
flean
Í SD
Dry matter (%)
17.6 19.4 22.5 23.2 26.5 22.1 24.4 27.4 25.1 26.3 28.2
23.9
3.3
Composition of
Organic matter
92.2 91.8 93.2 93.0 93.1 93.7 92.9 93.8 93.7 93.9 94.0
93.2
0.7
Crude protein
11.1 10.7 8.8 9.2 9.6 8.6 9.0 8.6 9.2 9.4 8.8
9.4
0.8
the dry matter (%)
Crude fibre
26.7 26.6 22.7 21.5 21.3 20.8 20.5 18.5 18.3 17.5 16.3
21.0
3.4
Ether extr.
4.7 5.9 3.4 4.5 4.7 4.6 4.4 3.5 6.8 3.5 6.9
4.8
1.2
N-free extr.
49.7 48.5 58.3 57.8 57.5 59.7 59.0 63.2 59.4 63.5 62.0
58.0
4.9
Dry matter
61.0 62.4 69.7 70.4 67.0 64.9 70.3 69.9 71.0 69.0 70.9
67.9
3.6
Digestion coefficients
Organic matter
64.6 66.0 73.1 73.7 69.9 68.6 73.7 72.7 74.0 71.8 73.6
71.1
3.3
Crude protein
55.7 54.3 58.7 63.1 58.2 35.4 58.3 58.7 61.2 59.3 53.3
56.0 ·
7.4
Crude fibre
68.2 67.3 68.7 68.5 61.9 60.6 66.9 63.5 63.3 56.5 57.5
63.9
4.4
(%)
Ether extr.
77.6 84.7 75.2 82.5 81.2 81.0 83.0 81.5 88.3 79.6 88.0
82.1
4.0
N-free extr.
66.1 65.5 76.9 76.7 73.9 75.2 77.8 76.8 77.6 77.4 79.1
74.8
4.7
Starch equivalent
(% DM)
55.6 56.5 63.1 64.9 61.6 61.0 65.4 64.7 68.8 64.5 69.5
63.2
4.4
a = Maize harvested at 15 cm above ground level; b = 35 cm
TABLE 2 CHEMICAL COMPOSITION, DIGESTIBILITY AND FEEDING VALUE OF DEHYDRATED WHOLECROP MAIZE PELLETS
Year of har
vest
1967 l?72b 1972a 1968 1970b 1971 1971b 1970a 1971a 1969 1971
Mean
+ , SD
Dry mat
ter (%)
88.0 84.8 88.2 90.5 88.6 91.8 86.1 90.6 91.6 88.9 89.7
89.0
2.2
Compo
Organic matter
88.1 05.1 95.3 94.8 95.3 95.4 94.3 94.4 96.4 95.3 95.2
94.5
2.2
sition of
Crude protein
14.6 8.0 8.5 8.7 8.1 7.7 7.5 8.4 8.0 8.9 9.1
8.9
1.9
the dry
■Crude fibre
21.8 20.6 19.2 17.7 17.1 16.7 16.7 16.5 14.7 14.3 14.1
17.2
2.5
matter
Ether extr.
4.4 3.3 2.9 3.5 2.6 3.1 3.2 3.1 3.2 3.6 3.0
3.3
0.5
(%)
Nfree extr.
47.3 62.3 64.7 64.9 67.5 67.9 66.9 66.4 70.5 68.5 68.9
05.1
6.3
Dry matter
61.8 66.1 70.4 61.4 61.0 62.8 65.7 66.9 69.8 69.9 70.3
66.0
3.8
Digestion coefficients
Organic matter
64.6 67.8 71.9 63.4 63.4 64.6 68.7 69.4 71.2 72.9 72.4
68.2
3.7
Crude protein
59.9 39.4 44.5 48.3 38.2 28.9 49.8 52.2 50.7 59.8 58.7
48.2
9.8
Crude fibre
57.0 58.6 61.7 37.0 40.2 38.7 51.2 48.1 46.0 46.9 49.8
48.7
8.1
Ui
Ether extr.
69.1 76.1 66.6 77.7 71.9 67.3 70.7 75.0 76.0 84.5 82.5
74.3
5.9
Nfree extr.
69.0 74.4 79.3 71.8 72.0 74.8 75.7 76.6 78.6 79.5 78.4
75.5
3.5
Starch equi
valent (% DM)
49.6 57.4 61.9 54.6 54.5 56.0 59.7 60.1 64.2 65.7 64.6
58.9
5.0
a = Maize harvested at 15 cm above ground level; b = 35 cm
TABLE 3 CHEMICAL COMPOSITION, DIGESTIBILITY AND FEEDING VALUE OF ROLLED HIGH MOISTURE GRAIN
Year of harvest
1970 1971 1973 1974
Mean
+ - SD
Dry matter U)
66.3 65.3 62.0 64.3
64.5
1.8
Compo
Organic matter
98.0 98.3 98.2 97.6
98.0
0.3
sition of
Crude protein
10.8 9.7 9.1 10.5
10.0
0.8
the dry
Crude fibre
1.9 1.9 2.4 2.0
2.0
0.2
matter
Ether extr.
5.0 3.9 3.7 2.9
3.9
0.9
(*)
N-free extr.
80.3 82.8 83.0 82.2
82.1
1.2
Digestion coefficients (%)
Dry matter
90.6 87.7 89.7 91.4
89.9
1.6
Organic matter
90.9 88.6 90.5 93.1
90.8
3.4
Crude protein
74.6 60.5 65.8 70.8
67.9
6.1
Crude Ether fibre extr.
83.8 78.1
33.2 85.5 88.8
84.1
4.5
N-free extr.
94.3 93.9 95.2 96.5
95.0
1.2
Starch equivalent (% DM)
95.9 92.4 95.0 93.9
94.3
2.3
353 crude fibre content and the digestibility of the organic matter. The digestibility of the N-free extract fraction (y) was negatively correlated with the crude fibre content (x): y = -0.91x + 91.07; r = -0.65*; P<0.05. The gradual decrease of the crude fibre content (x) resulted in a significant increase in the starch equivalent (y): y = -1.51x + 84.95; r = -0.75**; P<0.01. Earlier digestibility trials with maize pellets were already published by Cottyn (1969) and Cottyn et al. (1973).
When the maize silages are compared with the dehydrated maize pellets, the digestibility of the organic matter and the starch equivalent content are generally lower for the pellets than for the silages. Especially when only the 8 silages and the 8 batches of pellets are compared, having a crude fibre content with the 16.3 - 21.8% range (Tables 1, 2 and 4), the differences in digestibility coefficients and in the net energy content are more pronounced in favour of the maize silages. This is in accordance with results of Béranger and Marchadier (1970) and Demarquilly and Andrieu (1970). The highest depression occurred in the digestibility of the crude fibre fraction: the mean coefficient decreased from 62.3 (for the 8 silages) to 49.1 (for the 8 lots of pellets). Demarquilly (1971), Dijkstra et al. (1971), Malterre et al. (1971), Zgajnar (1972) and Cottyn et al. (1976) obtained similar results. The dehydration process at high temperatures has also reduced the digestibility (especially of the protein) of other crops such as grass (Knutsson et al. 1973) and lucerne (Saunders et al. 1973).
The net energy expressed in terms of starch equivalent in the dry matter is highest for the high moisture grain owing to its high content of highly digestible N-free extract fraction (Table 3). The variation in net energy content of the 4 lots of maize grain is much smaller than for the maize silages and the dehydrated maize pellets.
354
TABLE 4
COMPARISON BETWEEN MAIZE SILAGES AND DEHYDRATED WHOLECROP MAIZE PELLETS HAVING A CORRESPONDING CRUDE FIBRE CONTENT ( 1 6 . 3 t o 21.8«. i n t h e DM)
(Means + s t a n d a r d d e v i a t i o n )
Number of lots Dry matter Organic matter Crude protein Crude fibrr Ether extract Nfree extract Starch equivalent Digestible crude protein
Chemical sition (>
Silage
8 100*
9 3.=; + 0.4 9.0 + 0.4 19.3 + 1.9 4.9 + 1.3
60.3 + 2.3 65.1 + 3.0
5.1 + 0.9
compo
DM)
Pellets
8 100*
91.1 + 2.5 o.o + 2.3 18.3 + 2.0 3.3 + 0.5
63.5 + 6.8 56.7 + 3.9
4.2 + 1.9
Digestion coefficient ( .)
Silage Pellets
8 8 6 1 . 2 + 2 . 2 64.5 +3.3 7 2 . 3 + 2 . 0 6 6 . 7 + 3 . 2 55.9 + 8.8 45.2 + 9.6 62.3 + 4.2 49.1 + 9.6 83.1 + 3.3 71.8 + 4.1 76.8 + 1.6 74.2 + 3.2
* Mean DM c o n t e n t : 25.4« for the 8 s i l a g e s and 88.6% for t he 8 p e l l e t s
MAIZE SILAGE, DEHYDRATED WHOLECROP MAIZE PELLETS OR ROLLED
HIGH MOISTURE GRAIN AS BASIC FEED FOR YOUNG FATTENING BULLS
Experj j t ie inţa^l
D u r i n g t h r e e y e a r s ( 1 9 7 0 , 1 9 7 1 a n d 1972) b e e f p r o d u c t i o n
t r i a l s w e r e c a r r i e d o u t w i t h 1 7 0 b u l l s t o s t u d y t h e u t i l i s a t i o n
o f 3 d i f f e r e n t f o r m s o f t h e m a i z e c r o p : s i l a g e , d e h y d r a t e d
w h o l e c r o p m a i z e p e l l e t s a n d h i g h m o i s t u r e g r a i n . F o r t h e
s i l a g e a n d f o r t h e p e l l e t s , t h e m a i z e c r o p w a s c u t a t 2
d i f f e r e n t h e i g h t s a b o v e g r o u n d l e v e l (15 cm a n d 35 c m ) . The
m a i z e f o r s i l a g e ( A n j o u 2 1 0 ) was g r o w n a t t h e I n s t i t u t e a t
G o n t r o d e a n d h a r v e s t e d a t t h e d o u g h d e n t s t a g e e x c e p t i n 1972
when t h e c r o p h a r d l y r e a c h e d t h e m i l k s t a g e b e c a u s e o f t h e b a d
c l i m a t i c c o n d i t i o n s i n t h a t s u m m e r . The d e h y d r a t e d w h o l e c r o p
m a i z e p e l l e t s w e r e p u r c h a s e d f r o m a c o m m e r c i a l d r y i n g p l a n t ;
t h e m a i z e was a l s o c u t a t t w o d i f f e r e n t h e i g h t s a b o v e g r o u n d
l e v e l (13 cm a n d 40 c m ) , c h o p p e d t o a maximum l e n g t h o f 2 cm,
d e h y d r a t e d , h a m m e r m i l l e d a n d p e l l e t e d .
355 The high moisture grain was treated with 1.2 to 2.0%
propionic acid and preserved as whole grain in open concrete silos until the end of the feeding trials. The grain was rolled prior to feeding.
Each of the 5 basic feeds (2 silages, 2 pellets and 1 high moisture grain) was given ad libitum and supplemented with a protein rich concentrate (19% DCP) at 1% of liveweight. Straw was always available in the hay rack. The feeding value of the different feeds is shown in Table 5.
TABLE 5 MEAN FEEDING VALUE OF FEEDS (% of DRY MATTER)
Experimental year
1970-71
1971-72
1972-73
Height of cut
DM* DCP CF SE
DM DCP CF SE
DM DCP CF SE
Maize silage
15 cm
24.4 5.8 18.9 68.5
24.4 4.3 20.8 62.8
18.8 5.9 29.3 56.4
35 cm
26.6 5.2 16.4 68.4
25.8 5.9 18.3 62.9
18.7 5.9
27.8 57.2
Dehydrated maize pellets
13 cm 40 cm
91.2 89.6 4.4 3.1 16.6 17.4 59.8 54.0
89.3 87.8 4.4 3.0 16.3 17.3* 62.2 59.5
87.7 87.9 3.9 3.4 19.6 20.0 61.5 57.8
High moisture grain
62.5 6.5 1.1 94.6
68.2 6.5 1.6 91.8
55.9 6.1 3.0 91.6
Concentrate
85.5 22.9 6.6 77.1
84.4 21.6 6.6 77.3
85.0 22.6 7.3 78.6
DM = dry matter content; DCP = digestible crude protein in the DM; CF = crude fibre in the DM; SE = starch equivalent in the DM
The experiments were c a r r i e d out with young s t o r e b u l l s (150 of the whi te -b lue and 20 of the whi te - red breed of Belgium), purchased a t the end of the grazing season. After a p r e -experimental per iod of 10 weeks the animals were d iv ided a t random i n t o groups of 7 t o 8 i n d i v i d u a l s ; 122 b u l l s were
356 fattened in loose houses and 48 were individually tied up; they were all bedded on straw.
Results and discussion The maize silages cut at 35 cm (Table 5) were generally
characterised by a higher dry matter, a lower crude fibre and a higher N-free extract content compared with the silages cut at 15 cm. Andrieu and Demarquilly (1971) and Cordiez et al. (1971) reported similar differences. That v/as not the case in 1972 because the maize was harvested in the milk stage. In this year the height of cutting did not influence considerably the digestibility of the organic matter and the N-free extract fraction of the silages, so the net energy values were similar. For the dehydrated maize pellets it cannot be guaranteed that the different height of cutting was applied simultaneously at the same stage of maturity; nevertheless, there was a difference in composition and in feeding value of the 6 lots of pellets.
The mean daily growth rates for the 5 rations varied between 1142 and 1431 g (Table 6). The daily liveweight gain obtained with high moisture grain v/as significantly higher (P<0.01) (Duncan, 1955) than with both maize silages and dehydrated maize pellets. Geay and Liénard (1971) obtained an even higher weight gain (1539 g/day during an experimental period of 139 days) with 12 bulls fattened with high moisture grain between 356 and 570 kg liveweight. Dexheimer et al. (1971) , Miller et al. (1971) , Forsyth et al. (1972) , Self and Hoffman (1972) and Wilson et al. (1972) also obtained good results with fattening steers fed on high moisture grain or on artificially dried grain. The mean daily liveweight gains obtained with the different batches of dehydrated maize pellets are significantly different (P 0.05); this is due to the difference in digestibility and net energy content. In spite of a higher dry matter intake per day and per kg metabolic weight for the two rations of maize pellets compared with the two silage rations, the liveweight gain was not significantly different. We calculated a significant regression equation (Figure 1) between daily gain (y) and net energy intake/kg W 0 · 7 5 (x).
357 TABLE 6 PERFORMANCE OF BULLS FATTENED WITH MAIZE SILAGE, MAIZE PELLETS AND HIGH MOISTURE GRAIN (MEAN VALUES OF 3 EXPERIMENTS AND STANDARD ERRORS OF THE MEANS)
Basic feedstuff
Height of cut (cm)
Number of bulls (groups) Initial liveweight (kg) Final liveweight (kg) Experimental days Daily liveweight gain (g)
Daily feed intake (kg) - concentrate - maize silage - maize pellets - high moisture grain - dry matter - digest, crude protein - starch equivalent
Daily intake(g/kg W0·75) - dry matter - digest, crude protein - starch equivalent
Intake/100 kg liveweight (kg) - dry matter - digest, crude protein - starch equivalent
Feed conversion (kg) - concentrate - maize silage - maize pellets - high moisture grain - dry matter - digest, crude protein - starch equivalent
Slaughter data (%) - weight loss after 20h fasting
- dressing out
Feed cost price!**) (BF/kg gain)
Maize
13-17
39 (5) 277.5 565.5 245.7 1172ab
+24.8
4.05 17.68 --7.44 0.985 5.16
80.0 10.6 55.5
1.77 0.234 1.22
3.45 15.08 --6.35 0.840 4.40
2.30a +0.13 63.21a +0.30
35.7
silage
33-38
39 (5) 278.7 565.9 240.6 1194ab
+21.4
4.05 17.66 --7.54 1.017 5.23
81.0 10.9 56.2
1.79 0.241 1.24
3.39 14.79 --6.32 0.852 4.38
2.48a +0.16 63.24a +0.31
35.8
Maize pellets
10-15
36 (5) 278.4 575.3 241.8 1228a<*> +25.8
4.11 -5.59 -8.47 1.004 5.78
90.2 10.7 61.6
1.98 0.235 1.35
3.35 -4.55 -6.90 0.818 4.70
2.30a +0.14 62.51a +0.31
45.7
38-40
36 (5) 278.1 558.3 245.4 1142b +21.1
4.07 -5.30 -8.12 0.935 5.38
87.9 10.1 58.2
1.94 0.224 1.29
3.56 -4.64 -7.11 0.819 4.71
2.34a +0.15 61.71b +9.35
49.9
High moisture grain
20 (3) 275.6 563.7 201.4 1431c +34.8
4.04 --7.08 7.38 1.Ö97 6.29
79.6 11.8 67.9
1.76 0.261 1.50
2.82 --4.95 5.16 0.767 4.40
2.93t +0.14 63.10a +0.44
44.9 (*) Means on the same line bearing different superscript letters differ
significantly at P<0.05 or 0.01 (Snedecor and Cochran, 1967; Duncan, 1955).
(**) Unit price per kg feed: 0.65 BF and 0.7 BF for the 2 silages; 4.5 BF and 5.0 BF for the 2 maize pellets; 4.3 BF for the high moisture grain (65% DM); 7.5 BF for the concentrate.
358
1500
1400
1300
1200
1100
1000
DAILY GAIN (g)
y = 17,85X + 166,5 r = 0 ,87* *
oMAIZE SILAGE ■ DEHYDRATED MAIZE PELLETS • HIGH MOISTURE CORN
INTAKE (g)S.E. /Kg W0·
7 5
50 55 60 65 70 75
Figure 1 Daily gain related to net energy intake
In accordance with most of the French authors (ITCF, 1970a , Lelong and Fekete, 1971 and Malterre et al. 1971), the feed efficiency of maize silage was higher than that of maize pellets. Even when the daily gain was sometimes slightly higher for the rations of maize pellets (such as reported by Marchadier, 1970), the dry matter and calculated starch equivalent intake per kg liveweight gain was lower for the maize silage rations compared to those of maize pellets. The dressing percentage and the feed cost price were also in favour of the maize silage rations.
From the mean levels of liveweight gain (Table 6) and the mean yields obtained in 1970, 1971 and 1972 (Table 7) we calculated that between 8.7 and 9.6 bulls per ha can be fattened
359 from 275 to 575 kg liveweight when dough-dent maize is ensiled or dehydrated. With high moisture grain, only 6.1 bulls can be fed per ha.
For both methods of conserving the whole-crop maize (silage or dehydration) the lower height of cutting gave a higher output of beef per ha. The net energy content together with the output figures per ha show that additional yield rather than superior energy content was the major factor contributing to the improved output of beef per ha.
TABLE 7
BEEF PRODUCTION PER HA OF MAIZE (MEAN YIELDS 1 9 7 0 + 1 9 7 1 + 1972 ) ( 1 7 0 BULLS, LIVEWEIGHT INTERVAL: 2 7 8 - 5 6 6 kg)
Basic feedstuff
Height of cut (cm)
Yield (kg/ha) Dry matter content (%) Dry matter yield (kg/ha)
Useful feed - percent - kg feed/ha
Feed conversion (kg) Kg liveweight gain/ha Kg concentrate supplement/ha
Maize
13-17
54 200 22.6
12 250
77.7 42 113
15.1 2 789
9 622
silage
33-38
47 7C0* 23.9
11 4GC
81.4 38 828
14.8 2 624
8 8?5
Maize pellets
10-13
(89)
12 250
95 13 076
4.55 2 874
9 628
38-40
(89)
11 400
95 12 169
4.64 2 623
9 338
High moisture grain
8 000 (65)
5 200
97.5 9 068 (55.8% DM) 4.95 1 836
5 178
* Maize harvested between 33 and 38 cm yielded on average 12% less than maize cut between 13 and 17 cm.
COMPLETE DRY RATIONS FOR INTENSIVE BEEF PRODUCTION BASED ON DEHYDRATED WHOLE-CROP MAIZE PELLETS
Complete r a t i o n s i n c l u d i n g d e h y d r a t e d ma ize p e l l e t s from 0 t o 70% i n compar i son w i t h r o l l e d b a r l e y o r w i t h g round ma ize g r a i n have been s t u d i e d w i t h 41 and 72 young f a t t e n i n g b u l l s (140 - 490 kg l i v e w e i g h t ) r e s p e c t i v e l y . The r e s u l t s have
360 already been published by Boucqué et al. (1971) and Boucqué et al. (1973).
MAIZE SILAGE WITH OR WITHOUT NPN SOURCES AS BASIC FEED FOR YOUNG FATTENING BULLS (PRELIMINARY RESULTS)
Experimental Because the protein content of maize silage is low, the
addition of NPN sources to the silage can be a valuable supplement to this high energy feed. During 1973 and 1974 two sources of NPN were added to doughdent maize (Anjou 210) just prior to ensiling: ProSil (2.39% in 1973 and 1.94% in 1974 added to the fresh mass) and Rumipec at 1% added. Each year control maize silage which received no additive was stored in trench silos. Rumipec is a dry granulated commercial product composed of urea (50%), minerals (5.2% P, 10% Ca, 2% S, 2% Mg) and microelements (Fe, Zn, Mn, I, Co). ProSil is an ammoniamineral suspension developed at Michigan State University containing 85% crude protein equivalent (16.6% NH3), 9% molasses, 4.3% Ca, 1.5% Ρ, 1.3% S, 3.2% Na, 12.2% Cl and traces of Zn, Cu, Mg, I and Co (Henderson and Britt, 1974).
The beef production experiments were carried out with 4 groups of young whiteblue bulls; 2 groups were given the control silage ad libitum; one of them (the negative control) received a concentrate of only 6.5% DCP, while the second (positive control) was supplemented with a concentrate of 11% DCP (5% groundnut meal + 5% cottonseed meal + 15% rapeseed meal were added to the concentrate based on grain and dried beet pulp). The third and fourth groups were given the ProSil silage and the Rumipec silage; both of these groups were also given the low protein concentrate (6.5% DCP). Concentrate was offered to each group at 0.75% of liveweight and was adjusted every 4 weeks. Two series of animals were kept in loose houses on straw bedding while the bulls of the third series were individually tied up. Results and discussion
The chemical composition, digestibility (determined with sheep) and the net energy content of the feeds are presented in Table 8. The digestibility of the organic matter and especially of the protein fraction was higher for the treated silages than
361 for the control. Huber and Thomas (1971) and Andrieu and Demarquilly (1974) also noted an increase in digestibility when urea was added to maize silage.
In earlier experiments Boucqué et al. (1974) found no influence of a urea treatment on tha di^astibility of maize silage. The addition of 2.39% or 1.94% Pro-Sil or 0.5% urea to maize at the time of ensiling increased considerably the digestible crude protein content of the silage. In 1974, however, the increase for the Pro-Sil treated silage was lower than in 1973; this is not only due to the lov/er dose (1.94%) but also to the extremely difficult harvest circumstances in the field caused by high rainfall which made a good co-ordination between the chopper and the Pro-Sil tank quite impossible; this situation enhanced NH3 losses during the chopping process. TABLE 8 MEAN DIGESTIBILITY AND FEEDING VALUE OF FEEDS
Year
1973 -74
1974 -75
Feeds
Maize silage 1. Control 2. Pro-Sil (2.4%) 3. Rumipec (+ 1%) Concentrate 1. Negat, contro] 2. Posit, control 3. Pro-Sil 4. Rumipec
Maize silage 1. Control 2. Pro-Sil (1.9%) 3. Rumipec (1%) Concentrate 1. Negat, control 2. Posit, control 3. Pro-Sil 4. Rumipec
Digestion coefficients
Organic matter
69.9 75.0 72.2
--
72.7 75.0 74.4
--
(sheep) Crude Protein
58.2 73.2 75.2
----
58.7 73.2 70.2
_ ---
N-free extract
73.9 77.2 74.6
-· --
76.8 77.2 77.3
. -·--
Dry matter (%)
25.6 26.3 26.3
84.2 85.0 83.7 84.3
26.7 25.4 26.7
85.5 85.2 84.5. 85.2
% of
Digest, crude protein
5.4 9.9 10.4
7.7 12.7 8.7 7.6
5.2 7.9 9.4
7.7 12.8 7.6 7.7
DM
Starch equivalent
62.1 66.8 63.0
75.9 76.8 76.7 77.0
64.7 66.7 65.3
75.2 76.1 76.2 76.0
362 From the results shown in Table 9 it can be concluded that
during the first 140 days of the fattening period, the NH3 and urea treated maize silage gave an increase in feed intake to the same extent as did the positive control, compared with the negative control group, but the effect on daily gain was less for groups receiving NPN than for the plant protein group. During the second part of the trial (from 140 days until the end) however, the daily gain of both NPN groups was significantly higher than for the negative and positive control, owing to a higher net energy intake.
For the entire fattening experiment the addition of both NPN sources in the maize silage or the incorporation of plant protein in the concentrate resulted in a higher protein and net energy intake and a significant increase (P <0.05) of the growth rate compared with the negative control. These results prove that 6% digestible crude protein in the dry matter of the total ration is only sufficient to obtain a daily gain of 1 kg with young bulls. In a review article concerning fattening experiments in France, Fekete (1974) cited an average decrease of 10% of the daily gain when urea was added to maize silage instead of plant protein sources. Essig (1969) , Meiske et al. (1969) , Wilkinson et al. (1973) and many other American authors, obtained satisfactory results with urea treated maize silage for beef cattle. Many reports from Michigan State University demonstrate the good animal performance obtained vith ProSil treated maize silage.
Owing to the highest daily gain, the feed conversion was somewhat better for the ProSil treatment than for the other groups. The increase of the Ν level in 3 out of the 4 rations improved not only the daily gain but also the slaughter results. Taking into account the present price ratios between plant protein sources and the NPN sources, the decrease of the concentrate price (Table 9) could not compensate for the increase in the cost of the silage when NH3 or urea were used instead of plant protein.
TABLE 9 PERFORMANCE OF BULLS FATTENED ON MAIZE SILAGE TREATED WITH NPN (MEAN VALUES OF 2 EXPERIMENTS + SE)
363
Experimental group
Number of bulls (groups) Initial liveweight (kg) Weight at 140 days (kg) Final liveweight (kg) Experimental days Daily liveweight gain (g) - from start to 140 d. - from 140 d. to end - total exper. period Daily feed intake - concentrate - maize silage - dry matter - digest, crude protein - starch equivalent Daily intake(g/kg W0
·75)
1. From' start to 140 d. - dry matter - digest, crude protein - starch equivalent
2.From 140 d. to end - dry matter - digest, crude protein - starch equivalent
3. Total exper. period - dry matter - digest, crude protein - starch equivalent
Feed conversion (kg) - concentrate - maize silage - dry matter - digest, crude protein - starch equivalent Slaughter data (%) - weight loss after 20h fasting
- dressing out Feed cost price (BF) - per kg concentrate - per kg silage (**) - per kg gain
Negative control
21 (3) 287.3 423.5 545.6 257.4
973a*+ 34
1040a + 40
1004a + 32
2.99 18.1 7.29 0.445 4.93
81.7 5.0 55.1
77.5 4.7 52.6
79.1 4.8 53.5
2.98 18.1 7.27 0.444 4.91
2.53a+0.15
62.52a+0.26
6.85 0.65 32.2
Positive control
21 (3) 289.3 449.4 566.7 255.3
1144b + 42 1017
a + 34 1087b + 33
3.12 19.2 7.71 0.604 5.24
84.5 6.5 57.1
78.8 6.3 53.7
81.9 6.4 55.7
2.88 17.7 7.10 0.556 4.82
2.03a+0.14
63.43b+0.28
7.40 0.65 32.8
Pro-Sil
21 (3) 289.9 438.4 578.8 259.7
1061ab+ 38
1173b + 31
1112b + 20
3.11 19.3 7.57 0.630 5.29
82.1 6.9 57.2
78.6 6.5 55.2
79.5 6.6 55.6
2.79 17.4 6.81 0.566 4.76
2.41a+0.12
63.45b+0.23
6.75 0.86 33.8
Rumipec
20 (3) 288.2 431.7 570.8 260.8
1025a + 39
1152b + 38
1084b + 19
3.07 19.3 7.74 0.693 5.30
85.1 7.7 58.0
80.9 7.2 55.7
82.1 7.3 56.2
2.83 17.8 7.15 0.639 4.89
2.44a+0.19
63.69b+0.31
6.75 0.77 32.8
(*) Means on the same line bearing different superscript letters differ significantly at Ρ <0.05 (a, b)
(**) Cost price of Rumipec: 10 BF/kg; Pro-Sil: 8.16 BF/kg
364
CONCLUSION The feeding value of maize silage is generally higher than
that of dehydrated wholecrop maize pellets. Maize silage is a highly palatable feed that enables
economical production of beef. Beef production rations based on maize silage require
supplementation with crude protein in order to obtain high animal performance. NPN sources may be added at ensiling time to supply a portion of the crude protein in rations containing large amounts of maize silage.
ACKNOWLEDGMENT
The authors are indebted to Mr. J. Vanacker (T. ing.), F. Verhaegen and A. Hertegcnne for skilled technical assistance.
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Animal Feed Science and Technology, H\976) 369-379 3 6 9 Elsevier Scientific Publishing Company. Amsterdam - Printed in The Netherlands
ENERGY SUPPLEMENTATION OF MAIZE SILAGE HARVESTED AT DIFFERENT MATURITY STAGES
A. GIARDINI, M. VECCHIETTINI and A. LO BRUNO CNR - Centro di Studio per la Conservazione dei Foraggi, Agronomy Department, University of Bologna, Italy.
ABSTRACT
Trials were carried out in order to define the most convenient harvest stage for maize silage and high moisture grain used in the fattening of young bulls.
The best results were obtained with the riper forage (harvested at 39% DM content) in an all-maize silage ration, i.e. without the addition of concentrates.
Earlier harvests (24% and 28% DM) gave rations with a higher feed efficiency of the DM but were not feasible because of the lower crop yield and the higher feeding costs.
This trend proves that, within the limits of the maturity stages considered in our trials, the crop yield is the most important factor.
The addition of concentrates (1% LW per day) improved the animals' performance (daily gain, dressing %, feed efficiency), but increased the ration's cost and reduced the number of head/ ha which could be fed. On the whole, the effect of concentrates was indirectly correlated with the stage of maturity of the crop, improving the technical results obtained with early and regular maize silage and reducing those obtained with ripe forage.
The comparison between dry maize meal and high moisture grain shows similar technical results for these two forms of supplement.
INTRODUCTION
Our previous investigations on beef cattle fattening (Baldoni et al., 1971; Giardini, 1970; Giardini and Vecchiettini, 1975a and b) with maize silage harvested at different maturity stages and supplemented with 1% LW/day of concentrates, showed the clear superiority of the dough stage (32 - 33% forage DM content). Earlier harvesting (22 - 25% DM) gave a tendency to higher technical
370 results but with a lower net return owing to lower crop yield. Later harvests (40-42% DM) furnished lower daily gains, higher feed intake and more unfavourable feed efficiency (8-10% less compared to the regular maize silage).
Similar results, at least as a trend, are found in the literature (Byers and Ormiston, 1964; Geasler et al., 1967; Geasler and Henderson, 1968; Gordon et al., 1966; Henderson and Greathouse, 1969; Henderson et al., 1971; Hourmant and Fekete, 1970; Huber et al., 1965; ITEB, 1973; Johnson & McClure, 1968; Nelson et al., 1969; Noller et al·., 1962; Owens et al., 1967; Pratt et al., 1964), where the lower nutritive value of the ripe forage is explained both by the greater lignification of the stalk fibre, and by a lack of assimilation of the grain which, when too hard, is easily left undigested by the animal.
Today's availability of harvesting machines which permit a much shorter cutting and a higher shattering percentage of the kernels, re-opens the problem concerning the time of harvesting maize silage with reasonable prospects of improving the results obtained to date with riper forages. Therefore we conducted some further trials on this subject. One was concerning the comparison, in a factorial design, among three stages of maturity of maize silage (24-28-39% DM at harvest) with two energy levels (all silage ration vs. silage + 0.7% LW/day of concentrate as shelled maize grain). Because all the animals received 1 kg/head/ day of 40% protein supplement, the two definitive concentrate rates were 0.3% and 1% LW/day respectively. The second experiment was carried out in order to compare two kernel moisture levels (38 and 34%) and dry meal in a factorial design with two maize silage maturity stages (24 and 28% DM at harvest). The ration was based on silage ad libitum + 1% LW/day of concentrates as dry meal.
The trials were conducted on young Polish Holstein bulls raised in slotted floor housing, from an initial weight of 240 kg to a slaughtering weight of 420-440 kg. The animals were weighed every 15 days and each time the concentrate level of the ration was adjusted to the average body weight recorded for the group.
The maize forage characteristics are given in Table 1. Table 2 shows the chemical composition of the single feed
and of the daily rations together with the costs, calculated
371
TABLE 1 DRY MATTER CONTENT AND PLANT COMPOSITION OF MAIZE FORAGES HARVESTED AT THREE DIFFERENT MATURITY STAGES
Harvest stage
Milk stage Dough stage Late dough stage
DM (%) 24.0 29.4 39.1
Plant composition (% of DM) stalk 33 30 22
leaves 19 18 18
husks 10 8 6
cob 10 9 9
kernels 28 35 45
TABLE 2 CHEMICAL COMPOSITION AND COSTS OF THE FEEDS AND THE RATIONS
Feeds and rations
Early maize silage Regular maize silage Late maize silage High moisture grain High moisture grain Shelled grain (dry meal) Protein supplement 3 Rations Experiment 1 All maize silage:early
regular late
1% LW/day concentrate: early- maize silage
regular maize silage late maize silage
Experiment 2 Early maize silage: dry meal high moisture 66.6% high moisture 62.3% Regular maize silage: dry meal high moisture 66.6% high moisture 62.3%
DM (%)
23.9 28.2 36.9 66.6 62.3 85.5 91.0
26.6 30.8 39.8
33.0 37.8 47.1
33.2 32.4 32.2
37.9 36.3 36.3
Chemical composition (% crude
Prot.
8.7 8.5 8.6 10.4 10.4 9.6 45.8
13.9 13.3 13.1
13.5 13.1 14.0
13.3 13.7 13.7
13.1 13.3 13.4
values in DM) Ether extr. 2.7 2.6 2.3 4.6 4.4 4.3 0.6
2.4 2.4 2.1
2.9 2.8 2.6
2.9 3.0 2.9
2.8 2.9 2.8
Fibre
26.1 23.5 23.1 3.1 2.8 3.1 8.2
23.6 21.6 21.3
17.6 16.4 16.2
17.8 17.7 17.5
16.4 16.7 16.3
N-free extr. 56.7 59.8 60.6 80.4 80.8 81.6 31.5
53.2 56.0 57.1
60.4 62.2 61.9
60.4 60.6 60.3
62.2 61.5 61.9
Ash
5.8 5.6 5.4 1.5 1.6 1.4 13.9
6.9 6.7 6.4
5.6 5.5 5.3
5.6 5.6 5.6
5.5 5.6 5.6
Costs Lit/100" kg DM
9000 1 8000 1 7000 1 15000 1 15O0O 1 15300 1 18000 2
10260 9275 8335
11835 11075 10433
11750 11730 11760
11080 10900 11020
'Opportunity cost' vs. dry shelled maize grain (9.0 t/ha at Lit. calculated on the following parameters:
125 OOO/t)
early maize silage regular maize silage late maize silage high moisture grain
3 Composition:
yield 14.3 t/ha DM and 12.5% storage losses ge : " 15.9
: " 17.7 η : " 7.6 at farm Soyabean meal Colza meal Urea
II II II
Dicalcium phosphate Calcium carbonate Mineral mix Calcium sulphate Vitamins A and D
" " 11 ti π g
Il II o
40% 43% 4% 5% 2% 5% 1%
1300 g/t
0% 0% 5%
372 on the current market price for the feed bought and on the "opportunity cost" for the forages produced on the farm.
Table 3 summarises the technical results of the first trial.
DAILY GAIN
The average daily gains increased with the increase in the ration's concentrate level and proved to be almost independent of the forage's harvest stage. However, an interaction, "type of silage χ energy level" was recorded: the daily gains increased with the delay in date of harvest for the all silage rations, whereas they decreased in the 1% concentrate diets. The addition of concentrates was more effective with the more immature forage, with differences in the daily gains reaching 226, 168 and 37 g, respectively for the early, regular and late harvests.
FEED INTAKE
The feed intake increased with the increase in DH% (r = 0.96**) and with the decrease in the acid content (r = 0.95**) of the ration, either because of the effect of the delay in harvest or else as a consequence of the concentrate supplementation. The highest daily intake increases occurred, however, between the first and second harvest stage, particularly in the allmaizesilage rations.
For each 1% increase in the maize silage DM content, the daily intake of DM increased:
for the all maize silage rations: 135 and 40 g respectively from early to regular harvest maize silage and from regular to late; for the 1% LW/day concentrate rations: 80 and 6 g, in the same order as above.
The lower increases in the late harvested forages, both with and without concentrates, could be explained by greater stalk lignification which increases the work of chewing, thus reducing palatability. The concentrate added also gave different increases in feed intake depending on the maize silage harvest stage: in fact, the increase in daily DM intake was 980, 720 and 430 g respectively for early, regular and late maize silage.
The reduction in the daily maize silage intake is of
TABLE 3 TECHNICAL RESULTS OF THE FIRST EXPERIMENT
^^■^^ Rations
Parameters ^^^
Average daily gain kg Daily feed intake: Maize silage kg Shelled corn kg Protein supplement kg Dry matter kg DM (% LW/day) Roughage: concentrate 2 Dressing % 3
Feed efficiency: Live weight kg DM/kg Carcass weight kg DM/kg
Yield/ha: 4
No. of cattle Live weight kg Carcass weight kg
All Early
U)
0.985
23.4 -
1.0 6.51 1.95
63:37 56.18
6.60 12.37
7.45 2200 1175
maize silage Regular
U)
1.027
22.2 -
1.0 7.15 2.14 56:44 56.65
6.96 12.93
7.56 2330 1250
Late (J)
1.078
17.8 -
1.0 7.49 2.23 48:52 57.18
6.95 12.79
8.16 2640 1430
1% Early
1.211
19.3 2.4 1.0 7.49 2.12 44:56 57.88
6.18 11.24
5.24 1900 1045
ι
concentrate Regular
1.195
17.4 2.4 1.0 7.87 2.30 40:60 58.48
6.60 11.80
5.37 1925 1070
Late
1.115
13.4 ;
2.4 1.0 7.92 2.41 34:66 58.74
7.10 12.72
5.73 1915 1070
Averages All maize silage
1.030
21.1 -
l.O 7.05 2.11 -
56.67
6.84 12.70
7.72 2390 1285
1% cone.
1.174
16.7 2.4 1.0 7.76 2.28 -
58.37
6.61 11.95
5.45 1913 1062
Early
1.098
21.3 1.2 1.0 7.00 2.04 -
57.03.
6.38 11.78
6.35 2050 1110
Regular
1.111
19.8 1.2 1.0 7.51 2.22 -
57.56
6.76 12.36
6.47 2128 1160
Late
1.09'
15.6 1.2 1.0 7.70 2.32 -
57.96
7.02 12.75
6.95 2278 1250
1 Early = 23.9% DM and 28% DM'grain in total 2 Including the grain contained in the maize 4 Considering the average presence to be 3O0
DM; regular = 28.2 and 35.5%; late = 36.9 and 45.0% silage '6 Hot carcass weight - 2%/farm live weight - 5% days/yeer.
374
particular interest: for each kg of concentrate DM fed, the silage DM intake decreased by 430, 650 and 7 90 g, again for early, regular and late maize silage. These quantities correspond to about 2 kg of maize silage for all the cases. This means that within the limits considered in our trials, the daily feed intake is reduced by about 1 kg for each kg of concentrate added.
DRESSING PERCENTAGE
This factor increased with the delay in forage harvesting and with the increase in the ration energy level. It is evident, therefore, how this is directly correlated to the ration's concentrate content (r = 0.98**) independently of the diet's fibre quality, the kernel's degree, of ripeness and physical'state. In our trials, for every 1% more of concentrates in the diet, the dressing percentage increased by 0.105. In other words, in order to obtain a variation of one point on the dressing percentage, the diet's concentrate content will have to be varied by about 10?
FEED EFFICIENCY
The best results were obtained with the early maize silage 1% concentrate ration. Delay in the forage harvesting caused a deterioration in the feed efficiency both with or without concentrate supplementation. Concerning the effects of this last factor, an evident interaction with the forage harvesting stage was recorded: the concentrate addition improved the feed efficiency of earlier forage rations, whereas it did not show any effect with the riper maize silage.
On the whole these results clearly show the negative effect of the delay in harvesting and of concentrate supplementation on the nutritive value of the forage DM. These trends are evident in Table 4 which gives the relative forage nutritive values, with reference to estimated values of 80, 133 and 120 FU/ 100kg DM for regular maize silage without concentrate, dry maize meal and protein supplement respectively.
TABLE 4 RELATIVE FU/100 kg DM OF MAIZE SILAGE
375
All maize silage 1% LW/day concentrate
Early
84 80
Regular
80 72
Late
81 61
In order to give a practical definition of the best harvest stage for maize silage and of the convenience or not of concentrate integration, in Table 5 the economic results forecast in the current market situation for beef in Italy are reported. These results were calculated in reference to a maize crop with a yield of 9.0 t of shelled maize/ha, equal, as recorded in the agronomic and storage trials, to a yield of 12.5, 14.1 and 16.1 t/ha DM of maize silage at feeding, respectively for the early, regular and late harvests.
The 'oest net profits, in absolute terms, per ha of transformed forage crop, are obtained with the late maize silage (about 40% and 60% DM content in the whole plant and grain, respectively) and without concentrates.
The forage from the early harvest, in spite of its higher nutritive value, furnished disappointing economic results owing to either low crop yield or to a limited energy level of the forage itself ( 21.7 FU/100 kg). The concentrate supplementation of this forage improves the economic results remarkably, so much so as to bring them up to values almost equal to those obtainable with the riper fodder. In other words, the 1% concentrate rations tend to level out the economic results of the fattening enterprise making them practically independent of the forage harvest stage, whereas, in the all-maize-silage rations it is more convenient to use riper forages.
Therefore, in a final analysis, from an economic point of view, the optimum harvest stage for maize silage seems to correspond to the vegetative stage with maximum dry matter yield of the crop, without excluding the possibility of a later harvest, obviously taking care to do a more accurate chopping with a shattering of most of the kernels. Research on the utilisation of machines with a reel for harvest at the advanced dough stage, with forage at
TABLE 5 ECONOMIC RESULTS OF THE FIRST EXPERIMENT
"~"~—— ^ Rations
Parameters ~~~~~___
Feed costs: per kg gain of LW Lit per kg gain of carcass Lit Net return per year 1
per head 1000 Lit per ha 1000 Lit
All maize silage early
678 1270
7 52
regular
646 1200
28 212
late
580 1067
63 510
1ΐ concentrate early
732 1330
38 200
regular
729 1313
49 263
late
741 1328
44 252
Averages all
maize silage
635 1179
33 258
1% concen
trate
734 1324
44 238
early regular
705 688 1300 1257
23 39 126 238
late
661 1198
54 381
1 Considering a buying price of 1650 Lit/kg LW, for costs other than for feeding.
TABLE 6 TECHNICAL AND ECONOMIC RESULTS OF THE SECOND EXPERIMENT
a sale price of 2500 Lit/kg of hot carcass 2%, and 250 Lit/head/day
^_^ Rations
Parameters ~"~——
Average daily gain Daily feed intake: maize silage concentrate protein supplement DM
Dressing Feed efficiency
Live weight kg Carcass weight kg
No. of head/ha Feed cost/kg LW gain
kg
kg kg kg kg %
DM/kg DM/kg
no Lit
Early maize silage dry meal
1.173
19.9 2.45 1.00 7.76 58.05
6.62 12. OO 5.06 778
high moist. 67%DM 1.107
18.7 2.99 1.00 7.36 59.31
6.65 11.80 5.33 780
high moist. 62%DM 1.107
18.7 3.28 1.00 7.41 59.06
6.69 11.92 5.28 787
Regular maize dry meal
1.157
17.4 2.45 1.00 7.91 58.65
6.84 12.28 5.47 758
high moist. 67%DM 1.148
17.8 2.99 1.00 7.92 59.82
6.90 12.14 5.48 752
silage high moist. 62%DM 1.153
17.0 3.28 1.00 7.74 59.67
6.71 11.85 5.57 739
Averages early maize silage 1.129
19.1 2.91 1.00 7.51 58.81
• 6.65 11.91 5.22 782
regular maize silage 1.153
17.4 2.91 1.00 7.86 59.38
6.82 12.09 5.51 750
dry meal
1.165
18.7 2.45 1.00 7.84 58.35
6.73 12.14 5.27 768
high moist. 67%DM 1.128
18.3 2.99 1.0O 7.64 59.57
6.78 11.97 5.41 766
high moist. 62%DM 1.130
17.9 3.28 l.OO 7.58 59.37
6.70 11.89 5.43 763
377 more than 40% DM, would be of practical interest, also in view of a desirable prolongation of the harvesting season.
With regard to the different sources of concentrate, dry meal and high-moisture grain with different DM content, the results obtained (Table 6) showed a very slight technical advantage in favour of the high-moisture grain.
CONCLUSIONS
Once again the results obtained in these trials show the great importance of the stage of harvest of maize silage for technical and economic performance in beef cattle raising.
Forage harvested early, on the whole, has higher DM nutritive values but with decidedly unfavourable technical and economic results owing to the lower crop yield a'nd forage energy content.
Concentrate supplementation clearly improves the livestock raising performance of this forage with a tendency towards a levelling of the economic outcome of the livestock enterprise independently of the forage harvest stage.
Highest profits were obtained with the forage harvested in advanced dough stage (38-40% DM) and without concentrate supplementation.
In practice, the most important and decisive element for the choice of the harvest stage seems to be represented by the productive level of the crop. The better quality and higher feed efficiency value of the immature forages does not appear to be sufficient to compensate for the lower DM yields in the earlier harvests.
Obviously if in this stage of the crop's maximum production the forages should prove .to be too dry and the kernels too hard (respectively more than 40% and 60% DM), it would be logical to foresee the need for very short cutting with shattering of the kernels. In our opinion this is one of the most interesting fields for future research in all of the traditional maize environments where the growing season is long enough to reach the advanced dough stage even for the late hybrids.
In the more northern countries, and even in the second crops of the Mediterranean areas, the problem raised is whether to grow early hybrids for harvest at the dough stage or late hybrids
378 for early harvests two solutions v/ith approximately the same yield.
In these conditions, considering the technical results obtained in our experiments, the late hybrid with 1% concentrate rations, represents the most economically convenient solution. Of great interest, especially in these environments, but also in normal growing conditions, is the research concerning higher plant populations, owing to the wellknown positive effect of this factor on the productive level of the crop.
REFERENCES
Baldoni, R., Giardini, A. and Vecchiettini, M. , 1971. Ricoveri, Silomais e "pastoni" nell'allevamento del vitellone. L'Informatore Agrario, 28.
Byers, J.H. and Ormiston, E.E., 1964 Feeding value of mature corn silage. Journal of Dairy Science, 47, 707.
Geasler, M., Henderson, H.E. and Hawkins, D.R., 1967. Effect of stage of maturity and fineness of chop on yield per acre and feeding value of corn silage. Michigan State University, Report AHBC666.
Geasler, M. and Henderson, H.E. 1968. Effect of stage of maturity and fineness of chop on yield per acre and feeding value of corn silage. Michigan State University, Report AHBC676.
Giardini, Α., 1970. Il Silomais nel'alimentazione del vitellone. Alimentazione Animale, 3, 1126.
Giardini, A. and Vecchiettini, Μ., 1975a I cereali foraggere nell'allevamento del bovino da carne. L'Informatore Agrario, 7, 1835318369.
Giardini, A. and Vecchiettini, M., 1975b, The cheapest feed for beef cattle on dry and irrigated land in northern Italy. Communication presented at EEC Seminar on Improving the nutritional efficiency of beef production. Clermont Ferrand, 1417 Oct.
Gordon, C.H., Derbyshire, J.C. and Humphrey, J.L., 1966. The value of mature corn for silage. USDA, ARS, 44, 176.
Henderson, H.E. and Greathouse, T., 1969. Corn silage for feedlot cattle. Michigan State University, Report AHBC42.
Henderson, H.E., Ritchie, H. , Allen, CK. and Cash, E., 1971. Effect of housing systems and corn silage maturity on feedlot performance of Holstein steers. Journal of Animal Science, 33, 1140.
Hourmant, G. and Fekete, J., 1970. Utilisation du maïs fourrage pour la production de jeunes bovins. ITCF, Compte rendu d'essais, no. 6.
379
Huber, J.T. , Graf, G-.C. and Engel, R.W. , 1965. Effect of maturity on nutritive value of corn silage for lactating dairy cows. Journal of Dairy Science, 48, 1121.
Institut Technique de l'Elevage Bovin, Thieux, 1973. Le Mais Fourrage. Johnson, R.R. and McClure, K.E., 1968. Corn plant maturity. IV-Effects on
digestibility of corn silage in sheep. Journal of Animal Science, 27, 535.
Nelson, L.V. , Hildebrand, S.C., Henderson, H.E., Hillman, D., Höglund, CR., Maddex, R.L. and White, R.G., 1969. Corn silage. Production, harvest and storage in Michigan. Michigan State University, Co-operative Extension Service.
Noller, C.H., Warmer, J.E., Rumsey, T.S. and Hill, D.L., 1962. Comparative digestibilities and intake of green corn and corn silages with advancing maturity. Journal of Animal Science, 22, 1135.
Owens, M.J., Jorgensen, N.A., Mohanty, G.P. and Voelker, H.H., 1967. Feeding value of high dry matter corn silage. Journal of Dairy Science, 50, 983.
Pratt, A.D., Conrad, H.R. and Triplett, G.B., 1964. The effect of stage of maturity on dry matter yield and digestibility of corn silage. Dairy Science Department Service, 8, Wooster, Ohio, USA.
Animal Feed Science and Technology. 1(1976) 381392 381 Elsevier Scientific Publishing Company. Amsterdam Printed in The Netherlands
FACTORS INFLUENCING THE COMPOSITION AND NUTRITIVE VALUE OF ENSILED WHOLECROP MAIZE
J. ANDRIEU Institut National de la Recherche Agronomique, Centre de Recherches Zootechnigues et Vétérinaires, Theix 63110 Beaumont, France.
Much work has been carried out in the United States and in Europe on the composition and nutritive value of wholecrop maize silages. This report summarises the results obtained in our laboratory, published in part (Andrieu and Demarquilly, 1974a,b,c; Demarquilly and Andrieu, 1973) , and discusses them in the light of the very exhaustive reviews published on this subject, (see especially: Owen, 1967; Coppock and Stone, 1968; Hillman, 1969) .
Since 1967, we have made 122 whole plant silages from 15 varieties of maize, mainly early or half early (FAO index under 300) commercialised in France for seed production. These crops were harvested between the milk stage (20% dry matter in the plant) and physiological seed maturity ( about 40% dry matter in the plant) with forage harvesters with well adjusted blades (plant fragments 0.5 to 1.5 cm long) and ensiled either in airtight small tower silos of 4 m^ η = 101) or in large trench silos (n = 21). For 67 of the silages, a solid mixture containing 50% urea (with 46% nitrogen) and 50% minerals was added at ensiling at a dose of 10 kg mixture per tonne of freshly cut forage. All the silages were fed alone, ad libitum, to groups of 6 sheep in order to measure their nutritive value.
The results were corrected for the losses of volatile products during heating and for this we used the equations proposed by Dulphy et al. (1975).
INTRINSIC EFFECTS OF CONSERVATION
Silage making causes only slight modifications to proximate chemical composition (Andrieu and Demarquilly, 1974a). It results only in a passive increase in crude protein content (about 4%) and in crude fibre content (about 7%).
The main modifications due to conservation concern principally
382 the carbohydrate fraction of the plant and the nature of the nitrogen components. Based on the soluble sugars, which disappear almost completely, fermentation gives rise to the organic acids, lactic and acetic, and to alcohol (mainly ethanol): the average content of lactic acid, acetic and ethanol is respectively 54.0, 15.2 and 21.2 g/kg of dry matter in the 122 silages we have studied (Table 1). There was little variation between silages in pH, which dropped below 4.2, thus stopping butyric fermentation from developing. While the proportion of soluble nitrogen (as a percentage of total N) sometimes doubled (increasing from 26 to 47% in the case of 35 silages without additive). (Andrieu and Demarquilly, 1974a), the production of ammonia nitrogen remained low (on average 9% of total nitrogen, η = 122). Losses in the form of effluents were low or nonexistent and therefore it is not surprising that reductions in digestibility between the plant in the field and the plant ensiled are negligible or absent (Harris, 1965; Noller et al., 1965; Andrieu and Demarquilly, 1974a).
INFLUENCE OF STAGE OF HARVEST
For a maize which develops normally after flowering, the later the harvest the higher the dry matter content. In relation to this, the crude fibre, ash, and, to some extent, total protein contents diminish, (Coppock and Stone, 1968; Demarquilly and Andrieu, 1973). This change results essentially from development of the grain and thus from transformation of soluble sugars into starch in the grain (Andrieu and Demarquilly, 1974a). The starch is not affected by fermentation, the intensity of which diminishes as the harvest is made at greater maturity (Table 1). With between 20 and 40% dry matter in the whole plant, conservation quality remains satisfactory.
The coefficient of organic matter digestibility of the 122 silages was high (70% on average) and varied between 59.5 and 76%. The average value is comparable with that obtained by American research workers. For a given variety harvested at different stages or for the varieties as a whole, the influence of stage at harvest on the digestibility of green fodder (Demar
quilly, 1969) or silage was low (Andrieu and Demarquilly, 1974a).
TABLE 1 COMPOSITION AND NUTRITIVE VALUE OF MAIZE SILAGE WITH (+) OR WITHOUT (-) ADDITION OF UREA AND MINERALS AT ENSILING (2)
Dry matter content
20 to 25%
25 to 30%
30 to 35%
35 to 40%
40 to 45%
Total
No. of silages
8 (-)
14 (+)
17 (-)
14 (+)
25 (-)
21 (+)
5 (-)
9 (+)
9 (+)
122
Contribution of ears in
DM«1» (%) 40.9
50.0
57.2
53.4
59.7
58.3
63.2
59.7
61.7
56.4
Silage composition (% DM) Crude protein
8.3
15.0
6.9
12.4
8.0
11.9
8.0
11.9
11.4
Crude fibre
23.9
23.3
20.5
21.0
18.4
18.7
16.9
18.9
19.1
20.0
Silaqe characteristics
pH
3.75
4.05
3.75
4.05
3.80
4.05
3.95
4.20
4.25
3.95
NH3-N (% of total N)
6.6
8.3
5.3
14.2
5.5
12.0
5.1
15.4
11.0
9..0
Lactic acid (3)
62.8
62.4
48.4
57.5
48.5
56.4
46.7
55.7
50.0
54.0
Acetic acid (3)
10.8
22.0
15.5
15.4
13.4
14.1
9.3
13.6
11.1
15.2
Butyric acid (3)
0.2
0.4
0.3
l.O
0.2
0.4
0.2
0.6
0.2
0.4
Ethanol (3)
48.6
48.8
27.6
31.9
12.8
8.7
4.7
4.7
3.7
21.2
Organic matter digestibility (%)
68.4Ì1.6
68.4^1.6
69.9-4.2
70.4^2.6
70.3Ï3.4
71.6-2.0
69.0-1.9
70.8^2.7
70.2^1.8
70.1-2.9
(1) Ears = grain + rachis + husks + ear shank (2) A solid mixture containing half urea (46% of nitrogen) and half minerals was incorporated at ensiling at
the rate of 10 kg/tonne of forage maize (3) g/kg of dry matter
384 (Table 1). The slightly lower values mentioned in Table 1 in the case of silages with 20 and 25% dry matter are those with a poor grain content (post-flowering temperatures too low) and late harvest (on average 63 days after normal harvest date). This constancy in digestibility, which has also been observed by many American authors (Coppock and Stone, 1968; Hillman, 1969), is not necessarily true for the net energy value for fattening since the composition of digestible organic matter, notably the starch content, varies considerably with the stage at harvest. However, Chamberlain et al. (1971) found that the stage at harvest did not influence the net energy value for fattening of maize silage. This appears to confirm the fact that, in our trials (Andrieu and Demarquilly, 1974b) , the stage at harvest of maize silages did not influence the composition of sheep rumen liquor. The net energy value for fattening, estimated by Breirem's formula, (Breirem, 1954), was on average 0.75 feed units per kg of dry matter, a value very similar to that calculated by Malterre et al. (1970) from American trials with fattening steers.
INFLUENCE OF VARIETY AND OF ENVIRONMENTAL CONDITIONS
In a given trial, the differences in digestibility due to the varieties are often significant (Andrieu and Demarquilly, 1974a) although of relatively small amplitude (maximum difference : 4.2 units - Table 2). This is probably explainable by the fact that most of the varieties studied were bred for grain production, often from the same ancestors. It would, no doubt, have been true if we had compared varieties of very varying earliness, since the American results are very close to ours, although obtained entirely with much later varieties. In contrast, in the case of extreme botanical types of maize, greater differences have been found, particularly when a normal variety was compared with a dwarf maize (Byers and Ormiston, 1965) or with a male sterile maize (Bratzler et al., 1965; Andrieu and Demarquilly, 1974c). According to Galláis (1976), breeding of maize varieties with low lignin contents should increase the digestibility of maize.
The differences in digestibility due to environmental conditions (place, year, sowing date) are of much greater importance
385
TABLE 2 EFFECT OF PLACE, YEAR, VARIETY AND YIELD OF GRAIN ON ORGANIC MATTER DIGESTIBILITY OF MAIZE SILAGES (1)
Year
1970
1972
1973
Place
MONTOLDRE
CLERMONT
MONTOLDRE
CLERMONT
CHADRAT (Near Clermont)
CHANONAT (Near Clermont)
Variety
INRA 258
DEKALB 204 INRA 258
INRA 310
INRA 258 LG 11 FUNKS G 245 INRA 258 LG 11 FUNKS G 245
INRA 258 LG 11 INRA 230 INRA 240
INRA 258 FUNKS G 245 PAG 21 ADOUR 220
Dry matter content
(%)
34.1
35.9 28.2
28.5
30.9 29.4 28.3 33.8 34.0 32.6
22.2 24.4 23.4 24.5
37.7 38.3 36.7 37.6
Yield of grain
(Tonnes of DM/ha)
4.6
3.5 6.7
6.6
4.5 2.5 4.2 6.7 8.7 6.7
-
5.7 6.0 6.0 6.1 .
Organic matter digestibility (%)
75.0
74.4 75.1
74.2
72.1 68.7 70.2 72.2 70.6 72.1
67.1 68.3 68.4 68.9
70.5 71.5 70.3 67.3
(1) Only silages with urea and minerals
3X6
as the results with the variety INRA 258 indicate (maximum difference 7.9 units Table 2). The trials carried out in our laboratory (Andrieu, 1973; Andrieu and Demarquilly, 1974a), showed that maize grown in poor conditions (drought at flowering, low postflowering temperatures, early frost) and therefore poor in grain, had reduced digestibility compared with normal maize. Thus among silages harvested more than 40 days after flowering, those with less than 55% ear (with husks) in the total dry matter have a digestibility reduced by an average of 3.8 units compared with those containing at least 55% of ear (67.7%, η = 39 versus 71.5%, η = 67). The conservation quality and digestibility are little modified by increases in plant density (Andrieu and Demarquilly, 1974a).
INFLUENCE OF INCORPORATION OF NONPROTEIN NITROGEN DURING SILAGE MAKING
The addition of urea during silage making, especially if it is associated with minerals, as in our trials, increases the buffering capacity of the plant so that the same maize crops, ensiled with or without minerals, differ in their fermentation characteristics (Johnson and McClure, 1968) (Table 3). However, for maize crops grown in good conditions and harvested at 25 to 35% dry matter, the addition of urea is not significant since the greater lactic fermentation which occurs is sufficient to reduce the pH to below 4.2. Butyric fermentation then remains inhibited and ammonia formation remains small (below 10% of the total Ν Table 3) .
Silages containing urea have greater organic matter digestibility than the corresponding control silages fed without urea: 71.6 versus 68.8% in the 24 comparisons we have made. As Table 3 shows, the difference increases when the comparison is made on crops with a low crude protein content. The nitrogen content of silage can thus be a factor limiting growth of microorganisms present in the rumen and responsible for digestion (cf. also Owen, 1967). The critical level is about 8% crude protein in the corrected dry matter (Andrieu and Demarquilly, 1974a).
Ammonia associated with molasses and incorporated in the same dose as urea (on the basis of nitrogen) produces maize silage
TABLE 3 .(D EFFECT OF ADDITION OF UREA AND MINERALS AT ENSILING ON THE COMPOSITION AND NUTRITIVE VALUE OF MAIZE SILAGE
Place
MONTOLDRE (3) 1970
OTHER TRIALS
No. of comparisons
6 without urea
6 with urea
18 without urea
18 with urea
Dry matter content (%)
29.5
29.5
30.6
31.4
Ash (% of DM)
5.4
6.4
5.7
6.5
Crude protein (% of DM)
4.9
10.1
8.3
12.3
Silage characteristics
pH
3.75
4.20
3.85
3.95
NH -N (% of
total N)
5.0
27.5
5.5
8.7
Lactic acid (2)
43.5
58.7
48.3
54.9
Acetic acid (2)
14.3
14.3
13.2
14.1
Butyric acid (2)
0.6
2.5
0.2
0.2
Organic matter digestibility (%)
64.1+3.7
70.3+1.6
70.3+2.2
71.9+2.4
(1) A solid mixture containing half urea (46% nitrogen) and half minerals was incorported at ensiling at the rate of 10 kg/tonne of forage maize.
(2) g/kg of dry matter (3) drought stricken maize
388 with fermentation characteristics and organic matter digestibility very similar to those of silage made with urea, (Demarquilly, unpublished data).
CONCLUSION: Methods of estimating the nutritive value of maize silage
The conservation quality of maize silage harvested at between 20 and 40% dry matter and then conserved without additives is generally very good, at least if the conditions necessary for successful silage making (fine chopping, rapid filling, airtight silo) are met. This is also true of silages made from normally developed maize harvested at between 25 and 35% dry matter with urea added.
The organic matter digestibility of maize silages which depends essentially on that of the corresponding standing crop is, on average 71.5% for normally grown maize crops, but it can vary between quite wide limits (in our study from 67.3 to 76%'when nitrogen was not a limiting factor). It is therefore important, in determining rations, to allow for these variations. There is no significant correlation between the coefficient of digestibility of normally developed maize (fresh or as silage) and the principal criteria of the age of the plant at harvest (dry matter content, crude fibre, percentage of ear, number of days after female flowering (Demarquilly, 1969; Andrieu and Demarquilly, 1974a). However, if only maize crops harvested more than 40 days after female flowering (which make up 95% of our silages) are considered, the correlations become highly significant especially with crude fibre content and percentage of ear, both for all samples and for those with more than 8% crude protein content (Table 4) .
The coefficient of apparent digestibility of crude protein varies between quite wide limits since it depends essentially (r^ 0.95) on the crude protein content of the silage. The latter averages 8% for maize grown in good conditions but it can vary between 5 and 10% according to the date of harvest, fertilisation, environmental conditions etc.
We have not discussed here the mineral and trace element content. It should be noted nevertheless that maize is poor in
TABLE 4 CORRELATION BETWEEN THE COEFFICIENT OF ORGANIC MATTER DIGESTIBILITY OF WHOLE PLANT MAIZE SILAGE AND FIRSTLY THEIR COMPOSITION AND SECONDLY THEIR DATE OF HARVEST (1)
Crude protein % DM (CP) Crude fibre % DM (CF) CP, CF. DM content CP, CF. Days (1) , CP, CF. Ear % (2) DM%, ear% Days, ear% DM%, ear%, CP, CF.
All samples (3)
No. Samp
les (N)
122 tl
Π
II
115
ιι
II
Coeffic
ient of correla
tion (R)
0.032 NS (4)
0.457 HS 0.485 HS
0.500 HS
0.502 HS 0.540 HS 0.547 HS 0.541 HS
0.610 HS
Cays after flowering > 45 (1)
Ν
95 II
II
II
88 'Il
tl
H
R
0.228 NS
0.455 HS 0.456 HS
0.466 HS
0.506 HS 0.594 HS 0.601 HS 0.604 HS
0.628 HS
Days after flowering ]> 45 Crude protein > 8%
Ν
73
70
R
0.148 NS
0.507 HS 0.512 HS
O.513 HS
0.535 HS 0.543 HS 0.545 HS 0.558 HS
0.591 HS
Dry matter content > 27%
Ν
90
84
R
0.239 NS
0.483 HS 0.559 HS
0.586 HS
0.565 HS 0.587 HS 0.594 HS 0.593 HS
0.755 HS
Ì
Dry matter content > 27%
Crude protein >8%
Ν
66
64
R
0.114 NS
0.486 HS 0.521 HS
0.525 HS
0.529 HS 0.566 HS 0.626 HS 0.568 HS
0.688 HS
(1) Harvest date expressed as days after flowering. (2) % of ear (with husks) in harvested dry matter. (3) All samples were harvested at least 38 days after female flowering. (4) F test for the level of significance g of the simple and multiple regressions. HS = Highly Significant (P < 0.001). MS = Non Significant o
TABLE 5 MINERAL COMPOSITION OF MAIZE SILAGE
TRIALS IN FRANCE COPPENET (1972) (Finistère) CROSSET-PERROTIN (1972) Nord-Ouest Centre-Ouest Sud-Ouest Nord-Est Centre-Est MAGNY (1962) Sud-Ouest MORRISON (1950) USA NATIONAL RESEARCH COUNCIL
Macro-elements (g/kg of DM)
Ρ
2.3
2.8 3.0 2.2 3.8 3.0
1.6-2.7
2.2
2.3
Ca
2.2
4.0 3.7 3.6 4.4 4.7
2.0-4.4
3.6
3.3
Mg
1.2
1.5 1.6 1.6 1.8 1.5
1.5-3.6
1.8
2.4
Na
0.23
0.18 0.15 0.26 0.06 0.10
0.3-0.9
0.3
0.3
Κ
11.5
15.2 13.9 13.8 14.9 13.7
9.9-16.4
-
11.5
S
1.1
1.8 1.9 1.6 1.8 1.9
3.7-2.2
1.4
1.1
Trace
Μη
37
58 69 50 51 57
26 - 93
109
50
-elements (mg/kg of DM)
Sn
26
23 22 23 27 24
-
20
Cu
4.7
6.8 5.8 6.9 6.9 6.8
2/3-12.4
4.8
10 . —.
Co
0.03
-
-
-
-
-
0.02-0.11
-
0.09
391
calcium and phosphorus and also various trace elements (particularly Cu,Zn, Mn - Table 5 ) . In addition, Wiseman et al. (1938) have shown that the carotene content of maize plants diminishes rapidly with increase in the proportion of dead laminae in the plant (maturity, frost, etc.).
REFERENCES
Andrieu, J., 1973. Influence du gel à un stade de végétation précoce or de températures basses durant la phase de maturation du gras sur la composition et la valeur alimentaire des ensilages de mais. Bull. Techn. CRZV. Theix - INRA, 12, 45-50
Andrieu, J., 1975. Le maïs gelé fait un ensilage de moindre qualité. Rev l'Elevage, 36, 61.
Andrieu, J. , 1976. Agronc.nic factors affecting the growth and composition of the maize plant. In: J.C. Tayler and J.M. Wilkinson (Editors). The maize crop as a basic feed for beef production. Animal Feed Science and Technology
Andrieu, J, and Demarquilly, C., 1974a. Valeur alimentaire du maïs fourrage II - Influence du stade de végétation, de la variété, du peuplement, de l'enrichissement en épis et de l'addition d'urée sur las digestibilité et l'ingestibilité de l'ensilage de maïs. Ann. Zootech., 23, 1-25. III - Influence de la composition et des caractéristiques fermentaires sur la digestibilité et l'ingestibilité des ensilage de maïs. Ann Zootech. , 23, 27-43.
Andrieu, J. and Demarquilly, C.,1974b. Composition du jus de rumen chez le mouton recevant à volonté du mais fourrage sur pied ou ensilé. Ann Zootech., 23, 301-312.
Andrieu, J. and Demarquilly, C. 1974c. Composition chimique, digestibilité et ingestibilité d'un maïs male-stérile sur pied et après ensilage. Ann. Zootech., 23, 423-434.
Bratzier, J.W., King, T.B. and Thomas, W.I., 1965. Nutritive value of high-sugar corn silage. J. Anim. Sci., 24, 1218 (Abstr.).
Breirem, K., 1954. Die Nettoenergie als grundlage der bewertung der Futtermittel, in : Nehring K., 100 jähre Möckern. Die bewertung der Futterstoffe und andere probleme der Tiernährung. Dtsh. Akad. Landwort. Berlin, t II, 97-108.
Byers, J.H. and Ormiston, E.E., 1965. Feeding value of dwarf corn silage compared with corn and hybrid corn silages. J. Dairy Sci., 48, 203-205.
3<>2
Chamberlain, C.C., Fribourg, H.A., Barth, K.M., Felts, J.H. and Anderson, D.G., 1971. Effect of maturity of corn silage at harvest on the performance of feeder heifers. J. Anim. Sci. 33, 161166.
Coppock, C E . and Stone, J.B., 1968. Corn silage in the ration of dairy cattle: a review. Cornell Miscellaneous Bulletin 89.
Demarquilly, C , 1969. Valeur alimentaire du mais fourrage. I Composition chimique et digestibilité du maïs sur pied. Ann. Zootech., 18, 1732.
Demarquilly, C , Andrieu* J., 1973. Valeur nutritive et utilisation par les bovins de la plante entière de mais verte, ensilée ou déshydratée. Fed. Europ. Zootech., 24ème Réunion, Vienne.
Dulphy, J.P. , Demarquilly, C , Henry, M., 1975. Perte de composés volatils lors de la détermination a l'étuve de la teneur en matière sèche des ensilages. Ann. Zootech., 24, 743756.
Gallais, Α., 1976. Vers la création de variétés de maisfourrage. Rev. l'Elevage, 48, 3741.
Harris, CE., 1965. The digestibility of fodder maize and maize silage. Expl. Agrie, 1, 121123.
Hillman, D., 1969. Supplementing corn silage. J. Dairy Sci, 52, 859870. Johnson, R.R., McClure, K.E., 1968. Corn plant maturity. IV Effects on
digestibility of corn silage in sheep. J. Anim. Sci., 27, 535540. Malterre, C , Lèlong, G., Haurez, Ph., 1970. Utilisation de l'ensilage
de mais pour la production de jeunes bovins. La production de viande par les jeunes bovins. Editions SEI CNRA, Versailles. Etude n° 46, 253279.
Noller, C.H., Burns, J.C. , Hill, D.L., Rhykerd, CL., Rumsey, T.S., 1965. Chemical composition of green and preserved forages and the nutritional implications. Proc. 9th Intern. Grassland Congress. Sao Paulo, 611614.
Owen, F.G., 1967. Factors affecting nutritive value of corn and sorghum silage. J. Dairy Sci., 50, 404416.
Wiseman, H.G., Kane, E.A., Shinn, L.A., Cary, CA. 1938. The carotene content of market hays and corn silage. J. Agrie. Res. 57, 635669.
Animal hïcil Silence and Technology. 1(1976) 393-400 393 l-.lscvh» Scientific Publishing Company, Amsterdam - Printed in The Netherlands
MAIZE GRAIN OR EARS IN CONCENTRATE DIETS FOR YOUNG FATTENING BULLS
S. BACVANSKI Livestock Research Institute, Novi Sad, Yugoslavia.
ABSTRACT
An experiment was conducted to test the effect of partial or total substitution of ground maize grain with ground ear maize in complete mixtures for the fattening of young bulls. Animals of the control group (Group 1) received ground maize as the main ingredient of the concentrate mixture, those of Group II, ground maize and ground ear maize, and animals of Group III, ground ear maize. Increasing crude fibre in the rations by the addition of ground ear maize significantly decreased dry matter digestibility and increased digestibility of crude fibre. Bulls fed on ground maize achieved the highest daily gain which was significantly higher, by 6.62%, than that of the animals given ground ear maize, and by 3.45% compared to the ration based on ground maize and ground ear maize. Feed conversion per kg of live weight gain (LWG) was similar to daily consumption and it was higher in animals fed on the ground ear maize ration, by 16.95%, compared to those fed on ground maize, and by 8.15% compared to the animals fed on the combined ration. Both differences were statistically significant. Conversion of starch equivalent (SE) showed that the only significant difference was that between animals fed on the ground maize mixture and those fed on the ground ear maize mixture. Conversion of protein depended directly on the amount of feed consumed and the differences of 99 and 57 g per kg of LWG, which were significant, could be attributed to higher consumption of the mixtures based on ground ear maize.
INTRODUCTION
The use of complete rations of high energy concentration in young fattening cattle is not in accord with the nature of digestion in ruminants, whose organs are more suited to rations
394 containing a certain amount of roughages. These concentrated rations are therefore supplemented with a roughage component such as lucerne meal or barley, but owing to the ease of technological preparation, ground ear maize is one of the most suitable sources. The aim of these investigations was to find out the effect of partial or total substitution of ground maize with ground ear maize in complete mixtures for the fattening of young bulls, on digestibility, live weight gain and feed conversion.
MATERIALS AND METHODS
For these investigations three groups were formed containing 18 young bulls of the Dutch Friesian breed which were allotted at random to the diets.
The animals received complete mixtures in which ground maize was partly or completely substituted with ground ear maize as shown in Table 1. TABLE 1 COMPLETE MIXTURES AND THEIR CHEMICAL COMPOSITION (%)
Ingredient Ground maize Ground ear maize Dry sugar beet pulp Sunflower oil meal Urea Salt Ground limestone Premix
Chemical composition Dry matter Crude protein Crude fat Crude fibre N-free extractives
T r e a t m e n I
83.5 -5 7 1.5 1 1 1
84.67 14.25 3.92 4.34 62.30
II
35.5 46.0 5 9 1.5 1 1 1
86.22 14.29 3.27 8.09 60.16
t III
-79.5 5 11 1.5 L 1 1
87.13 14.46 2.83 10.86 58.41
395 The animals of Group I were fed on a complete ration based on
ground maize as a source of energy. In treatment II ground maize was partly substituted with ground ear maize, while the animals of Group III were fed on a mixture based on ground ear maize as the energy source. In all three mixtures urea was the basic protein component and sunflower oil meal was included in these mixtures to equalise the level of protein in the diets. The level of energy in these mixtures was unequal and it decreased in relation to the level of substitution of ground maize by ground ear maize. The animals were individually fed ad libitum and water was available from automatic water bowls.
A digestibility trial was carried out using three representative animals of each group weighing about 300 kg. Digestibility coefficients of the individual nutrients were used to obtain conversion of energy and protein. Data for the digestibility of the rations, live weight gains, conversion of feeds and nutrients were processed by analysis of variance as suggested by Snedecor (1965).
RESULTS OF INVESTIGATION AND DISCUSSION
Digestibility of rations Coefficients of digestibility are presented in Table 2.
TABLE 2 COEFFICIENTS OF DIGESTIBILITY (%)
Dry matter Crude Crude Crude
protein fat fibre
N-free extractives
Τ r I
81 79 76 33 88
88 53 47 46 54
e a t m e η t II
76 78 70 47 83
46** 47 36 64 (59***
III
76 78 63 54 82
30** 05 70* 93* 45***
* =(Ρ <0.05) ** = (Ρ<0.01) *** = (Ρ <0.001)
The ration based on ground grain (treatment I) had the highest digestibility coefficients of all nutrients except crude
3% fibre, while they were the lowest in the mixture where ground maize was completely substituted with ground ear maize. Digestibility of dry matter, crude fat and N-free extractives was significantly higher in animals fed on the mixture of grain and ground ear maize than in those given ground ear maize alone. Although the digestibility coefficient of crude protein was the highest in the animals fed on ground maize, differences between treatments were not statistically significant. On the basis of these data it may be supposed that in well balanced mixtures the content of energy affects dry matter digestibility. Other workers (Putnam et al. 1966; White et al. 1971; Bacvanski et al. 1972; Vucetic et al. 1972; Obraõevic et al. 1972) have also shown that dry matter digestibility increases with higher amounts of concentrates in diets for fattening young cattle. Coefficients of crude fat digestibility depended on its content in the ration and the level of fibre, which is in agreement with the results of McCroskey et al. (1961), Richardson et al. (1961) and Bacvanski et al. (1974), who concluded that an increase of crude fibre in the ration decreased the digestibility of crude fat. In crude fibre there was a reverse tendency, i.e. digestibility was increased with higher content of ground ear maize, similar to results obtained by Cobió et al. (1974) and others.
On the basis of these digestibility coefficients it was found that 1 kg of the complete mixture of Group I contained 0.73 SE, Group II 0.69 SE and Group III 0.68 SE. The energy value of the mixture used in Group I was higher by 5.64% and 7.04% compared to those of Groups II and III respectively, while the difference between mixtures II and III was small (1.32%). There was no big difference in digestible crude protein since its content in the mixtures amounted to 11.33%, 11.21% and 11.29% in the three diets respectively. The results obtained show that partial or total substitution of ground maize with ground ear maize decreases digestibility of the complete mixtures and lowers the energy content of feeds. Weights and_ga_ins
Average weights and gains as well as the duration of fattening are presented in Table 3.
Although there was an initial difference in average live weight of animals of 7.11 kg, statistical analysis showed that
397
it was not significant. Thus there was no influence of initial weight on the results of fattening.
TABLE 3 AVERAGE LIVE WEIGHT, TOTAL AND DAILY GAIN(kg)
Number of animals Average Initial weight Average final weight Total gain Number of feeding days Average daily gain
Difference III II
T r e I
18 159.22 454.56 295.34 229.12 1.29
0.08** 0.04
ns
a t m e η t II
18 155.89 444.50 288.61 231.63 1.25
0.04ns
III
18 152.11 443.06 290.95 240.65 1.21
** = (Ρ <0.01) n s = not significant
Animals fed on the mixture containing ground maize (Group I) achieved the highest average daily gain of 1.29 kg which was higher than that of Group II, (ground maize and ground ear maize) by 6.62%, and higher than that of Group III (ground ear maize) by 3.45%. The result obtained comparing Groups I and III is highly statistically significant (P <0.01) and it may be concluded that the sources of energy in the ration had an effect on live weight gains. The study of Zeremski et al. (1972) showed that animals fed on mixtures containing ground maize achieved higher gains in relation to those fed with different ratios of ground maize and ground ear maize by 1.83 and 7.30% respectively. Milosevic et al. (1973) found a non significant increase in gains by a group of young cattle fed on a mixture containing 60% of ground ear maize compared to that consuming a mixture with 56.25% of ground maize. Comparing complete mixtures on the basis of ground maize and ground ear maize, Davis et al. (1963) , Vucetic et al. (1972) and Bacvanski et al. (1974) obtained higher gains using mixtures with ground maize
398 but the differences were not significant.
On the basis of these results it may be concluded that use of ground ear maize in the mixtures decreases the energy value of the ration and average daily gains. If the percentage of ground ear maize is low, about 50%, the gain will depend on the composition of other ingredients and on the energy value of the total ration. Conversion of feeds and nutrients
These data are presented in Table 4. The highest average daily consumption was in animals which received the ration with ground ear maize as the main source of energy. This consumption was higher than that in animals consuming the mixture with ground maize by 9.73%, and in relation to the combined ration (Group II) it was higher by 4.8%. Increased consumption of rations containing ground ear maize is probably a result of preference given to rations with ear maize due to the roughage present in it. Feed conversion per kg of live weight gain was higher in Group III in relation to Groups I and II by 16.95 and 8.15% respectively. The difference between Groups III and I of 892 g was highly significant (P <_0.001) while the differences between Groups I and II (428 g) and between Groups II and III (464 g) were also significant (P <0.05). Davis et al. (1963), Williams et al. (1968) , Vuãetic et al. (1972) , Bacvanski et al. (1974) and others showed that substitution of ground maize with ground ear maize increases consumption and conversion of feed, which is in agreement with the results of this experiment. TABLE 4 DAILY CONSUMPTION OF FEEDS AND NUTRIENTS ( kg)
Concentrate mixture Per kg of LWG
Starch equivalent Per kg of LWG
Digestible crude protein Per kg of LWG
Dry matter Per 100 kg of live weight
Ration concentration (%)
T r e a t m e n I
6.79 5.26** 4.95 3.84 0.77 0.60 5.77 1.88
86.19
II 7.09 5.69** 4.90 3.93 0.79 0.64* 6.11 2.07 80.10
t III 7.44 6.16*** 5.07 4.20* 0.84 0.69*** 6.48 2.18 78.23
* = (P <0.05) (P <0.01 *** = (P <0.001)
399 Differences in conversion of starch equivalent were not so
prominent since they appeared between animals fed on ground maize and ground ear maize (P <0.05), amounting to 9.21% in favour of the ground ear maize diet. Animals of Group III consumed 6.74% more SE per kg of LWG compared to those of Group II, while the difference between Groups II and I amounted to only 2.3%. Conversion of protein depended directly on the amount of feed consumed, because all mixtures were isonitrogenous. Animals fed on the diet based on ground ear maize consumed 16.61% more protein per kg of LWG than those which received the diet based on the ground maize, and 8.93% more protein compared to the animals consuming the mixed diet. (Group II). Both of these differences were statistically significant (Table 4). Dry matter consumption per 100 kg of live weight showed a tendency to decrease with higher ration concentration, which means that fattening cattle consume less dry matter per 100 g of live weight if the ration concentration is higher.
REFERENCES
Bacvanski, S., Cobié, T., Vucetic", Sof ija, 1972. Maize, corn and cob meal and dry sugar beet pulp as the energy sources in the whole concentrate rations for fattening of bulls. Review of Research Work, 5, Livestock Research Institute, Novi Sad.
BaSvanski, S., Vucetid,Sofija, dobic, T. 1974. Corn and cob meal in complete mixtures for fattening of cattle. Journal for Scientific Agricultural Research, XXVII, No.98, Belgrade.
Cobic", T., Bacvanski, S., Vucetic", Sof i ja, 1974. Evaluation of ground maize and cob meal as a source of energy in fattening young cattle using isonitrogenous rations. Contemporary Agriculture, XXII, 11-12, Novi Sad.
Davis, R.E., Oltjen, R.R., Bond, James, 1963. High concentrate studies with beef cattle. Journal of Animal Science, 22, 640.
McCroskey, J.E., Pope, L.S., Stephens, D.F. and Weiler, G. 196]. Effect of pelleting steer fattening rations of different concentrate to roughage ratios. Journal of Animal Science, 20, 42.
Miloäevi<5, M. , Bacvanski, S. , Coble, T., Vucetic", Sofija and Vlcek, B. 1973. Preservation of high moisture corn by propionic acid and its value in feeding of beef cattle. Science in Practice, 3, 2, Belgrade.
400
Obraíevic C , Bacvanski, S., Cobió, T. and Vuòetió, Sof ija, 1972. Feed conversion with varying ratios of concentrates to alfalfa meal in fattening young bulls. Journal for Scientific Agricultural Research XXV, No.92, Belgrade.
Putnam, P.A., Elam, C.J., Davis, R.E. and Wiltbank, J.N. 1966. Dietary energy and protein effects on rumen volatile acids and ration digestibility by beef heifers. Journal of Animal Science, 25, 988.
Richardson, D., Smith, E.F., Baker, F.H. and Cox, R.F. 1961. Effects of roughage-concentrate ratio in cattle fattening rations on grains feed efficiency, digestion and carcass. Journal of Animal Science, 20, 316.
Snedecor, W.G. 1965 Statistical Methods, Ames, Iowa. Vucetic. Sofi ja, Bacvanski, S. and Cobic T. 1972. Effect of level and source
of energy in fattening of young bulls fed with rations containing urea. Review of Research Work, 6, Livestock Research Institute, Novi Sad.
White, T.W., Reynolds, W.L. and Hembry, F.G. 1971. Digestibility of finishing rations containing various sources and levels of roughage by steers. Journal of Animal Science, 32, 544.
Williams, D.B., Bradley, N.W., Little, CO. and Crowe, W.M. 1968. Effects of oyster shell with and without roughage in beef finishing rations. Journal of Animal Science, 27, 299.
Zeremski, D. , Koljajici, V. and Ilia V. 1972. Effect of replacing ground corn by corn and cob meal and sunflower oil meal by urea on the results of fattening young bulls entirely with concentrates. Journal for Scientific Agricultural Research, XXV, 92, Belgrade.
Animal Feed Science and Technology. 1 (1976) 401-415 401 IINevier Sdentila· Publishing Company. Amsterdam - Printed in The Netherlands
RATE OF GROWTH, FEED UTILISATION AND DIGESTIBILITY OBSERVED WITH DIETS CONTAINING ENSILED MAIZE GRAIN OR MAIZE EARS FED ALONE OR IN MIXTURES
D. LANARI and M. RIONI Istituto di Zootecnica, università di Padova, Italy
ABSTRACT
Rate of gain of beef cattle fed ensiled high moisture maize ears or grain in high concentrate diets gave values comparable to those observed with dry products while feed conversion was improved by the introduction of ensiled products.
Digestibility was higher with ensiled products than with corresponding dry concentrates especially when maize ears have been considered. Dry matter content at harvesting was shown to be important in affecting digestibility since, from the experiments discussed, it does not seem advisable to ensile products with more than 70% dry matter.
Animal performance with mixed diets was affected by the level of maize silage in the diet. The best results were achieved when maize silage comprised up to 55% of the diet dry matter.
Experiments on voluntary intake of mixed diets have shown that the highest dry matter intake is reached when maize silage represents roughly 50% of the total ration dry matter.
Nutrient digestibility of mixed diets of corn silage and concentrates increases as concentrate level increases.
INTRODUCTION
During recent years, the use of ensiled high moisture maize grain or ears has become more and more common in beef cattle feeding. The growing cost of drying and the complete mechanisation of most of the harvesting and ensiling processes are the most probable causes of this trend. Nevertheless, several points need further clarification; they include not only the choice of the best moment for harvesting in order to produce the highest utilisation of nutrients, but also the study of the use of these feeds
402
alone or in combination with dry or ensiled forages in rations for beef production. In this paper we will present and discuss some of the more recent results on these topics.
UTILISATION OF ENSILED MAIZE GRAIN AND MAIZE EARS, IN HIGH CONCENTRATE RATIONS FOR BEEF CATTLE
The literature on this topic does not appear particularly rich. Some of the more significant experiments conducted by different authors using ensiled maize grain or ears in high concentrate rations are reported in Tables land 2. Most of the data have been collected from fattening trials on bulls and only in one experiment (Forsyth et al., 1972) were steers utilised.
If we consider data from trials where dry or ensiled ears have been compared, no difference among treatments can be noted in growth rate. On the contrary, dry matter intake shows a reduction with ensiled ears, so that feed conversion appears significantly improved in comparison with dry ears. Klostermann et al. (1960) obtained comparable results, more than ten years ago, feeding similar rations to steers.
The positive effect on feed utilisation, observed as a result of ensiling high moisture maize ears, has been noted by Forsyth et al. (1972) and Tonroy et al. (1974) also with high moisture, acid-treated grain in comparison with dry corn grain.
Moreover, Tonroy et al. (1974) observed that reconstituting and ensiling dry corn does not allow the same improvements to be made in feed conversion which are observed with corn harvested at a high moisture content and ensiled.
A particular comment has to be made on the data of the second experiment summarised in Table 2. The values reported show that steaming and rolling maize grain is of great advantage for supporting a high growth rate, producing a very low feed conversion ratio. At the same time, no significant difference resulted between ensiled maize grain and ensiled ears, suggesting that ensiled ears have a nutritive value not far from that of grain.
Since the experiments reported appear sufficiently similar in many parameters such as initial and final live weight, daily gains and ration composition, it is possible to make some useful comparisons among them.
TABLE 1 DAILY GAINS, VOLUNTARY INTAKE AND FEED UTILISATION OBSERVED WITH MAIZE EARS DRY OR ENSILED
Number of animals Initial live weight Final live weight Daily gain
Daily dry matter intake Forage Protein supplement Maize
Total daily DM intake Dry matter intake/gain
kg fl
II
II
II
II
II
II
Maize ears dry (Rioni and
16 250.8 435.6 1.36
0.88+
0.43 6.65 7.96 5.85«
Maize ears ensiled
Chiericato, 1972)
16 251.4 435.4 1.35
0.88+
0.45 6.30 7.63 5.65fc
Maize ears dry
(Giardini and
20 231.5 411.5 1.35
0.35++ 0.90 6.51 7.76 5.76a
Maize ears ensiled
Vecchiettini, 1975)
20 230.0 421.0 1.40
0.43++
0.90 5.92 7.25 5.16*
Means within the same row with different superscripts are significantly different (P<0.05) + = hay ++= maize silage, milk stage
TABLE 2 DAILY GAINS, VOLUNTARY INTAKE AND FEED UTILISATION OBSERVED WITH MAIZE GRAIN, DRY, STEAMED AND ROLLED OR ENSILED
Number of animals Initial live weight kg Final live weight " Daily gain "
Daily dry matter intake Forage " Protein supplement " Maize "
Total daily DM intake " Dry matter intake/gain "
Maize grain dry
(Forsyth
6 244 431
1.33
0.75+
0.75 5.98 7.48'^' 5.62
fc
Maize grain ensiled et a ] . , 1972)
6 271 475
1.46
0.78+
0.78 6.22 7.78^ 5.33<
îl
Maize grain ac. treated
6 251 448
1.41
0.72+
0.72 5.80 7.24
a¿
5.13ai
Maize grain steamrolled
Maize grain ensiled
(Bonsembiante et al..
20 258.6 435.8
1.49'
0.96++
0.86 5.69 7.52 5.04
a
20 259.2 423.3
1. 3βαί
0.96++
0.86 5.73 7.55 S.47ab
Maize ears ensiled
1974)
20 259.4 418.8
1.34a
0.96++
0.86 6.22 8.04 6.00^
Means within the same row with different superscripts are significantly different (Ρ (0.05) + = ground hay mixed with concentrates ++= hay
405 From the results, two conclusions can be made: first,
ensiled maize grain or ensiled ears in high concentrate rations support a growth rate similar to that observed with dry products. Second, the use of ensiled highmoisture ears or grain allows a certain improvement in feed utilisation. This advantage was noted also in research on dairy cows, (Zogg et al., 1961; McCaffree and Merrill, 1968).
Now, if we consider experiments where digestion trials have been performed we can find some explanation of these results. Klostermann et al. (1960), McCaffree and Merrill (1968) and Bonsembiante et al. (1974), working on corn ears noted that digestibility was higher in ensiled ears than in the dry product. This can be explained by the reduction in cob digestibility that takes place with advancing maturity, as was shown by Thornton et al. (1969). Not so clear is the relationship between digestibility and feed utilisation with ensiled maize grain, since some authors (Polzin et al., 1972; Clark et al., 1973) did not note an improvement in utilisation of highmoisture corn in comparison to dry corn. On the other hand, in many other experiments (McCaffree and Merrill, 1968; Clark and Harshbarger, 1972; McKnight et al., 1973; Tonroy et al., 1974) some improvement in the digestibility of ensiled grain was observed.
TABLE 3 EFFECT OF DRY MATTER CONTENT ON MAIZE GRAIN DIGESTIBILITY
Dry matter content (%)
Digestion coefficients (%) Dry matter Organic matter Crude protein Energy
Ensiled grain
75
77. Ob
78. lb
67.3afc
75.0*
Propionic and acetic acid treated grain
75
77.4fc
78.5* 67.3
tó
■75.3*
Propionic acid treated grain
75
77. lh
78.9b
68. Sb
75.9b
Dry grain
89
74.2a
75.4a
64.1a
72.4a
Means within the same row with different superscripts are significantly different (P <0.05) . Reference: McKnight et al. (1973).
406
In Table 3 are given the results reported by McKnight et al. (1973), where the superiority of grain harvested at highmoisture content and ensiled or acid treated, in comparison with dry grain, appears clearly. According to this author, the higher digestibility of grain harvested at high moisture content, to whatever treatment it was subjected, could be at least partially explained by its slower rate of passage through the rumen. From the literature examined, we can draw the conclusion that ensiled ears are better ulitised than dry ears and that there is a similar trend also for ensiled grain. Now we can consider whether there is a moisture level at harvesting which represents the optimum for feed utilisation. In Table 4 are reported data of a trial that we have recently carried out in Padua and whose results have not yet been published. We have been led to conduct this research from an examination of the different performance obtained with beef bulls by Rioni and Chiericato (1971) and by Bonsembiante et al. (1974) with ensiled maize ears of different moisture content.
Maize ears and grain, used in the digestion trial, came from the same field and cultivar; the ears were hand picked and the grain was harvested with a combine.
Both products were ground through a hammer mill and then ensiled in plastic silos of roughly two tons capacity. The digestion trial was performed on bulls according to a 4 χ 4 Latin square design.
As can be seen from Table 4, an increase of 10 points in dry matter content of maize ears produced a significant (P<0.05) reduction of roughly five points in nutrient digestibility.
A similar reduction was observed with maize grain, but the difference reached statistical significance only for energy. Digestion coefficients observed in ensiled grain were significantly higher than in ensiled ears.
From the results of our experiments, it appears of great importance to check dry matter content of both maize ears and grain before harvesting for ensiling. DM level should not be higher than 70% in order to maximise feed utilisation for beef production. When this level is exceeded and at a level close to 80%, digestibility decreases and little fermentation can occur during storage in silos.
407 TABLE 4 EFFECT OF DRY MATTER CONTENT AT HARVESTING ON THE DIGESTIBILITY OF ENSILED MAIZE GRAIN AND MAIZE EARS
Dry matter content (%)
Digestion coefficients (%) Dry matter Organic matter Crude protein NFE Energy
Maize ears ensiled
68
7 5 . 9A*
7 7 . 0 ^ 56.4
a
ABb 83.7 ΠΑ AAb
74.4
79
70.6A a
12.0Aa
51.6a
78 y α
69 y α
Maize ens i
70
87.6B e
88.5ß C
72.2 91.8
C C
86.5ß d
grain led 79
83.6** 85.0
B C
62.3b
89.0S C C
82.4B C
Means within the same row with different superscripts are significantly different (αb Ρ <0.05) {ΑB Ρ <p.01) . Reference: Rioni and Lanari (1976). UTILISATION OF MAIZE GRAIN AND ΓΆΙΖΕ EARS IN ΠΧΕΌ DIETS WITH WHOLECROPΓΆΙΖΕ SILAGE
In Table 5, the results of some trials performed in Italy on fattening bulls with diets containing different ratios of maize silage and concentrates are summarised. In the first experiment (Giardini, 1970), three diets with increasing proportions of the "forage were compared.
Daily gain decreased significantly (P<.0.05) from 1.46 kg to 1.24 kg when percent of dry matter from concentrate was reduced from 90 to 70%. Total dry matter intake increased but feed utilisation worsened with increasing forage content and, because of the low quality of the forage used (maize stover and maize silage at the milk stage), no reduction was noted in the amount of dry matter from concentrate consumed per kg gain. In this case, forage utilisation was very limited and no advantage was derived from its introduction in the diet.
In the second experiment, steamed and rolled maize grain was fed ad libitum in the first treatment, while in the second the ration contained 1/3 maize grain steamed and rolled and 2/3 maize silage.
Finally, in the last treatment, animals were fed only maize silage to 350 kg live weight. Thereafter the silage was reduced
TABLE 5 DAILY GAINS, VOLUNTARY INTAKE AND FEED UTILISATION OBSERVED WITH YOUNG BULLS FED DIETS WITH DIFFERENT RATIOS OF MAIZE SILAGE AND CONCENTRATES.
Diet dry matter Maize silage (%) composition Concentrate (%)
Number of animals Initial live weight kg Final live weight " Daily gain " Daily dry matter intake
Forage " Protein supplement " Concentrate "
Total dry matter intake " Dry matter intake (kg)/kg gain Concentrate dry matter (kg)/kg gain
10 90
20 80
30 70
(Giardini, A., 1970)
48 250.0 400.9 1.41
a
0.81
7.30+
8.11 5.76
a
5.21
48 250.0 400.1 1.34
fo
1.77
7.08+
8.85 6.61« 5.28
48 250.0 401.2 1.20^
2.73
6.36+
9.09 7.57'
c
5.30
0 100
45 55
Bonsembiante et a
12 244.9 417.6
1.23W'
0.76 5.15" 5.91a 4.82^ 4.82
12 248.3 418.8 1.19
ft'
3.37 0.94 3.04" 7.35« 6.18« 3.34
571
43 1.(1970)
12 249.7 420.5 0.98^
3.93 1.09 1.76" 6.78 ' 6.92
C
2.90
63 37
Giardini Vecchiett
20 231.5 424.0 1.33
4.92 O.90 1.93" 7.75 5.82 2.12
65 35
and ini, 1975)
20 228.0 4 30.0 1.33
4.66 0.90 1.63" 7.19 5.42 1.90
Means within the same row with different superscripts are significantly different {ab P<0.05) (.AH Ρ <0.01) + , .·
, = see text I Average data from two periods first 250350 kg live weight animals were fed corn silage and protein
supplement; second from 350 kg to slaughter animals were fed grain silage.
409
to 6 kg per day and maize grain, steamed and rolled, was given in increasing amounts.
Daily gains were reduced with the introduction of maize silage, but the decrease was not so great if we consider the.treatment where the mixed diet was employed. Dry matter intake increased with the presence of maize silage, reaching the highest value with the mixed ration where roughly half of the dry matter was derived from concentrates.
Feed conversion worsened with increasing silage intake but it is important to underline that, at the same time, concentrate intake per unit of gain decreased from 4.8 kg to 2.9 kg.
In the last trial reported, maize silage represented over 60% of the diet dry matter; as an energy supplement, dry maize grain or ensiled highmoisture grain were used. Daily gains were the same with both diets, but dry matter intake was slightly reduced with ensiled maize. Concentrate consumption per kg gain was very low with both diets.
From an overall impression of these trials, forage quality seems to play an important part if a reduction in concentrate use is sought. Moreover, forage has to represent more than 30% of the diet dry matter in order to get good forage utilisation. Finally, it does not appear convenient to divide fattening periods into subperiods with striking differences in ration composition when the rearing period is rather short (150 180 days).
Since it was observed that, with mixed diets, dry matter intake and animal performance can vary greatly, depending on forage quality and concentrate : forage ratio, an intake and digestion trial was performed in Padua using five mixed diets obtained from maize silage and ensiled maize ears given in different ratios and supplemented with protein, vitamins and mineral salts. For this trial, young bulls were used in a 5 χ 5 Latin square design.
The results of the intake experiment are represented in Fig. 1, while the corresponding data are reported in Table 6. The parabolic trend of the curve shows that the highest intake was obtained with the diet where half the dry matter came from maize silage and half from ensiled maize ears. Digestible energy intake too was higher with this diet. The intake observed with the 100% maize ear silage ration, was significantly (P< 0.05) lower than with all other treatments. A study of the diet
410
2.3
2.2σι
ã ì> 2.1
σι i¿ 2.0 o o
1.9
Û 1.8 σι
0 100
25 75
50 50
75 100 % maize ears silage 25 0 % maize silage
Diet dry mat t e r composi t ion Figure 1 DRY MATTER INTAKE OF YOUNG BULLS FED MIXED DIETS OF MAIZE SILAGE
AND MAIZE EAR SILAGE y = 2.1154 + 0.0068x O.000097x2 SDres. = 0.1743 where χ = % DM from ear silage
80 >. ■t: 7 0
Q
w 60 ω 03
D 5 0
■*/
S 40 ί _
ra & 3 0 ro
# 20
• O
Π
■
o 100
25 75
50 50
Diet dry matter composition
75 100 % maize ear silage 25 0 % maize silage
Figure 2 EFFECT OF INCREASING LEVELS OF MAIZE EAR SILAGE ON NUTRIENT DIGESTIBILITY
organic matter O energy G crude fibre crude protein
411
characteristics which could explain the observed trend in intake, has included consideration of % dry matter, % lactic acid, % acetic acid, energy concentration in digestible energy (DE) , pH and % DE of the ration.
The statistical calculations made between daily dry matter consumption and the above listed variables have shown that feed intake appears to be particularly conditioned by digestible energy content of the diet and by the metabolic live weight as reported by Baumgardt (1970). Such phenomena can be expressed by the following equation:
y =219.76 + 146.76x 23.68x2 + 0.0162z Residual SE = 0.711 where y = Daily dry matter intake, kg,
χ = DE,Kcal/g DM, ζ = LW, kg ° ·
7 5
Such a result does not seem easy to interpret. Probably in the diets in which the proportion of the ensiled maize represented more than 50% of the total dry matter, the prevailing elements in feed intake regulation seem to be connected to diet volume and to the longer time of retention of silage residues in the digestive tract, as was observed by Campling (1966) working on hay and silages.
When the proportion of dry matter from ensiled maize ears was higher than 50%, the decrease in consumption of dry matter and of digestible energy, can be explained by a low rumen pH and high VFA concentration (Baumgardt, 1970). Moreover an effect due to diet palatability cannot be excluded.
Considering the digestibility of mixed diets (Table 6 ) , the data indicate a progressive and linear rise in digestibility of organic matter and of energy as the proportion of ensiled maize ears in the diet increased. Digestibility of protein too, although showing a less regular trend than the other components, rose with an increase in the proportion of maize ears in the diet (Fig. 2).
Crude fibre digestibility had an opposite trend since it decreased with increasing content of maize ears in the diet. This
TABLE 6 DRY MATTER CONSUMPTION AND APPARENT DIGESTIBILITY OF MAIZE SILAGE AND MAIZE EARS SILAGE MIXED DIETS (Lanari, 1976)
Diet dry ) Maize ear silage (1) matter ) composition ) Maize silage (.%)
Voluntary intake DM/lOO kg live weight (kg)
Digestion coefficients (î,) Organic matter Crude protein Crude fibre Energy
0
100
2ΛΑΑΒΟ
69.2'?t·'
48.5¿'B
58.9^ 66.3
6*ΰ
25
75
2.164''*
72 3 C'RC
5 1 . 2 ^ 54 . l1^'' 69. 2ÍJC'IÍ
50
50
2.25;Γ*
74.0^* 48.ΦΒ
ΛΑ.\',ΑΒ
ΊΟ.Φ AB
75
25
2.09'lßi'
74.6M S
si.d'B
31.3r"ß
71.6^ö
loo 0
l.82'1a
78.9a/!
62.3^ 16. 9 ^ 76.6
a71
Means within the same row with different superscripts are significantly different (ah Ρ 0.05) (/IΛ Ρ <0.01)
413
phenomenon, already pointed out by other authors in relation to high concentrate diets (Bonsembiante et al., 1969) can be explained in terms of rumen liquor characteristics which are not favourable to cellulolytic bacteria.
The linear trend of the diets studied seems to exclude interaction effects between the two principal dietary components.
Similar conclusions have been reached by Preston (1975) with diets similar to the ones we used and by Kroman et al., (1975) with diets of alfalfa hay and dry maize grain.
From the results discussed in this paper, it can be concluded that ensiling high moisture maize ears or grain is an advantageous technique; it allows us to eliminate the cost of drying, producing a concentrate which is used by fattening animals more efficiently than the corresponding dry products with no influence on daily gains. This can be at least explained by a better digestibility of these high moisture products. Moreover, moisture level at harvesting plays a well defined and important role since it does not seem advisable to harvest ears or grain for ensiling with a moisture level lower than 30 - 33%.
From the experiments on mixed diets where maize silage is the forage component, it appears that the best results in terms of animal performance, feed intake and digestible energy intake, are achieved when roughly 45 - 55% of the dietary dry matter comprises maize silage and the remaining part is from concentrates.
REFERENCES
Baumgardt, B.R., 1970. Control of feed intake in the regulation of energy balance. Physiology of digestion and metabolism in the ruminant. Ed. A.T. Phillipson. Oriel Press, Newcastle upon Tyne.
Bonsembiante, M., Rioni, M., Chiericato. G.M., 1970. Contributo sperimentale sulla produzione del vitellone in rapporto alla dieta, al sistema di stabulazione ed al tipo ristallo. Alimentazione Animale, XIV, 5, 33.
Bonsembiante, M., Rioni, M., Lanari, D., 1969. L'effetto della vaporizzazione e rullatura del mais e della presenza di fieno e di insilato sulle caratteristiche del liquido di rumine e sulle "performances" del vitellone. Alimentazione Animale, XIII, 5, 351.
Bonsembiante, M., Rioni, M., Parigi-Bini, R., Chiericato, G.M., 1974. Ricerche sui pastoni di mais nella produzione del vitellone. Rivista di Zootecnia e Veterinaria, 2, 97.
414
Campling, R.C., 1966. The intake of hay and silage by cows. Journal of the British Grassland Society, 21, 41.
Clark, J.H., Frobish, R.A., Harshbarger, K.E., Derrig, R.G., 1973. Feeding value of dry corn, ensiled high moisture corn and propionic acid treated high moisture corn fed with hay or haylage for lactating dairy cows. Journal of Dairy Science, 56, 1531.
Clark,J.H.,Harshbarger, K.E., 1972. High moisture corn versus dry corn in combination with either corn silage or hay for lactating cows. Journal of Dairy Science, 55, 1474.
Forsyth, J.G., Mowat, D.N., Stone, J.B., 1972. Feeding value for beef and dairy cattle of high moisture corn preserved with propionic acid. Canadian Journal of Animal Science, 52, 73.
Giardini, Α., 1970. Stabulazione e livelli alimentari nell'allevamento del vitellone. Alimentazione Animale, XIV, 3, 11.
Giardini, Α., Vecchiettini, M., 1975. I cereali foraggeri nell'allevamento del bovino da carne. Informatore Agrario, XXXI, 18353.
Klostermann, E.W., Johnson, R.R., Scott, H.W., Moxon, A.L., Van Stavern, J., 1960. Whole plant and ground ear corn silages, their acid content, feeding value and digestibility. Journal of Animal Science, 19, 522.
Kroman, R.P., Clemens, E.T., Ray, E.E., 1975. Digestible, metabolisable and net energy value of corn grain and dehydrated alfalfa in sheep. Journal of Animal Science, 41, 1752.
Lanari, D., 1976. L'effetto di diete contenenti rapporti diversi di mais ceroso e pastone di pannocchia sulla digeribilità delle sostanze nutritive e sulla ingestione volontaria di alimenti. In course of publication.
McCaffree, J.D., Merrill, W.G., 1968. High moisture corn for dairy cows in early lactation. Journal of Dairy Science, 51, 553
McKnight, D.R., Macleod, G.K., BuchananSmith, J.G., Mowat, D.M., 1973. Utilisation of ensiled or acid treated high moisture shelled corn by cattle. Canadian Journal of Animal Science, 53, 491
Polzin, H.W., Otterby, D.E., Murphy, J.M., Johnson, D.G., 1972. Utilisation of ensiled, acidtreated and dry corn by lambs. Journal of Animal Science, 35, 1133 (Abst.)
Preston, R.L., 1975. Net energy evaluation of cattle finishing rations containing varying proportions of corn grain and corn silage. Journal of Animal Science, 41, 622.
Rioni Volpato M., Chiericato, G.M., 1972. Impiego del "pastone di pannocchia" della pannocchia secca di mais e del fieno di erba medica e di loietto nella produzione del vitellone. Alimentazione Animale, XVI, 2, 25.
415
Rioni, M., Lanari, D-, 1976. Perdite di insilamento e digeribilità di pastoni di granella e di pannocchia raccolti a differente contenuto di umidità. In course of publication.
Thornton, J.H., Goodrich, R.D., Meiske, J.C., 1969. Corn maturity. III. Composition, digestibility of nutrients and energy value of corn cobs and ear corn of four maturities. Journal of Animal Science, 29, 987.
Tonroy, B.R., Perry, T.W., Beeson, W.M., 1974. Dry, ensiled high-moisture-ensiled reconstituted high moisture and volatile fatty acid treated high moisture corn for growing-finishing beef cattle. Journal of Animal Science, 39, 931.
Zogg, C.A., Brown, R.E., Harshbarger, K.E., Kendall, K.A., 1961. Nutritive value of high moisture corn when fed with various silages to lactating dairy cows. Journal of Dairy Science, 44, 483.
Animal Feed Science and Technology. 1 (1976) 417-427 4 1 7 Ulsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
UTILISING THE MAIZE CROP IN VARIOUS FORMS FOR BEEF PRODUCTION
C. MALTERRE Institut National de la Recherche Agronomique, Centre de Recherches Zootechniques et Vétérinaires Theix, 63110 Beaumont, France. and C. LELONG Institut Technique des Céréales et des Fourrages, Station Expérimentale de Boigneville, 91720 Maisse, France.
ABSTRACT
Whole crop maize silage is well suited to the fattening of bulls when supplemented with concentrates (850 - 950 g total crude protein per day for dairy breed bulls between 270 and 650 kg), minerals and vitamins.
Supplements of hay are not essential but 1 kg good lucerne or grass hay could slightly improve growth rate. Urea can supply all the nitrogen supplement for animals over 200 kg: in this case, animal performance decreases (by 9 - 10%); it is wiser to add 4 - 500 g to the maize silage plus urea, to limit the decline in performance.
For early maturing breeds, cereal supplements are not necessary, except during the last 2 or 3 months to improve the carcass and are mainly needed with low dry matter silages. For late maturing breeds, energy supplementation of maize silage is followed by slight improvement in growth rate, feed efficiency and carcass quality:
The rate of substitution of silage by concentrate was found to be higher with moist cereals than with dried cereals and with high dry matter silage than with low dry matter silage.
There was no difference in feed efficiency between ground dried grain and moist grain (either crushed and ensiled, or stored after propionic acid treatment and rolled) when maize grain amounted to 35 or 40% of DM intake. On the other hand, dried or moist maize grain had a much better utilisation when crushed before being fed to the animals. Maize ears dried or ensiled can replace maize grain as supplements to whole crop silage.
418 Maize ears of grain can be fed as the basis of a diet,
to which grain,some straw (0.5 to 1 kg per day) or hay ( 1 - 2 kg per day) is added. The growth rate is higher with ensiled ears and grain diets than with whole crop diets; feed efficiency is better for diets of ensiled ears (by 16% on average) and for moist grain diets (by 18.5% on average) than for the whole crop diets. Storage method for maize grain when grain is given ad libitum did not seem to have an effect on the growth rate, but feed efficiency is better with moist grain (by 10- 12%) than with dried grain and with ground grain than with whole grain (especially in the case of propionic acid treated grain for heavy animals).
In France, the development of maize cultivation has certainly allowed an acceleration in the organisation of youiig bull production in such a way that maize and maize silage are synonymous with modern cattle feeding.
Over the last few years many studies have been carried out on maize utilisation (whole plant, ears, grains or associations of these different parts). We are going to present here the main conclusions of the results obtained in France by INRA, ITCF or ITEB , for diets of whole crop maize silage and ears or grains ensiled or dried. A more complete review of this subject with a full list of references is given by Malterre (1976).
SUPPLEMENTING MAIZE SILAGE WITH HAY AND PROTEIN
a) The quantity and quality of hay offered When animals are given maize silage and hay ad libitum the
average hay intake varies between 0.5 and 2.0 kg/animal/day according to the quality of the hay. With medium or poor hay quality the reduction of energy supplied by the basal ration is followed by a lower growth rate and a lower feed efficiency than with maize silage alone. However, the conclusions may be very different with high quality hay. Thus, in 5 experiments, INRA was able to show that the provision of 1 kg good lucerne hay or grass hay would improve the growth rate by 60 or 130 g per day. The increase was higher with lucerne hay than with grass hay, and it seemed to be due to a higher DM intake.
419
b) Nitrogen supplements Crude protein supply; The more recent experiments carried
out in France have clearly demonstrated that the optimum levels are 850 - 900 g crude protein per day for dairy breed bulls (French Friesians, Normandes, Montbeliards, weaned at 13 - 12 weeks of age) between the weights of 150 and 550 kg. For bulls of beef breeds (from suckling herds and weaned at 7 or 8 months of age: Charoláis, crossbred Charoláis, Limousins, Salers, etc.) levels required are 1100 - 1150 g crude protein per day.
Nature of the protein source: Diets based on maize silage fulfil ideal conditions for a good utilisation of non-protein nitrogen such as urea. Nevertheless, according to some American experiments carried out on steers and some experiments in France with young bulls, the use of urea as the only nitrogen supplement for silage maize is followed by a big decrease in animal performance (about 9 - 10% for both growth and feed efficiency). However, the rations studied had a crude protein content ranging from 13 - 14% DM for animals whose live weight was greater than 275 kg; this fact led us, in certain cases, to go beyond the limits of classically-recommended urea level. No urea toxicity, however, was reported.
It seems, therefore, wiser (except when protein cake has a very high cost) to add from 400 - 500 g cake or 1 kg high quality dehydrated lucerne to the maize silage + urea for animals with a high protein deposition, as in the case of our French breeds. In these conditions the reduction of the animals' performance seems limited to 3 - 4%.
UTILISATION OF MAIZE SILAGE GIVEN WITH OTHER FORMS OF MAIZE
a) Level of concentrate in the ration When the quality of maize silage is good, it seems that a
concentrate supplement (about 2 kg per day) allows good utilisation of this silage. Now, it happens that the harvest and storage of the silage become, in certain conditions, great problems for the farmer who wants to fatten a great number of animals with whole crop silage. It then can become valuable to associate ensiled maize with a high quantity of grain-maize or ears, or.even to use almost exclusively grain-maize or ears. According to the results of American experiments, when large
420 amounts of concentrate are given, generally associating maize silage with maize grain or ears, the rate of substitution of silage by concentrate is very high: 87% on average. According to the results of French experiments, this ratio seems to depend on the processing (either dried or moist) of maize ears and of grain which supplements the silage. This ratio depends also on the breed of animal (dairy or beef).
In this way we were able to re-calculate the substitution rate between maize silage and ground dried cereal in the case of a supplement of ground dry ears or grain-maize, when the amount of concentrate associated with silage was greater than 1.2 kg DM/day. This substitution rate was between 66 and 83% for dairy breeds (the highest rates of substitution were obtained from maize richest in DM) and between 83 and 87% for cattle of beef breeds. What followed was an improvement in the live weight gain by 42 g - 70 g per kg DM of cereal given beyond 1.2 kg/day, whatever the animal. Consequently, for dairy breeds the feed efficiency was not improved, on the average, except when the DM content of the silage was low. For beef breeds, the feed efficiency was improved: -0.10 to -0.30 kg DM intake per kg of gain when 1 kg of cereal was given as a supplement.
On the other hand, when maize silage was supplemented with moist grain-maize (stored as silaqe after grinding or after propionic treatment and rolling) or with ground maize-ear silage, the substitution range for whole plant silage by moist grain was higher than that between whole plant silage and dried grain: from 87 - 100% for dairy breeds and 100 - 143% for beef breeds.
So the distribution of moist cereals, compared to the distribution of dried cereals was followed by a lower increase, even by no increase at all, in the level of intake of the animals of dairy breeds and by a decrease in the level of intake of those of beef breeds. Per kg DM of cereal given as a supplement to the dairy breeds the growth rate and feed efficiency were, nonetheless, improved (respectively 40 to 56 g per day and -0.15 to -0.25 kg DM intake/kg of gain). For the beef breeds, per kg DM of cereal given as a supplement, the improvement in growth rate ranged from 15 to 110 g per day (50 g per day as a mean) according to the experiment and the decrease in feed conversion ranged from 0.10 to 0.60 kg DM intake/kg of gain.
421 In conclusion, for late maturing breeds, all the results
seem to be in favour of a supplementation of whole-crop silage with moist maize grain or ears, since the growth rate was as high as with dried maize and the level of intake was lower. For early maturing breeds (mostly dairy breeds) energy supplementation of maize silage is less efficient and is relatively more advantageous with low dry matter silages.
b) Influence of the method of processing maize grain or ears when associated with whole-crop silage
The comparison between different forms of maize grain or ears when given ad libitum and associated with whole plant silage has been the purpose of very little work. In 4 experiments carried out by ITCF and by INRA-CARA (Figure 1), we did not find any difference in feed efficiency between ground dried grain and moist grain (either ensiled or crushed and stored with propionic acid) when grain-maize amounted to 35 or 40% of DM intake. The utilisation of moist maize grain seemed the same whether the grain had been stored with propionic acid and crushed, or ensiled. On the other hand, the dried or moist grain maize had a much better utilisation when crushed before being given to the animals (9 to 11% improvement in feed efficiency). After grinding, however, Tonroy et al. (1974) concluded from 5 experiments that, when given as a supplement to a ration of 8 kg maize silage (fresh material) the moist maize grain (ensiled or stored with propionic acid) was consumed in smaller quantities than the dried grain (the difference being 4 to 15% of total DM intake). Moist grain was then utilised better by the animals. Moreover, there' was no noticeable difference between whole grain and crushed grain.
These results appear sometimes contradictory, but as yet we do not have sufficient data. Moreover the most suitable form of presentation for maize grain seems to depend on the proportion of whole plant silage in the ration. Thus, dry maize whole-grain might be utilised better when the intake of maize silage does not exceed 0.5 kg DM per 100 kg live weight, but ground dried grain might be more valuable in the case of a higher level of maize silage intake.
Klosterman et al. (1962) and ITCF showed that, as a supplement to maize silage, ground dried ears were consumed in larger
422
Figure 1
FORM OF MAIZE GRAIN IN COMPLEMENT OF WHOLE PLANT SILAGE Ο Δ Ο
Concernent : %£* &
. Grein artificially dried
Ensued
form form 1300
-ΟΏ I200
. Prop. ac. treated _ Ear dried in cribs .Ensiled
MOO
IOOO
g/d AVERAGE DAILY GAIN
Λ y *"
òr' SS
<x kg DM/d. maize grain
kg kg
2.1
2,0
l,9
l,8
1,7
DRY MATTER INTAKE/ 100 KG BODY WEIGHT
D y *
12
π
ιο
ρ 0
τ 2
o 1 2 3 Z7/?K MATTER INTAKE/KG CARCASSA GAIN
s
o Δ * o f i
τΟ
I * ! »ι«
1 2 3
/?e¿ INRAandITCF
423
Figure 2
MAIZE STORED IN MOIST FORM
1400 Comparison between :
WHOLE PLANT SILAGE D (with or without cereal supplement) 1300
ENSILED EARS
ENSILED GRAINS 0 1200
GRAINS TREATED WITH PROPIONIC ACID e
Dairy breeds bulls
Beef breeds bulls
1100
1000
. s AVERAGE DAILY GAIN (g) ^
'" / / J^ / ' /
/ ' /
feed concentration
CK
"Ho* "io" 70 — [ —
SO
DRY MATTER INTAKE/100 kg (kg) J D.M. BODY WEIGHT
\
es·—.c. ^~^3
2,2
2,0
i.sH
1,6
CCï
* Ό
9
8
feed concentration Ίο 6"0 Ϊ'Ο W
DRY MATTER INTAKE/kg CARCASS GAIN
D — ^ " V . · ^ 'XD~iy&:3
* &
·>. V) feed concentration "NQ
■©
6Ό 70 6Ό
424 amounts than ensiled ears. However, owing to the slightly higher growth rate, the feed efficiency was very similar with the two forms.
UTILISATION OF GRAIN MAIZE OR MAIZE EARS GIVEN ALONE AND PRESENTED IN DIFFERENT FORMS
a) Utilisation of different forms of maize stored in moist condition: whole-crop silage, ensiled ears, ensiled grain or grain treated v/ith propionic acid
We have already considered successively the utilisation of the whole crop when given alone or associated with grain or ears and the utilisation of diets based on grain or ears. Many experiments have been done to compare the feeding .value of maize silage to that of ears or grain for growing or fattening steers. Here we present the first results obtained in France by INRA and ITCF (Figure 2).
In 8 feeding trials we compared the utilisation of ensiled maize ears to that of the whole ensiled plant. The growth rate of animals was higher (by 3 to 37%) with the diets of ears than with the whole crop diets. The voluntary food intakes were similar (-2% on average for ears) and ranged about a mean of 1.95 kg DM per 100 kg live weight for the whole-crop silage. Feed efficiency was better (by O to 24%; 16% on the average) for diets of ears than for whole-crop silage.
However, one must observe that with maize silage there are great variations in animal performances probably because of high variability in the whole-crop silage quality and these variations are greater than with moist ears or grain. One could conclude that the ears are clearly better than the whole plant silage.
The comparison of whole-crop silage with moist grain maize, either ensiled or treated with propionic acid, was studied in 6 feeding trials. As with the ears, maize grain had a better feeding value than the whole-crop silage: the growth rate of animals fed maize grain was higher by 8 to 9% (+ 160 g per day on the average) while DM intake was lower by 6.5%. Thus feed efficiency was greater by 14 to 22% (18.5% on the average) with maize grain, a difference slightly higher than that observed v/ith the ears.
425
Figure 3
DRY MATTER INTAKE/kg CARCASS GAIN
13
12
II-
10-
9
8·
7
O type laitier Δ type broutard
é^^JL
-τ 1 1 Whole Crushed Pelleted
DRY GRAIN
Ensiled Rolled Whole
MOIST GRAIN
426 b) Utilisation of maize grain or ears: effect of storage
and processing According to 13 feeding trials carried out in France by
ITCF and INRA (Figure 3), the method of storage or presentation of maize grain when the grain was given ad libitum, did not seem to have an effect on the growth rate of cattle of dairy breeds, which had always been very high (from 1200 to 1350 g per day according to the experiments). DM intake had always been greater with dried maize grain than with moist maize grain. Likewise it was greater with whole grain than with ground grain (especially in the case of dry grain). Thus, feed efficiency was better with the moist grain than with the dried grain.
On animals of beef breeds the differences between moist forms and dried forms seen greater than was the case for dairy breeds.
Here we have tried to compare the feeding value of different forms of dried and moist maize grain. We have not discussed the effect of technological treatments because they are very numerous and most of the time they do not induce a sufficient improvement in feeding value to compensate for the cost of treatment under French economic conditions.
CONCLUSION
Maize in different forms has great advantages and various ways of use. Using the whole plant or part of it, alone or in association, it is possible to make up diets varying in energy concentration according to the growth rate and the carcass weight to be achieved, to the economic conditions, farming conditions, and according to physiological stage, breed and genetic type of animals.
REFERENCES
Malterre, C. 1976. Different ways of utilising the maize crop for beef production. In: J.C. Tayler and J.M. Wilkinson (Editors) Improving the Nutritional Efficiency of Beef Production, Commission of the European Communities, Luxemburg.
427
Klosterraan, E.W., Johnson, R.R., Moxon, A.L. and Althouse, P. 1962. Feeding value of limestone-water treated ear corn silage with and without limestone treated whole plant corn silage. Ohio Agricultural Experimental Station Series No.128.
Tonroy, B.R., Perry, T.W. and Beeson, W.M. 1974. Dry, ensiled high-moisture ensiled reconstituted high-moisture and volatile acid treated high-moisture corn for growing-finishing beef cattle. Journal of Animal Science, 39 (5): 931-936.
Animal Feed Science ami Technology. 1 (1976) 429-440 4 2 9 tilsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
NUTRITIVE VALUE OF DEHYDRATED WHOLE-CROP MAIZE
Y. GEAY and C. MALTERRE Institut National de la Recherche Agronomique, Centre de Recherches Zootechniques et Vétérinaires, Theix, 63110 Beaumont, France
ABSTRACT
Dehydrated and processed maize is less digestible, but is ingested in greater quantities, than the standing or ensiled whole crop. Given ad libitum, the size of the differences depends on the processing method. The live-weight gain of animals which receive this feed is little different from that of animals receiving silage. As a result, the feed efficiency is lower. Its energy value for fattening is, then, between 0.6 and 0.7 FU/kg of dry matter (DM) inclusive. On the other hand, when given in limited quantities its energy value seems to be superior.
INTRODUCTION
For the past 10 years in France, lucerne and grass dehydration factories have been interested in whole-crop maize in order to extend their activity for as long as possible at the end of the season, and thus to reduce the amortisation expenses of their installations. The use of dehydrated maize for the production of beef was the subject of a number of different studies in our country, at the Institut National de la Recherche Agronomique (INRA) and at the Institut Technique des Céréales et des Fourrages (ITCF), until the energy crisis stopped all research activity in this area. Nonetheless, from all of the studies carried out in France as well as abroad, it seems that the food value of whole-crop dehydrated maize can be different from that of silage maize, and that it varies according to a number of factors that we are going to consider.
DIGESTIBILITY
Dehydrated maize can be processed into different forms that facilitate its storage and distribution:'wafers, cobs or pellets
430
that differ in particle size. The digestibility of the organic matter of dried maize pellets or cobs distributed ad libitum to sheep as the sole feed is much lower than that of the standing or ensiled plant, (Demarquilly and Andrieu, 1973). It has only been, on the average, 59.6% for 9 samples studied by these authors, and varied from 64.6 to 53.4% according to the fineness of grinding and the level of intake by the sheep. This poor digestibility essentially results from the reduction of time spent in the rumen and from the lowered cellulolytic activity of microorganisms , (Jarrige et al., 1973). This reduction affects the digestibility of cell wall constituents, much more notably the crude cellulose.
The reduction of digestibility brought about by comminution is much less when the maize is distributed in limited quantities due to a reduced rate of passage through the digestive tract (Demarquilly and Andrieu, 1973). In this way the digestibility of organic matter and crude cellulose, which were 60.0% and 25.8% respectively for 4 samples given ad libitum by the preceding authors, went up to 66.7% and 44% respectively for these same samples distributed in limited quantities. These results are close to those obtained by Cottyn et al. (1973) for 9 samples of dehydrated pelleted maize, given in limited quantities to sheep. Still the lowered digestibility of roughages due to grinding is more or less compensated by an improvement in the utilisation of metabolisable energy for growth and fattening. (Blaxter and Graham, 1956; Wainman et al., 1972).
Crude protein digestibility is more influenced by the level of intake. On the other hand, it is notably reduced by the effect of dehydration, especially when carried out under high temperature (Demarquilly and Andrieu, 1973; Karn et al., 1974). Nonetheless under the effect of heating, protein solubility in rumen liquor is lower, and as a result, the proportion of non-degraded feed proteins in the rumen and digested in the intestine increases.
QUANTITY INGESTED AND THE ASSOCIATED ANIMAL PERFORMANCE
From all the results obtained in France as well as abroad, particularly in Belgium, dehydrated maize turns out to be very well-ingested by animals (1.7 to 2.15 kg DM per 100 kg live weight)
TABLE 1 INFLUENCE OF NATURE OF THE PROTEIN SOURCE
EXPERIMENTS
Breeds Dry Matter (DM) (%) of the
standing plant Processing form
Diet composition (%) :
. Whole-crop maize
. Dehydrated lucerne
. Cereal
. Cake
. Urea
. Minerals
. Straw
. Hay
Number of animals Length of period (d) Daily gain (g/d) DM intake (kg/d) DM intake/kg of gain (kg) Carcass weight (CW) (kg) Killing out percentage Kidney fat (% of CW)
ITCF_J
Montbé
1976)
liard
44.5 Pellets
68.2 -
11.9 10.3 -1.6 8.0 -
12 304 1209 8.43 6.97 296 54.5 4.1
68.3 -
18.3 2.5 1.1 1.7 8.1 -
11 315
1186 8.45 7.12 302 55.0 3.9
ITCF-EDE (1970)
Friesian
Pellets
83.2 --7.3 0.9 --8.6
12 150
1200 9.85 7.50 292 53.7 -
89.8 ---1.8 --8.4
12 150 1246 10.11 7.43 298 54.3 -
ITCF (1974)
Normande
30.5 Pellets
61.9 18.1 -
11.6 -1.1 7.3 -
11 320 1206 8.18 6.78 287 54.8 4.2
74.8 --
16.3 -1.8 7.1 -
11 316 1288 8.47 6.57 300 55.1 5.1
TABLE 2 INFLUENCE OF LEVEL OF INTAKE ON DAILY GAIN AND EFFICIENCY
EXPERIMENTS
Breeds Dry matter (DM) (%) of the standing plant Processing form
Whole plant of maize
Diet composition (%) : . Whole-crop maize . Cereal . Cake . Minerals . Straw
Number of animals Number of days Daily gain (g/d) DM intake (kg/d) DM intake/kg of gain (kg) Carcass weight (CW) (kg) Killing out percentage Fat in the carcass Kidney fat (% of CW)
ITCF (1976)
Montbeliard
44.5 Pellets
Ad.lib
68.2 11.9 10.3 1.6 8.0
12 304
1209 7.76 6.41 296 54.5
4.1
-10%
65.6 8.4
12.9 1.6
11.5
12 327
1163 7.26 6.24 299 53.8
3.2
-18%
63.0 4.4
16.0 1.7
14.9
12 322
1195 6.82 5.71 303 54.2
3.1
Malterre et al. (1971)
Danish Friesian
47 Cobs
Ad.lib
88.7 3.7 6.8 0.8
15 117
1250 11.91 9.60
295 51.5 18.5
-10%
87.4 4.2 7.5 0.9
15 117
1126 10.70 9.61
295 52.6 17:2
Malterre et al. (1971)
Montbéliard
41 Pellets
Silage
68.8 10.4 10.4 1.0 9.4
12 199
1246 8.12 6.03 306 55.4 19.2
Pellets limited
65.4 11.5 11.5 1.2
13.7
12 200
1241 8.56 5.98 308 55.1 15.5
433
and allows high growth rates (1000 to 1400 g/day). Nonetheless, the results varied with a certain number of factors such as the proportion of grain in the whole plant, the nature of the protein source used, and the processing method. The proportion of grain in the whole plant.
This can be modified by the date of harvest, the date of sowing and the cutting height. An increase in the proportion of grain, due to a later harvest or an earlier sowing or even a higher cutting level, led to an improvement of feed efficiency (ITCF, 1971, 1972) (Fig.l). This was shown by either an increase in live-weight gain with no modification in ingested quantities (ITCF, 1971; Cordiez et al.,1975) or by a slight increase in live-weight gain, accompanied by a reduction in food "intake (ITCF, 1972). In fact, variations in grain content are accompanied by inverse variations in cellulose content (ITCF,1971, 1972). This goes along with the work of Gottyn et al. (1972) who showed that the net energy value of dehydrated maize varies as a function of cellulose content. Influence of the nature of the protein-source.
Whole-crop dehydrated or ensiled maize is low in nitrogen content, so it is necessary to supplement it in order to satisfy protein needs of young bulls during growth or fattening. This has been proved in the course of many studies using silage maize (Malterre, 1976) and verified with dried maize (Mattos, 1973). In France, ITCF carried out an experiment with young Charoláis bulls, and showed that a content of 13.5% crude protein in the DM was enough for these animals when their live weight was between 300 and 590 kg inclusive.
Diets based on dehydrated maize fulfil ideal conditions for a good utilisation of non-protein nitrogen such as urea. In fact, dehydration produces a significant drop in soluble nitrogen content in whole-crop maize (Zelter et al., 1971). Moreover the carbohydrate fraction that tends to provide rumen microorganisms with more readily available energy is considerably higher than in silage (Zelter et al., 1971) and thus allows a good utilisation of urea. As a result, contrary to what was observed with maize silage (Table 1), using urea as a supplement rather than protein cake does not result in a drop in live-weight gain or in feed efficiency (ITCF, 1970, 1974; Sibalic et al., 1974).
434
Fig. 1 Influence of the proportion of grain in the whole plant
1150
1100
1050
ïood
Daily gain (g/d)
of grain in the whole plant 10 20 30 40 50
2,7
2,6
2,5
2,4
η D.M. intake/100 kg body weight (kg)
% of grain in the whole plant
1
7,5
7,0
6,5
lD.M . in take/kg.o f gain (kg)
% of grain in the^wfaple plant 1 1 1 2 , > » *■
435
Fig. 2 Influence of processing method
"D.H. intake (kg/d) 12 11 IO·· y,. 8 7
Si = Silage W = Wafers C = Cobs Ρ = Pellets
Si
1500 140Q 130C' 120C, 110Ü·
1000
10. ^D.H. intake/kg of gain (kg)
9.
a.
Si W C Ρ Same plant used in the experiment Different plant used in the experiment
436
Dehydrated pelleted lucerne given with protein cake can be used as a protein supplement for diets of dehydrated maize and to reduce the amount of cake provided (ITCF, 1974). Yet, introducing dehydrated lucerne (18 to 19% crude protein) in the proportion of 60% of protein supplement produces a fall in live-weight gain and in feed efficiency, probably due to a reduction in the energy concentration of the feed. Influence of processing method.
In most of the experiments carried out, the utilisation of different forms of dehydrated maize was compared to that of ensiled maize, both being given ad libitum. From these comparisons, the following conclusions can be drawn.
(a) Dehydrated maize was always consumed in greater quantities than ensiled maize (Fig. 2 ) . The divergence was increasingly important as particle size decreased. Animals receiving wafers, cobs or pellets of maize actually ingested 107.5,115 and 121% respectively, of the quantity of DM ingested as silage.
(b) Dehydrated maize produced gains in live weight that were either slightly higher (107 and 110% respectively with cobs and maize pellets) or slightly lower (90.5% with maize wafers) than with ensiled maize.
(c) Feed efficiency was poorer with dehydrated than with ensiled maize. The DM intake per kg of gain accounted for 118, 108, 110% of the intake of silage, in wafers, cobs and pellets respectively. Moreover, the carcasses of animals receiving dehydrated maize were generally less fat than with silage.
The lower feed efficiency with dehydrated than ensiled maize is essentially due to a greater voluntary intake that led to a poorer digestibility. This assumption was confirmed in three experiments (ITCF, 1976; Malterre et al., 1971) in which DM intake of dehydrated maize was restricted to 82% of ad libitum. In this case the daily gain of animals was similar, but the carcasses of animals receiving dehydrated maize were less fat (Table 2 ) .
Among the different processing forms, wafers seem to be less profitable because of the significant drop in live-weight gain. On the other hand the differences between cobs and pellets are slight, which was confirmed by the results of experiments where these two forms were compared directly. However, pelleted rations always required a minimum supply of long fibre, generally provided
437
Fig· 3 Influence of the respective proportions of pelleted dehydrated maize and barley grain
ι r Daily gain (g/d)
1300
1200f
1100
^A—
o o (ITCFINA, 1968) « « (ITCFINA, 1970) Δ & (ITCF, 1974)
■ o
% of grain in_ the dist
i
2,5
2,0
10 20 30 40 50 60 70 'D.M. intake/100 kg of live weight (kg)
~* — · ~ Γ — ~~ ■— Δ - Γ " ι ii »
Δ % of grain in the diet
8!
7
6
<;.
10 20 30 40 50 60 70 D.M. intake/kg of gain (kg)
° a
^ ^ ^ = . Λ
% of grain in the diet to 10 20 30 40 50 60 70
438
by sträv; (about 10% of the total ration) to ensure maintenance of rumination and to limit parakeratosis, rumenitis and bloat.
NUTRITIVE VALUE
From all the results presented above it appears that, when dehydrated maize accounts for more than 70 to 80% of the DM in the diet, its energy value is from 5 to 20% less than that of maize silage depending on whether dehydrated maize is given in the same quantities as silage maize or ad libitum. The value would thus be between 0.6 and 0.7 FU/kg of DM inclusive if the mean value for silage is 0.75 FU. This lower energy value, when dehydrated maize constitutes practically the total diet, appears to be confirmed by values obtained in experiments carried out on dairy cows (Demarquilly and Andrieu, 1973).
On the other hand, when dehydrated whole-crop maize accounts for less than 50% of the fattening diet and is given as a substitute for grain (barley, Fig. 3 or maize) its energy value seems to be raised. It accounts for 81 to 90% of the value of barley (that is 0.8 to 0.9 FU/kg of fresh matter) in those experiments carried out by ITCF (ITCF, 1974; ITCF - EDE, 1970; ITCF - INA, 1968) and 78% of the value of maize grain (0.90 FU/kg of fresh matter) in an experiment done in Belgium (Boucqué et al., 1971). Still, the substitution value of dehydrated whole-crop maize would be expected to vary according to fibre content (from 0.82 to 1.02 FU/kg of fresh matter) as indicated in results obtained from 9 different samples. (Cottyn et al., 1973).
In conclusion, from the technical point of view, dehydrated maize could be very widely used for beef production. Indeed, when given ad libitum to animals during growth or fattening, it allows them to make high live-weight gains (1000 to 1300 g/day) with diets containing 80 to 90% of this product; moreover it offers the same advantages as other dehydrated roughages: harvesting facilities, handling, storage and distribution. In contrast with maize silage it can be sold easily and at any time.
What is more, as long as it is possible to limit animals, dehydrated maize has a feed value that is hardly different from that of maize silage, while it retains the above-mentioned advantages of dehydrated roughages. Finally, when given in place
439
of concentrated feed, its substitution value seems higher and superior to that of silage. Unfortunately its very high cost limits this use and the energy crisis removes any hope of improvement of this aspect.
REFERENCES
Blaxter, K.L. and Graham, N.M.C. 1956. J. Agrie. Sci., 47, 207217. Boucqué, Ch. v., Cottyn, B.G. and Buysse, F.Χ. 1971. Revue de l'Agric.
Bruxelles, 10, 12951314 Boucqué, Ch. V., Cottyn, B.G. and Buysse, F.X. 1973. Proc. 1st Intern. Green
Crop Drying Congress, Oxford, April 1973. 217227. Coehlo da Silva, J.F., Seeley, R.C., Prescott, J.Η.D., and Armstrong, D.G.
1972. Br. J. Nutr. 28, 357371. Cordiez, E., Bienfait, J.M., Lambot, O, van Eenaeme, C. and Pondant, Α. 1975.
Revue de l'Agric. Bruxelles. 2_, 315329. Cottyn, B.G., Boucqué, Ch.V. and Buysse, F.X. 1972. Revue de l'Agric.
Bruxelles, 9, 12511255. Cottyn, B.G, Joucqué, Ch.V. and Buysse, F.X. 1973. 5th Gen. Meeting of
European Grassi. Federation. Uppsala, June 1973. Demarquilly, C. and Andrieu, J. 1973. 24th Meeting of EFZ Vienne. 24/25'Sept. Jarrige, R., Demarquilly, C., Journet, M. and Beranger, C. 1973. Proc. 1st
Intern. Green Crop Drying Congr. Oxford, April 1973. 99118. Karn, J.Fl, Rumery, M.G.A., Clanton, D.C. and Jones, L.F. 1974. J. Anim. Sci.
38, 850853. Langlade, S and Malterre, C. 1974. Unpublished data. Malterre, C , Geay, Y., Bertin, G., Huguet, L. and Pelot, J. 1971. INRA Bull.
Tech. CRZV, Theix, 6 : 45. Malterre, C. 1976. Different ways of utilising the maize crop. "Improving
the nutritional efficiency of beef production". (Editors J.C. Tayler and J.M. Wilkinson) Commission of the European Communities, Luxembourg.
Mattos, J.C.A.D.E. 1973. Boletin de Industria Animal. 30 : 17. Sibalic, I..Kosanovic, M., Kunc, V. and Krajinovic, M. 1974. Zbornik Radova.
Institut Za Stocarstu Novi Sad. 7/8 : 75. Wainman, F.W., Blaxter, K.L. and Smith, J.J. 1972. J. Agrie. Sci. 78, 441447. Zelter, S.Z., CharletLery, G. and Tisserand, S.L. 1971. Ann. Zoötech. 20, 135. ITCF. Boigneville, 1971. Compte rendu d'expérience No. 11. ITCF. " 1972 " " No. 13. ITCF. " 1974 " " No. 33.
440
ITCF. Boigneville, 1974. Compte rendu d'expérience No. 50. ITCF. " 1976 " " No. 301. ITCF. " 1976 " " No. 404. ITCF. - EDE du Finistère, 1970 Compte rendu d'expérience Nos. 3 and 4. ITCF. ITCF. ITCF. ITCF.
1970 1970 1971 1973
ITCF. - INA. Vaux sur Aure, 1968 ITCF. " " 1970
No. 5. No. 6. No. 8. No. 12. No. 0. No. 3.
Animei Feed .Science ûnd Technology. 1 (1976) 441-454 4 4 1
I Iwvict Scientific Publishing Company. Amsterdam - Printed in The Netherlands
VOLUNTARY INTAKE AND EFFICIENCY OF UTILISATION OF WHOLE-CROP MAIZE SILAGE
J.M. WILKINSON The Grassland Research Institute, Hurley, Maidenhead, Berkshire, U.K.
ABSTRACT
The process of ensiling whole-crop maize is associated with major changes in composition which appear to be detrimental to nutritive value. Of particular significance is the production of organic acids and the degradation of plant protein to nonprotein nitrogen (NPN). Intake may be increased by restricting fermentation, and since less fermentation occurs in drier crops than in wet, immature crops, the ensiling of crops at dry matter contents of 30-35% is recommended. There is also an improvement in net energy as the crop matures, which is related to an increase in starch content and a decrease in cell wall content. The extent to which supplementary NPN can be exploited in diets based on maize silage is limited by low levels of energy intake, and a relatively high content of NPN in the silage as a result of the fermentation process. In the presence of supplementary energy, differences in utilisation between sources of supplementary nitrogen are minimal. Many experiments have confounded energy intake with source of supplementary N, and more research is needed to understand fully the factors affecting rumen microbial protein synthesis in productive cattle.
INTRODUCTION
Maize silage is an important feed for beef cattle in Europe, but the extent to which it is used could be substantially higher than the present level. A major attraction of the crop is that it can support a greater output of live weight gain per hectare than other feeds such as cereal grain or intensively managed grassland (Wilkinson, 1976). However, there are nutritional limitations to the use of diets containing maize silage. Some are associated with intrinsic characteristics of the plant (for
442 example, its low content of protein and minerals), others are brought about by the ensiling process. In this paper, the influence of ensiling whole-crop maize on its subsequent nutritive value is discussed, together with ways of rectifying its major nutritional disadvantage, that of its low content of crude protein.
THE ENSILING PROCESS AND ITS INFLUENCE ON THE NUTRITIVE VALUE OF WHOLE-CROP MAIZE
The conservation of whole-crop maize as silage is associated with two major compositional changes, namely, the conversion of water-soluble carbohydrates to short-chain organic acids and the degradation of plant protein to non-protein nitrogenous compounds (Johnson et al., 1967; Andrieu and Demarquilly, 1974b; Bergen et al., 1974). These two changes may have a marked influence on the nutritive value of ensiled maize, since there is evidence with grass silages that the level of free acidity (McLeod et al., 1970), the level of acetic acid (Jackson and Forbes, 1970; Demarquilly, 1973) and the content of ammonia-N (Wilkins et al., 1971; Demarquilly, 1973) can influence voluntary intake. Yet relatively little research has been conducted with maize on the influence of ensiling on its nutritive value. The data in Table 1 summarise the results of four experiments in which fresh (or frozen) whole-crop maize was given to ruminants ad libitum in comparison with the same crop in the ensiled form. Voluntary intake of maize silage is lower than that of the original crop, though the magnitude of the depression is variable. Possibly, the extent to which intake is depressed is a reflection of the amount of fermentation in the silo, which is greatly influenced by dry matter content (see next section).
TABLE 1 EFFECT OF ENSILING WHOLE-CROP MAIZE ON NUTRITIVE VALUE
Reference Noller et al. (1963) Dinlus et al. (1968) Andrieu and Demarquilly (1974a) Wilkinson et al. (1976)
% reduction due to ensiling Voluntary intake Liveweight gain
29 34 12 5 6 34
443 Live weight gain by cattle appears to be markedly reduced
as a result of ensiling(Table 1). This reduction may reflect a decrease in efficiency of utilisation of N, since Wilkinson et al. (1976) found that a lower proportion of ingested Ν was excreted in urine and a higher proportion of digested Ν was retained from frozen than from ensiled wholecrop maize. But more research is required to determine the significance to the nitrogen metabolism of cattle of the changes in nitrogenous constituents of wholecrop maize.
THE INFLUENCE OF DRY MATTER CONTENT ON THE NUTRITIVE VALUE OF MAIZE SILAGE
There is evidence that consumption of maize silage by cattle increases with increasing dry matter content (Huber et al., 1965; Huber et al., 1968; Johnson and McClure, 1968; Chamberlain et al., 1971; Malterre, 1976). Malterre (1976) concluded from a survey of 19 experiments that intake increased by 0.2 kg dry matter (DM) per 100 kg live weight (LW) between 20% and 35% DM content. Above 35 40% DM, intake decreased slightly. He also noted that younger cattle showed a greater response in intake than older animals.
Several possible explanations can be suggested for the response in intake to increasing DM content. Firstly, it may occur because cell wall content declines with advancing crop maturity as the ear component increases (Wilkinson and Osbourn, 1975; Penning, Wilkinson and Osbourn, unpublished data). This decrease is greatest as the dry matter content of the crop changes from 20% to 30%. Since the intake of forages is closely related to cell wall content (Osbourn et al., 1974), it is possible that intake is elevated in response to the decrease in the content of cell walls in more mature maize silage.
Secondly, intake may be increased because the extent of fermentation is less with drier crops than with wetter ones. The changes in the content of organic acids, and in the proportion of watersoluble (nonprotein) Ν in the total Ν of the crop as DM content increases are shown in Figure 1, which includes data from experiments in the USA and in Europe. Elevated levels of acidity in ensiled maize, brought about by
444
íííeci of dr« matter content on tk* tentent of oraanit, adii In tn&he øslate
14
total organic acids 7 PM 10
'O
ţj=l4)7017x * * *
20 30 40 50 drij malier content (7,)
60
H2O Soluble Ν ftíolalN)
Effect «ƒ art mûtUr contint o« th.« contint ci water -4olubl« nltroţcn In mail« »ilej*
50
40
35
30
25
20
ι$ = 7Οβ0Τ7χ ***
30 40 50 Dru, malter content ('/, )
Figure 1
60
445
addition of organic acids to the silage prior to feeding have been found to be reflected in reduced levels of intake (Emery et al., 1961; Dinius et al., 1968; Wilkinson et al., 1976). Partial neutralisation of maize silage with sodium bicarbonate (Thomas and Wilkinson, 1975) or ammonia (Thomas and Wilkinson, 1974; Cottrill et al., 1976) has given increases in intake by young cattle. Thus the response in intake to advancing maturity may reflect a reduction in acidity (Figure 1) as dry matter content increases.
Thirdly, reduced degradation of protein to non-protein nitrogen (NPN) compounds at higher DM contents (Figure 1) may be reflected in an increased supply of undegraded plant protein to the abomasum, and this may enhance the intake of silage (Egan and Moir, 1965). For example, Cottrill (Table 4) found that the intake of a diet of maize silage supplemented with insoluble protein (fishmeal) was 10% higher than when the silage was partially neutralised by an iso-nitrogenous quantity of ammonia.
Gross (1970)established close correlations between dry matter content and nutritive value in ensiled maize. He concluded that net energy value increased as dry matter content (and the proportion of ear in the crop) increased. This increase in energy value was attributed to the accumulation of starch in the ear and a decrease in cell wall content, as previously noted. In a recent experiment (Penning et al., 1976) we found that the live weight gain by young calves given a diet in which maize silage of 20, 29 or 38% DM comprised 70% of total DM intake, was respectively 703, 769 and 833 (Í 34) g/day for the low, medium and high DM silages. This significant increase in performance was not a reflection of DM intake, which showed only a slight response to the change in DM content. Further, the improvement in performance occurred despite a significant decrease in digestibility of the organic matter and of the cell walls of the diet as DM content increased. However, the proportion of the digested organic matter which was derived from digested cell walls decreased as DM content increased (averaging 52.1, 40.1 and 37.6% for low, medium and high DM silage, respectively). It is probable that this decrease was a contributing factor to an increase in net energy which was reflected in the improved animal performance from the high DM silage diet.
446 One problem in assessing the impact of dry matter content
on nutritive value is that the content of ear, and of' starch, in the crop is closely correlated with whole-crop DM content (Demarquilly, 1969; Wilkinson and Osbourn, 1975). As the plant matures, there is a decrease in the content of water-soluble carbohydrates and an increase in the content of starch in the DM (Demarquilly, 1969). Thus, apart from the change in DM content per se there is also a marked change in the composition of the DM. Attempts to identify the influence of varying the proportion of ear on nutritive value at similar whole-crop DM contents are unlikely to be very successful (see, for example, Andrieu and Demarquilly, 1974a) because of the simultaneous changes in composition and DM content which occur with advancing maturity. Yet there is clear need for research to establish the quantitative importance of the ear component in relation to the energy value of maize silage. Little calorimetrie work has been conducted on this subject, and the information is needed to guide plant breeders in their search for improved varieties of forage maize.
THE INFLUENCE OF SUPPLEMENTARY NITROGEN ON THE NUTRITIVE VALUE OF MAIZE SILAGE
There is evidence that addition of supplementary nitrogen is associated with increased intake of maize silage by cattle, though the extent to which the response occurs is likely to be influenced by the composition of the diet, the source of supplementary nitrogen and the age and weight of the animal. Thomas et al. (1975a) found that consumption of maize silage (10.6% crude protein) by calves of 240 kg average live weight was elevated by 11% following supplementation with urea, but older cattle (340 kg live weight) and younger cattle (140 kg live weight) gave little response in intake to additions of urea. In a subsequent experiment (Thomas and Wilkinson, 1975) we found that the response occurred in young calves only when the silage was partially neutralised with sodium bicarbonate. In the absence of quantitative data on ruminai microbial protein synthesis in cattle given diets containing maize silage and supplementary nitrogen, it is only possible to speculate as to
447 the reasons for the response or lack of response in intake to additional nitrogen. Andrieu and Demarquilly (1974b) noted that sheep gave a response in intake as the crude protein content of maize silage increased up to the level of 9-10% of the DM. Thereafter there was no response. This response in intake to level of protein was associated with a similar response in digestibility of organic matter. In our work with calves (Thomas et al., 1975a; Thomas and Wilkinson, 1975) we have not recorded large responses in digestibility of organic matter following supplementation of maize silage by urea. Possibly, rate of digestion is enhanced by addition of urea (rather than digestibility), allowing a greater level of consumption and an increase in the total supply of protein to the small intestine.
There is little doubt that the young ruminant responds in efficiency of feed utilisation to the supplementation of maize silage with nitrogen. For example, Thomas and Wilkinson (1975) found that addition of urea, (at 2% of the silage DM) to maize silage of 8.4% crude protein was reflected in a 70% increase in the proportion of ingested Ν retained. The calves were given silage as the sole feed at 2.3% of live weight. This observation suggests a response in microbial protein synthesis to the addition of urea. We found that the content of rumen ammonia nitrogen (NH3-N) in the calves given silage without urea was only 3 mg/ 100 ml, well below the level of 5 mg/100 ml which was suggested by Satter and Slyter (1974) as being necessary to maintain maximal microbial protein synthesis.
However, the high requirement for amino acid nitrogen to sustain rapid lean tissue growth in young calves may not be met even at maximum efficiency of microbial protein synthesis. This point is illustrated by experiments in which ammonia was added immediately prior to feeding to immature maize silage of low DM and high crude protein content. This was done to partially neutralise silage acidity and at the same time increase the content of nitrogen in the diet. When the silages were given ad libitum to young calves (100 kg live weight), intake increased by a maximum of 14.6% at the highest level of addition of ammonia (Table 2). The levels of rumen NH3-N rose from a relatively high basal level of 10.8 to 22.9 mg/100 ml with increasing level of addition of NH3. When the silage was subsequently given at a
448
TABLE 2 EFFECT OF ADDITION OF AMMONIA TO MAIZE SILAGE PRIOR TO FEEDING ON VOLUNTARY INTAKE OF DM, RUMEN ΝΗ-,-Ν AND BLOOD UREA-N
pH of silages Ν χ 6.25 (% of DM) Voluntary intake of DM(% of LW) Rumen NH^-N (mg/100 ml) Blood urea-N (mg/100 ml)
0 3.82 11.3
2.26
10.8
5.83
(1) *, **, *** significant effe respectively.
Level of to silage
0.32 3.95 13.3
2.29
12.4
9.27
ct of trea
NH3-N added (4 of DM)
0.53 4.27 14.6
2.43
18.6
12.5
tment at Ρ
0.80 4.60 16.3
2.59
22.9
14.9
<0.05,
SE
0.48**(1)
1.23***
0.64***
0.01 and 0.001
from Thomas and Wilkinson (1974)
TABLE 3 EFFECT OF ADDITION OF AMMONIA TO MAIZE SILAGE PRIOR TO FEEDING ON UTILISATION OF NITROGEN
Ν χ 6.25 in (% of DM) Intake of Ν Ν in faeces Ν in urine Ν retained Ν retained (% Ν intake) Rumen NF^-N, (mg/100 ml) Blood urea-N (mg/100 ml)
silage
(g/day) " " "
'
0
11.9 36.7 14.5 11.7 6.65
17.6
13.2
5.80
Level of NH3-to silage (%
0.64
13.8 40.8 14.6 20.4 2.57
6.4
23.5
11.2
-N added of DM)
1.20
17.1 52.5 14.7 29.9 4.60
8.6
37.5
15.5
SE
0.96*** 0.27 ns 1.15*** 1.055 ns
2.43*
1.29***
0.51***
Wilkinson (unpublished data)
449
restricted level of DM (1.9% of LW) there was no response in efficiency of utilisation of Ν to additional ammonia (Table 3). Since rumen NH3N levels exceeded 10 mg/100 ml in both experiments, efficiency of microbial protein synthesis was probably maximal. This relatively high level of ruminai NH3N in the calves given maize silage with no additional Ν probably reflected the relatively high level of watersoluble Ν (51% of total N) in the silage. In a subsequent production trial (Table 4) there was a large response in intake and performance to the feeding of fishmeal, compared to that from isonitrogenous levels of urea or ammonia, indicating a possible benefit to total protein supply of including a source of insoluble Ν in the diet.
TABLE 4 EFFECT OF ADDING UREA, AMMONIA OR FISHMEAL TO MAIZE SILAGE INTAKE AND LIVE WEIGHT GAIN BY YOUNG CALVES
(1) ON VOLUNTARY
Supplement
pH of silage Intake of DM (% of LW) Live weight gain(kg/day)
(1) . to give a conte
Urea
4.0
1.78
0.46
nt of Ν χ 6
Ammonia
5.0
2.39
0.39
.25 of 15% c
Fishmeal
4.0
2.63
0.97
f the DM
Fishmeal + NaHCOß
5.0
2.73
1.03
SE
.109
.066
Cottrill (unpublished data) In the presence of supplementary energy, on the other hand,
we have not detected significant differences between urea and fishmeal in their value as supplements of nitrogen for diets consisting predominantly of maize silage (Table 5). Since live weight gain was greater (by 20%) for the supplemented diets than for the control diet which contained the same level of concentrate, and since intake of DM was similar between the control diet and the rest of the diets, the results suggest that in the presence of supplementary energy, urea is utilised in microbial protein synthesis to give a similar total supply of protein to the animal to that provided by fishmeal.
Thus the scope for efficient utilisation of nonprotein
TABLE 5 EFFECT OF SOURCE, AND SITE OF ADDITION OF SUPPLEMENTARY NITROGEN ON VOLUNTARY INTAKE AND EFFICIENCY OF UTILISATION OF MAIZE SILAGE BY YOUNG CALVES
Site of addition:
Total Ν χ 6.25 (% of DM)
Dry matter intake (°¿ of LW) Live weight gain/ (kg/day) Live weight gain/ 100 kg DMI Live weight gain/ 100 g Ν intake
At ensiling Control Urea Fishmeal
12.8
2. 52
0.79
21.3
1.01
16.2
2.60
0.93
23.6
0.90
15.9
2.58
0.94
24.1
0.93
At feeding Urea Fishmeal
15.6
2.74
0.95
22.7
0.88
15.3
2.58
0.93
23.0
0.92
In concentrate Urea Fishmeal
15.3
2.63
0.96
23.8
0.97
14.9
2.62
0.96
23.3
0.97
(1) A 50% dried grass, 501 barley concentrate comprised 331 of the total daily DM intake of each treatment
Thomas et al. (1975b)
451 nitrogen appears to be severely restricted, by a deficiency in energy consumption, when maize silage is the sole source of energy in the diet. It may also be restricted by the presence of a large proportion of NPN in the silage, particularly when the silage is made from a relatively immature crop which has undergone extensive fermentation, as was the case in the experiments reported in Tables 2 and 3. In this situation, large responses in utilisation of maize silage by cattle may occur as a result of supplementing the silage with either energy or a source of insoluble protein such as fishmeal. However, further research is necessary to determine the relative values of different sources of supplementary nitrogen when given to cattle in combination with different quantities of supplementary energy.
CONCLUSIONS
Research is needed to establish more clearly the reasons for the depression in nutritive value which occurs when whole-crop maize is ensiled. Particular attention should be paid to the degradation of protein during ensilage and its impact on efficiency of utilisation of nitrogen by productive cattle.
There is need to define with greater precision the optimal nutritional regimes for the utilisation of NPN in diets containing maize silage. This work should involve studies of protein and energy digestion, and should take account of the close interrelationships between the two, since in many experiments differences in intake of energy have confounded comparisons between sources of supplementary nitrogen (see Thomas et al., 1975a).
Increased knowledge of the factors affecting the nutritive value of ensiled maize should facilitate more judicious use of supplements and enhance the efficiency of beef cattle production in Europe.
452
REFERENCES
Andrieu, J. and Demarquilly, C. 1974a. Valeur alimentaire du mais fourrage. II Influence du stade de végétation, de la variété, du peuplement, de l'enrichissement en épis et de l'addition d'uree sur la digestibilite et 1'ingestibilité de l'ensilage de mais. Annales de Zootechnie, 23, 1-25.
Andrieu, J. and Demarquilly, C. 1974b. Valeur alimentaire du mais fourrage. III Influence de la composition et des characteristiques fermentaires sur la digestibilite et 1'ingestibilité des ensilages de mais. Annales de Zootechnie, 23, 27-43.
Bergen, W.G., Cash, E.H. and Henderson, H.E., 1974. Changes in nitrogenous compounds of the whole corn plant during ensiling and subsequent effects on dry matter intake by sheep. Journal of Animal Science, 39, 629-637.
Chamberlain, H.C., Fribourg, H.A., Barth, K.M., Felts, J.H. and Anderson, J.M. 1971. Effect of maturity of corn silage at harvest on the performance of feeder heifers. Journal of Animal Science, 33, 161-66.
Cottrill, B.R., Osbourn, D.F., Wilkinson, J.M. and Richmond, P.J. 1976. The effect of dietary pH and nitrogen supplementation on the intake and utilisation of maize silage by young calves. Animal Production, 22, 154-55 (Abstract)
Demarquilly, C. 1969. Valeur alimentaire du mais fourrage. 1. Composition chemique et digestibilite du mais sur pied. Annales de Zootechnie, 18, 17-32.
Demarquilly, C. 1973. Composition chemique, characteristiques, fermentaires, digestibilite et quantité ingérée des ensilages de fourrages: modifications par rapport au fourrage vert initial. Annales de Zootechnie, 22, 1-35.
Dinius, D.A., Hill, D.L. and Noller, C.H. 1968. Influence of supplemental acetate feeding on voluntary intake of cattle fed green corn and corn silage. Journal of Dairy Science, 51, 1505-07.
Egan, A.R. and Moir, R.J. 1965. Nutritional status and intake regulation in sheep. 1. Effects of duodenally infused single doses of casein, urea and propionate upon voluntary intake of low protein roughage by sheep. Australian Journal of Agricultural Research, 16, 437-49.
Emery, R.S., Brown, L.D., Huffman, CF., Lewis, T.R., Everett, J.P. and Lassiter, C.A. 1961. Comparative feeding value of lactic acid and grain for dairy cattle. Journal of Animal Science, 20, 159-62.
453
Gross, F. 1970. Einfluss des erntezeitpunktes auf den futterwert von maisgarfutter. Das Wirtschaftseigene Futter, 16, 306-36.
Huber, J.T., Graf, G.C. and Engel, R.W. 1965. Effect of maturity on nutritive value of corn silage for lactating cows. Journal of Dairy Science, 48, 1121-23.
Huber, J.T., Thomas, J.W. and Emery, R.S. 1968. Response of cows fed urea-treated corn silage harvested at various stages of maturity. Journal of Dairy Science, 51, 1806-16.
Jackson, N. and Forbes, T.J. 1970. The voluntary intake by cattle of four silages differing in dry matter content. Animal Production, 12, 581-99.
Johnson, R.R., McClure, K.E., Klosterman, E.W. and Johnson, L.J. 1967. Corn plant maturity 3. Distribution of nitrogen in corn silage treated with limestone, urea and diammonium phosphate. Journal of Animal Science, 26, 394-99.
Johnson, R.R. and McClure, K.E. 1968. Corn plant maturity 4. Effects on digestibility of corn silage in sheep. Journal of Animal Science, 27, 535-40.
Malterre, C. 1976. Different ways of utilising the maize crop for beef production. In: J.C. Tayler and J.M. Wilkinson (Editors). Improving the Nutritional Efficiency of Beef Production. Commission of the European Communities, Luxemburg.
McLeod, D.S., Wilkins, R.J. and Raymond, W.F. 1970. The voluntary intake by sheep of silages differing in free-acid content. Journal of Agricultural Science, Cambridge, 75, 311-9.
Noller, C.H., Warner, J.E., Rumsey, T.S. and Hill, D.L. 1963. Comparative digestibilities and intakes of green corn and corn silage with advancing maturity. Journal of Animal Science, 22, 1135 (Abstract).
Osbourn, D.F., Terry, R.A., Outen, G.E. and Cammell, S.B. 1974. The significance of a determination of cell walls as the rational basis for the nutritive evaluation of forages. Proceedings of the XII International Grassland Congress, Moscow, Section 5, 514-9.
Penning, l.M., Wilkinson, J.M. and Osbourn, D.F. 1976. Effect of stage of maturity and fineness of chopping on the nutritive value of maize silage. Animal Production, 22, 153-54 (Abstract)
Satter, L.D. and Slyter, L.L. 1974. Effect of ammonia concentration on rumen microbial production in vitro. British Journal of Nutrition, 32, 199-208.
454
Thomas, C. and Wilkinson, J.M. 1974. The voluntary intake of maize silage treated with ammonia. Proceedings of the British Scoeity of Animal Production, 3, 102-3 (Abstract).
Thomas, C. and Wilkinson, J.M. 1975. The utilisation of maize silage for intensive beef production 3. Nitrogen and acidity as factors affecting the nutritive value of ensiled maize. Journal of Agricultural Science, Cambridge, 85, 255-61.
Thomas, C , Wilkinson, J.M. and Tayler, J.C. 1975a. The utilisation of maize silage for intensive beef production 1. The effect of level and source of supplementary nitrogen on the utilisation of maize silage by cattle of different ages. Journal of Agricultural Science, Cambridge, 84, 353-64.
Thomas, C. Wilson, R.F., Wilkins, R.J. and Wilkinson, J.M. 1975b. The utilisation of maize silage for intensive beef production 2. The effect of urea on silage fermentation and on the voluntary intake and performance of young cattle fed maize silage-based diets. Journal of Agricultural Science, Cambridge, 84, 365-72.
Wilkins, R.J., Hutchinson, K.J. , Wilson, R.F. and Harris, C E . 1971. The voluntary intake of silage by sheep 1. Inter-relationships between silage composition and intake. Journal of Agricultural Science, Cambridge, 77, 531-37.
Wilkinson, J.M. 1976, Forage crops versus grain crops In: J.C. Tayler and J.M. Wilkinson (Editors) Improving the Nutritional Efficiency of Beef Production. Commission of the European Communities, Luxemburg.
Wilkinson, J.M., Huber, J.T. and Henderson, H.E. 1976. Acidity and proteolysis as factors affecting the nutritive value of corn silage. Journal of Animal Science, 42, 208-18.
Wilkinson, J.M. and Osbourn, D.F. 1975. Objectives in breeding forage maize for improved nutritive value. Proceedings 8th Congress of Eucarpia, Maize and Sorghum Section, Versailles, France, September 1975
Animal Feed Science and Technology. 1 (1976) 455-464 4 5 5 (ilsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
THE DIGESTION AND METABOLISM OF THE ENERGY AND PROTEIN OF MAIZE
D.E. BEEVER
The Grassland Research Institute, Hurley, Maidenhead, Berkshire, SL6 5LR, England
ABSTRACT
This paper has attempted to review the carbohydrate and protein digestion of maize grain and maize silage fed to ruminants. Attention has been drawn to the ability of ground maize markedly to increase the supply of glucose to the tissues, as a result of an increase in the amount of starch which escapes ruminai degradation, whilst the possible inferiority of ground maize compared with flaked maize in relation to protein supply has been discussed. Theoretical calculations have indicated why maize silage is unable to supply adequate protein to meet the animal's requirements, and attempts to establish an optimal level of inclusion of protected prctein have been made. Further attention has been drawn to some of the factors influencing microbial activity within the rumen.
INTRODUCTION
The development of reliable techniques for the insertion of re-entrant cannulae into the alimentary tract of ruminants (Brown, Armstrong and MacRae, 1968) and an improved understanding and use of radioactive tracer techniques (Annison, 1964) has, over the last 10 years, led to a fuller elucidation of the mechanisms of rumen fermentation, and how the balance of the end products of digestion may be influenced by chemical or physical modification of the diet (Osbourn, Beever and Thomson, 1976) and frequency and level of feeding. It is not the intention of this paper to review the various reactions which occur in the rumen, and the subsequent digestive processes in the hindgut, but to consider some of the interesting features of maize grain digestion and, in the absence of any available data, attempt to construct a digestion pattern for maize silage.
45(>
MAIZE GRAIN
Whilst two forms of maize grain are generally available for feeding ruminants in the United Kingdom, the proportion consumed as flaked maize is considerably greater than the amount of ground maize used. Clearly starch comprises the major nutrient in all forms of maize grain, and MacRae and Armstrong (1969) observed with a hay:flaked maize diet (1:2 by weight), fed to mature sheep, an overall starch digestibility of 100%, with 90% of the (digestible) starch being lost within the reticulo-rumen. From the studies of Beever, Coehlo da Silva and Armstrong (1970), who fed a diet of 80% flaked maize, 20% dried grass, similar data were obtained, indicating 100% overall digestion, with 96% of this digestion occurring within the rumen. Thus it could be shown that for a total dry matter intake of 1 kg/day, of which flaked maize comprised 80%, the diet provided only 26 g of starch which was digested in the small intestine, but approximately 6.3 moles of rumen VFA, based on the stoichiometric data of Baldwin, Lucas and Cabrera (1970).
In contrast, when Beever et al". (1970) fed a similar diet but with the flaked maize replaced by ground maize, 139 g of digestible starch entered the small intestine, whilst VFA production from ruminai digestion of the cereal was reduced to a computed value of 5.0 moles/day. Whilst Beever et al. (1970) did not study the molar proportions of rumen VFA on the flaked maize and ground maize diets, there is evidence from other work, (Harrison, Beever, Thomson and Osbourn, 1975; Thomson and Beever, 1976, and D.E. Beever - unpublished observation) that the molar proportion of propionate is not influenced by the physical form of the grain. For twice-daily feeding situations, Harrison et al. (1975) and Thomson and Beever (1976) found a mean value of 30% propionate for flaked maize (60% of diet), whilst for ground maize which comprised 65% of the diet, D.E. Beever (unpublished observation), found a value of 29%. If VFA proportions can be extrapolated to VFA production rate (Armstrong and Prescott, 1970) then from the computed VFA yields, the yields of propionate can be derived. Assuming this is totally converted to glucose, then the total supply of glucose from propionate, and from glucose absorbed from the small intestine, was found to be 94 g/kg dry
457
matter consumed on the flaked maize diet of Beever et al. (1970) but 193 g/kg DM on the ground maize diet. The importance of this in terms of the animal's requirement is discussed by Armstrong and Prescott (1970) who calculated the minimal glucose requirement of a 590 kg cow yielding 20 kg milk of 4% fat and 4.7% lactose to be 1494 g/day. With a ration formulated to ARC (1965) requirements, of 50% hay, 7% soya bean meal and the remainder as rolled barley or ground maize, they concluded that glucose from the small intestine would provide only 15% of the glucose requirement on the barley diet, but 78% on the ground maize diet. Clearly large benefits can be derived from the feeding of ground maize when glucose requirement is high, such as in pregnancy or lactation, with an associated sparing of amino acids from gluconeogenesis although definitive experimentation on this latter aspect is not available.
The mechanism of this response with ground maize has eluded full elucidation. The size of the particle presented to the rumen may facilitate greater passage, as has been demonstrated with finely ground forages (Osbourn et al., 1976), whilst the possibility of an elevated flow of microbial polysaccharide, in particular that of protozoal origin, cannot be ignored. However, it is pertinent to note that attempts to reproduce this response with barley or wheat have proved unsuccessful (Ørskov, Fraser and Kay, 1969), and from this we may conclude that the physical form of the grain is responsible. Kerr (1950) demonstrated a horny endosperm in maize, quite different from barley grain, and in this respect a slowing down in the rate of raw maize digestion within the rumen might be expected; an effect which is probably negated when maize is heat treated in the flaking process prior to feeding.
Consideration of the protein supply of flaked and ground maize, however, reveals quite a different situation. With the two diets fed by Beever et al. (1970) the crude protein content (Ν χ 6.25) was 11.0% forthe diet containing flaked maize and 11.7% for that containing ground maize. However, despite a slightly higher intake of Ν on the ground maize diet, the amounts flowing at the duodenum and digested in the small intestines were greater on the flaked maize diet (see Table 1). It would appear that such values are related to the extra energy, and, in particular, the extra carbohydrate energy, digested in the rumen on the flaked maize diet, and possibly a slight increase
458 in the amount of cereal protein escaping rumen degradation on the heat-treated diet. In consequence, total protein uptake was 12 o higher on the flaked maize diet. When expressed as g truly digestible protein absorbed from the small intestine/MJ energy absorbed from the total tract (Thomas and Clapperton, 1972), the value for flaked maize (7.0) was higher than the value derived for the ground maize (6.3).
TABLE 1 THE MEAN QUANTITIES OF NITROGEN CONSUMED AND ENTERING AND LEAVING THE SMALL INTESTINE OF SHEEP
Nitrogen g/d: In feed At proximal duodenum At terminal ileum
Flaked maize
17.6 24.8 7.9
Ground maize
18.8 22.4 7.4
(Sheep receiving 1 kg dry matter per day of a flaked maize: dried grass or ground maize: dried grass diet, in which the maize component comprised 80% of the dry matter)
When compared with the calculated truly digestible protein requirements given by Egan and Walker (1975), assuming a BV of 75%, the flaked maize supplied sufficient truly digestible protein to meet maintenance requirements in cattle up to 400 kg liveweight or for 500 kg cows in the 5th month of lactation, whilst ground maize failed to meet the protein requirements of all classes of ruminant livestock reviewed by Egan and Walker (1975). In this situation, where flaked or, in particular, ground maize comprises a large part of the diet, recourse to supplementation of the diet with protected protein would be essential if requirements were to be met.
MAIZE SILAGE
The task of considering maize silage is made difficult by the absence of any published detailed digestion studies. Current experimentation at this Institute is measuring the quantity and composition of the end products of digestion of maize silage fed with varying amounts of urea or fishmeal, sufficient to pro-
459
vide 2.6% Ν in the dry matter. However, to date, no data are available. Clearly the composition of maize silage can vary according to the time of harvesting, the type of cutter used and the resulting ensiling process (Wilkinson, Penning and Osbourn, unpublished observation). For this paper I have considered material harvested at a dry matter content of 27 30%, with a precision chop harvester. The resulting silage has been shown to have approximately 28% starch and 25% cellulose, with a total organic acid content of 5.6%. Nitrogen content was found to be 1.4%, of which 10% was ammoniaN and 50% waterinsoluble N. In the absence of reliable data, it may be calculated that the supply of glucose to the small intestine on a diet of maize silage would be of the order of 50 g/kg dry matter consumed, assuming total digestion of starch within the alimentary tract and with 20% of this occurring postruminally. Clearly this value of 50 g exceeds the amount found on allcereal diets other than ground maize, and may be important when the values of 20% or so for the molar proportion of propionic acid of calves fed maize silage, reported by Thomas and Wilkinson (1975) are considered in relation to the animals' overall glucose economy.
The most controversial issue about the nutritive value of maize silage is regarding the protein content. Several workers (Thomas, Wilkinson and Tayler, 1975; Cottrill, Osbourn, Wilkinson and Richmond, 1976) have shown maize silage and urea to be an inadequate diet for calves less than 6 months of age, and have clearly defined the importance of including preformed protein in the diets fed to such animals. Clearly with its ,low Ν content and the large proportion which is nonprotein in origin, maize silage is most inadequate for meeting the protein requirements of the animal. From the data of J.M. Wilkinson (unpublished observation) it may be concluded that as much as 35% of the Ν in the crop is of nonprotein origin, with the true protein content of the crop being as low as 6%. With these assumptions, application of the data to the Metabolisable Protein model of Satter and Roff1er(1975), which is based on earlier work of Burroughs, Trenkle and Vetter (1974), achieved the data outlined in Figure 1. An estimate of absorbed (metabolisable) energy was derived from the data of Thomas and Clapperton (1972). The value of 5.6 g of digestible true protein/MJ ME was considerably less than the lowest value of
460
Fî$J Calculation oí the irtthţ diçee i íMr protein¡IK'S mtfobolhaMt CïlCrO^ 0$ matte Ç'ÛCLtt i^aíicr Sate r fi. RoØler 1975)
1 kiloçram maire silage drç matter
l4gNH3N
95a protein Ν Y Ξ 594$ protein
46a,N
Iluminai NH3 Pool' 4·6α,Ν 57s Ν «ι
Escapes Ruminai degradation
, _ U PLASM ¡ ''
ZS ~~Ί UREA POOL j
(microbial M) ».microbial
~ ^ Ν PW frZa,) 31 $
• *ιί*. » y JAECES ^ microbial tmeN *
55· δ a, microbial true protein
1 25· 8a, protein
IO· 8a,
43Oa, Digestible. 20·Ύα/
65·7α, D i b b l e True Protein ^ ^ ^ . ^
Calculated absorWd etiera^II^MJ/ka, DM iru* ?roïcinl^M£
461
6.7 given by Egan and Walker (1975) which they said was necessary to meet the protein requirements of 200 400 kg cattle at maintenance. Inclusion of fishmeal sufficient to raise the crude protein (Ν χ 6.25) content of the diet to 14% raised this value to 7.7, which was still insufficient to meet the protein requirements for growing lambs, but adequate for up to almost 1 kg liveweight gain per day in growing cattle. Further inclusion of fishmeal to a crude protein content of 16%, gave a computed value of 9.2, which from Egan and Walker's data would meet most protein requirements for growth, and in most instances would supply an excess.
Recent work at this Institute has been considering a range of factors likely to influence microbial synthesis within the rumen. McMeniman, Ben Ghadalia and Armstrong (1975) from a review of the literature concluded that on cereal diets the yield of microbial Ν in relation to organic matter (OM) digested within the rumen was 2.2 g/100g OM whilst a value of 3.3 g/100g OM was derived for forage diets. The mechanism responsible for such changes is not clear, although the work of Harrison et al. (1975) indicated that the turnover rate of the rumen fluid (dilution rate, Warner and Stacy, 1968) may be important. In this context, diets containing large amounts of cereals have inherently low dilution rates, whilst foragecontaining diets have much higher values. Recent work conducted in this laboratory has considered the effect on microbial protein synthesis of varying the ratio of readily available carbohydrate to structural carbohydrate digested in the rumen. The amounts of watersoluble carbohydrate and starch digested in the rumen were termed the o¿linked carbohydrate, whilst digested cellulose and hemicellulose were termed the /Q linked carbohydrate and diets were classified according to the oc : /β ratio. Preliminary data for a range of diets is shown in Table 2, indicating that as the o<. : & ratio increases so the efficiency of microbial synthesis declines. From the data of J.M. Wilkinson (personal communication) it can be concluded that the oc : £ ratio was of the order of 1:1, and from this we may conclude that microbial synthesis is highly efficient and may indicate why little response to additions of nonprotein nitrogen is obtained.
462
TABLE 2 RELATIONSHIP BETWEEN THE RATIO OF READILY AVAILABLE CARBOHYDRATE ( O". ) TO STRUCTURAL CARBOHYDRATE US> ) DEGRADED IN THE RUMEN, AND MICROBIAL DRY MATTER SYNTHESISED PER MOLE ATP PRODUCED (Y (ATP))*
Diet (with % compo
Ground maize (65) Rolled barley (41) Ground maize (25) Rolled barley (19) Grass pellet (57)
sition)
Dried grass (35) Formalin silage (59) Grass pellet (75) Lucerne (81) Grass silage (43)
CX. :xS
3.3 2.4 1.8 0.7 0.6
Y (ATP)
10.0 13.7 13.3 17.3 16.8
Data: D.E. Beever (unpublished observation) * Hobson (1965)
CONCLUSIONS
This paper has attempted to review information on the balance of the end products of digestion when maize grain or maize silage is consumed by ruminants, and how changes in digestion may influence the performance of animals. The importance of ground maize to supply extra glucose has been reviewed although attention has been drawn to its reduced protein nutritive value. With maize silage, theoretical calculations have indicated why the nitrogen of such a crop is inefficiently utilised, and the benefits that may be derived from supplementation with protected pro
tein sources.
REFERENCES
Annison, E.F., 1964. Absorption from the Ruminant Stomach. In 'Physiology of Digestion in the Ruminant' ρ 185. (ed. R.W. Dougherty) London, Butterworths.
ARC, 1965. Nutrient requirements of farm livestock 2. Ruminants. Agricultural Research Council, London.
Armstrong, D.G. and Prescott, J.H.D., 1970. Amount, physical form and composition of feed and milk secretion in the dairy cow. In "Lactation' ρ 349 (ed. I.R. Falconer), London, Butterworths.
463
Baldwin, R.L., Lucas, H.L. and Cabrera, R., 1970. Energetic relationships in the formation and utilisation of fermentation end products. In 'Physiology of Digestion and Metabolism in the Ruminant', ρ 319 (ed. A.T. Phillipson), NewcastleuponTyne, Oriel Press.
Beever, D.E., Coelho da Silva, J.F. and Armstrong, D.G., 1970. The effect of processing maize on its digestion in sheep. Proceedings of Nutrition Society, 29, 43A.
Brown, G.F., Armstrong, D.G. and MacRae, J.C., 1968. The establishment in one operation of a cannula into the rumen and reentrant cannulae into the duodenum of sheep. British Veterinary Journal, 124, 78.
Burroughs, W., Trenkle, A and Vetter, R.L., 1974. A system of protein evaluation for cattle and sheep involving metabolisable protein (amino acids) and urea fermentation potential of feedstuffs. Veterinary Médecine, (Small Animal Clinician), 69 (6) 713.
Cottrill, B.R., Osbourn, D.F., Wilkinson, J.M. and Richmond, P.J., 1976. The effect of dietary pH and nitrogen supplementation on the intake and utilisation of maize silage by young calves. Animal production, 22 (1) 154.
Egan, A.R., and Walker, D.J.,1975. Resource allocation and ruminant protein production. 3rd World Conference on Animal Production, Melbourne, May 1973, ρ 551.
Harrison, D.G., Beever, D.E., Thomson, D.J. and Osbourn, D.F., 1975. Man
ipulation of rumen fermentation in sheep by increasing the rate of flow of water from the rumen. Journal of Agricultural Science (Cambridge), 85, 93.
Hobson, P.N., 1965. Continuous culture of some anaerobic and facultatively anaerobic rumen bacteria. Journal of General Microbiology, 38: 167180.
Kerr, R.W., 1950. In 'Chemistry and Industry of Starch' New York and London, Academic Press.
MacRae, J.C. and Armstrong, D.G., 1969. Studies on intestinal digestion in the sheep. 2. Digestion of some carbohydrate constituents in hay, cereal, and haycereal rations. British Journal of Nutrition, 23, 377.
McMeniman, N.P., Ben Ghedalia, D. and Armstrong, D.G.,1974. Nitrogenenergy interrelationships in the rumen. Proceedings of the 1st. International Symposium of Protein Metabolism and Nutrition, Nottingham (in the press).
Ørskov, E.R., Fraser, C. and Kay, R.N.B., 1969. Dietary factors influencing the digestion of starch in the rumen and small and large intestine of early weaned lambs. British Journal of Nutrition, 23, 217.
464
Osbourn, D.F., Beever, D.E. and Thomson, D.J., 1976. The influence of physical processing on the intake, digestion and utilisation of dried herbage. Proceedings of Nutrition Society (in the press).
Satter, L.D. and Roffler, R.E., 1975. Nitrogen requirements and utilisation in dairy cattle. Journal of Dairy Science, 58, (8), 1219.
Thomas, C , Wilkinson, J.M. and Tayler, J.C., 1975. The utilisation of maize silage for intensive beef production. 1. The effect of level and source of supplementary nitrogen on the utilisation of maize silage by cattle of different ages. Journal of Agricultural Science (Cambridge), 84, 353.
Thomas, C. and Wilkinson, J.M., 1975. The utilisation of maize silage for intensive beef production. 3. Nitrogen and acidity as factors affecting the nutritive value of ensiled maize. Journal of Agricultural Science, (Cambridge), 85, 255.
Thomas, P.C. and Clapperton, J.L., 1972. significance to the host of changes in fermentation activity. Proceedings of Nutrition Society, 31, 165.
Thomson, D.J. and Beever, D.E., 1976. The effect of inclusion of mineral salts in the diet on dilution rate and the pattern of rumen fermentation. Journal of Agricultural Science (Cambridge) (in the press).
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Animal Feed Science and Technology. 1(1976) 465-479 4 6 5
tilsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
LEVELS, SOURCES AND METHODS OF NITROGEN SUPPLEMENTATION OF MAIZE SILAGE FOR BEEF PRODUCTION
A. GIARDINI, F. LAMBERTINI, F. GASPARI and A. LO BRUNO CNR - Centro di Studio per la Conservazione dei Foraggi, Agronomy Department, University of Bologna, Italy.
ABSTRACT
Results from some trials concerning protein supplementation of maize silage in beef cattle fattening are reported.
With 1% LW/day of concentrate in the diet no technical differences have been found between 11%, 13% and 15% crude protein content in the DM of the diet.
The protein levels (from 11 - 15%) proved to be independent of the energy content of the diet, giving similar results both in all-maize-silage diets and with the addition of 0.5 or 1% LW/day of concentrates.
Equal technical results are also found with traditional nitrogen supplementation with soya bean meal, and with urea given at feeding; there is a tendency for higher performances to be obtained by mixing the urea in the forage before ensiling.
With regard to this last subject, the comparison between two commercial NPN chemical additives (Pro-sil and Maisol-plus) and two experimental mixtures showed substantially similar results, slightly unfavourable to Pro-sil.
On the whole these results confirm the possibility of eliminating the vegetable proteins from beef cattle production and substituting them completely with NPN.
INTRODUCTION
During the last few years problems concerning protein supplementation in beef cattle fattening have become more and more important, following the more widespread use of maize silage as the basic feed. The protein content of this fodder is, in fact, insufficient to satisfy the nitrogen requirements of intensively reared beef cattle. Normally 1 kg/head/day of 35 - 40% crude protein (CP) supplements are used at feeding,
466
independently of the animal's weight and of the energy level of the diet. This gives rations with decreasing CP levels, from 14 - 15% for 200 kg bullocks to 11.5 - 12% for those of 450 kg, therefore with a mean around 13% for the whole fattening cycle.
Recent American research results (Beeson, 1975) suggest that a reduction in this level to 11% (from 12 - 13% to 9 - 10%) is advisable, with approximately similar technical results but improved economic results owing to the high cost of the protein feed. It has been said that these results could be justified in the type of animals raised on American farms, usually older steers, but we have not found proof of this interpretation in the experimental research on young bulls used in Italian and European fattening enterprises. The results of one of our trials (Giardini and Gaspari, 1975) presented last year at the Clermont-Ferrand Conference, indicated a certain trend towards protein levels higher than 11%, but these concerned very small differences which were only significant during the first period of fattening.
We feel therefore that the problem regarding the protein level for maize silage rations in beef cattle production still has not been defined sufficiently and that, for several economic and operational reasons, it would be interesting to verify the possibility of reducing the levels of nitrogen supplementation used up to now.
The nitrogen sources used most in Italy in order to formulate the supplements, are vegetable protein meals and in particular, soya bean meal.
The trends in the markets during the last few years, both regarding their acquirement and prices, have raised quite a few perplexities about future possibilities for using these products in beef cattle production. It is a widespread belief in fact, that man will not be able to continue to permit himself this luxury and will be forced to use these feeds either for just monogastric animals or, maybe, even for himself.
On the other hand, vegetable protein meals'are not indispensable for ruminants since these animals are capable of utilising NPN. It is well known that the common denominator of ruminant protein metabolism is ammonia, i.e. ammonia
467
represents an obligatory passage for most of the nitrogen substances contained in the feed whatever their nature is, whether proteins or not.
The number of NPN sources available and already proved in ruminant feeding (Belasco, 1954) is fairly high (about forty), but for a lot of reasons concerning efficiency, cost and possibility of acquirement, the most widespread in practice is urea. A certain degree of utilisation, even though much less important is indicated for biuret, ammonia and ammonium salts (Allen et al., 1971; Henderson, 1973; Henderson et al., 1970a, 1970b, 1971, 1972a, 1972b; Huber, 1973; Huber et al., 1972a, 1972b; Lichtenwalner et al., 1972; Piana, 1970).
In the USA, it has been calculated that in 1973, urea provided 50% of protein supplementation for beef cattle and 30% for dairy cows. In Italy, urea is used in the feed industry as well as on individual farms, but even though statistical data are lacking with regard to this problem, the general impression is that it is used in fairly modest quantities. The reasons for the farmers' timidness towards this product are well known: the use of urea raises several difficulties and some risks mainly connected to excessive rapidity of degradation in the rumen. Thus a high concentration of free ammonia is formed in the rumen, which in the best of the hypotheses causes nitrogen losses, but may also cause symptoms of poisoning and, in more serious cases, the death of the animal.
In order to limit these possible disadvantages, farmers are advised not to exceed 30% of urea nitrogen in the total diet nitrogen, to introduce urea gradually into the diet and to increase the frequency of feeding when urea is included.
All of these expedients are valid, but in practice they become a difficult task and do not always resolve the problem.
Safer results can be expected with the new methodology concerning the pre-ensiling application of urea. In a similar way to the mechanism in the rumen, urea in the silo is partly hydrolysed by the urease of bacteria to NH, and C02. The level of this degradation depends on the forage moisture content, i.e. from a minimum for very dry forage to a maximum value of 80% for forage harvested at the regular dough stage.
468 This transformation to ammonia has a double positive effect:
first of all on the fermentation process and then on nitrogen utilisation by the animal. In fact in the silo, ammonia is either used by the bacteria and transformed into microbial proteins, or else it combines with organic fermentation acids and forms ammonium salts. If there is a sufficient quantity of sugars, this process of acid neutralisation prolongs bacterial activity and results in a greater production of organic acids and, in particular, of lactic acid (Huber et al., 1968; Lopez et al., 1970; Maroadi et al., 1973; Polidori et al., 1973).
Thus a more stable silage is obtained (Henderson et al., 1970a) with a higher utilisation coefficient for the nitrogen along with lower toxicity, since there is already sufficient proof of a much slower rumen degradation of the organic acids and therefore a smaller quantity of ammonia enters the blood (Henderson, 1973; Ruminant Nitrogen Products Company, 1973).
Considering the normal sugar content in corn harvested at 30 - 32% DM, one should not exceed a rate of 0.5 - 0.6 kg of urea/100 kg of forage. This quantity increases the CP content in the forage DM from 8 - 8.5% to 12 - 13%, reaching nitrogen levels which are believed to be sufficient for beef cattle fattening requirements.
Several trials conducted during the last five years in the USA and those being carried out at present in Europe concerning maize, fully confirmed the value of these new methods, and some commercial chemicals for protein and mineral integration of the maize silage are already available.
Therefore, on the whole the problem of maize silage protein supplementation in beef cattle production still includes several features which have not been defined, such as levels, sources and methods of nitrogen integration.
During the last three years, all these aspects have been studied at the"Centro Conservazione Foraggi" with a series of experimental trials to evaluate even the possible interactions among the factors being considered. The trials were conducted on young bulls of different strains, raised in slotted floor housing or in paved feedlots, from an initial weight of 250 -300 kg to a slaughtering weight of 450 - 500 kg.
469
Since no significant interaction occurred among the trial factors (levels, sources and methods of use), the results are summarised as an average of each one.
PROTEIN LEVELS
Three rates of nitrogen supplementation: 11%, 13% and 15% CP in the DM, were compared in iso-energetic diets made up of maize silage + 1% LW/day of concentrate, usually shelled maize. Considering a 16% fibre content in the diet, the digestible proteins (DP) estimated on the basis of Leroy's coefficients (Leroy, 1935) were about 80, 95 and 110 g/FU respectively for the three levels.
The results obtained are given in Table 1, which includes a control group without protein supplementation.
TABLE 1 TECHNICAL RESULTS OF THE COMPARISON BETWEEN VARIOUS CRUDE PROTEIN LEVELS IN THE RATIONS (1)
""■*—^^ Treatments
Parameters " -^^^
Period I (74 days) Average daily gain (kg) Daily DM intake (kg) Feed efficiency Period II (74 days) Average daily gain (kg) Daily DM intake (kg) Feed efficiency Whole trial (148 days) Average daily gain (kg) Daily DM intake (kg) Dressing (%) Feed efficiency:
on body weight on carcass weight
Dietary crude protein
8 (control)
0.888 6.49 7.31
1.166 7.92 6.55
1.027 7.21 58.21
7.02 12.69
11
1.154 6.81 5.90
1.353 8.16 6.03
1.254 7.49 59.12
5.97 10.63
content (% of DM)
13
1.107 6.76 6.11
■ 1.279 7.98 6.24
1.193 7.37. 59.12
6.18 11.CO
15
1.099 6.76 6.15
1.319 7.97 6.04
1.209 7.37 59.50
6.10 10.79
(1) Data obtained from trials with a total of 144 head of cattle. The rations were represented by maize silage ad libitum + 1% LW/day of concentrates.
TABLE 2 TECHNICAL RESULTS OF COMBINATIONS OF THREE LEVELS OF CONCENTRATES AND THREE LEVELS OF CRUDE PROTEIN (1)
\ -^Levels of \ ^\energy \Le ve 1 s ^ \ ^ \ of crude^ \ protein
Parameters^
Trial length (139 days) Average daily gain (kg) Daily DM intake (kg) Dressing (%) Feed efficiency: on body weight
Feed efficiency: on carcass weight
All
11%
1.234
7.44 55.99
6.03
11.34
-maize
13%
1.178
6.70 56.60
5.69
10.58
silage
15%
1.225
6.78 56.23
5.54
10.37
Maize silage + 0.5% LW/day of concentrates
11%
1.369
7.78 56.84
5.68
10.52
13%
1.180
7.26 57.56
6.15
11.25
15%
1.248
7.27 56.91
5.83
10.78
Maize silage + 1% LW/day of concentrates
11%
1.392
7.73 58.54
5.55
9.98
13%
1.320
15%
1.346
7.84 7.47 | 57.91 | 59.13 I
i 5.94 5.55
10.80 i 9.88
All-maize silage
1.212
6.97 56.27
5.76
10.76
1 maize ! maize silage silage + 0.5% + 1% LW/day'LW/day
1.266
7.44 57.10
5.88
10.84
1.353
7.68 58.53
5.68
10.22
Averages
11%
1.332
7.65 57.12
5.74
10.61
1
13% ' 15%
! !
1.226 1.273
7.27 '7.17 57.36
5.91
10.88
57.42
5.64
10.34
(1) Six animals per group; the protein supplementation was by soya bean meal.
471
These results show the great importance that nitrogen supplementation of the maize silage rations assumes, with differences of about 20% on the technical results concerning daily gain and feed efficiency, in favour of the treatments with protein supplement added. They also showed that 11% CP in the DM of the diet was quite sufficient to fulfil the nitrogen requirements of young bulls in intensive rearing, at least within the weight limits which we considered.
A specific trial in factorial design was carried out to determine whether the energy level in the diet could interfere and modify the nitrogen requirements of the cattle, comparing the same three protein levels (11, 13 and 15%) in diets with three different energy levels (all-maize-silage, 0.5 and 1% LW/day of concentrates). The results given in Table 2 emphasise once again, the complete feasibility of the lowest level (11%) and without any interaction with the energy level of the diet, i.e. independently of this latter factor. This result could cause some perplexity, considering, as the results in Table 2 also show, the higher production of beef and therefore a greater protein requirement with a higher energetic level. In practice, however, with the increase in the ration's concentrate the fibre content is reduced and the digestion coefficients of the nutritive elements, including proteins, are increased. At an equal CP content in the ration, the DP increase with the increase in the ration's energy, whereas the DP/FU ratio remains almost unaltered.
The calculations made on the data from this trial, applying Leroy's digestibility coefficients (Leroy, 1935) show the validity of this concept.
Qualitative controls are being carried out on these same trials in order to verify any eventual effects that the protein and energy levels may have on carcass composition.
NITROGEN SOURCES AND METHODS OF USE
This paper only refers to two of the most representative and most widely used nitrogen sources in beef cattle production, soya bean meal and urea, this latter, both as a partial or total component of the "protein supplements" at feeding, or added to
47:
the forage before ensiling. The results given in Table 3 represent the averages of the
various trials with reference to the iso-nitrogenous and iso-caloric rations. In the treatments with urea the energy contribution of the soya bean was compensated by an equal quantity of dry shelled maize grain.
Kere too, no significant differences were recorded between treatments, showing that the nitrogen sources used are all equally suitable for protein supplementation of maize silage diets in beef cattle production.
TABLE 3 TECHNICAL RESULTS OF THE COMPARISON BETWEEN METHODS OF PROTEIN SUPPLEMENTATION AND NITROGEN SOURCES (1).
^ \ ' ~-— ___ Methods ^\. Nitrogen -^^
^ \ sources Parameters ^s.
Period I (83 days) Average daily gain (kg) Daily DM intake (kg) Feed efficiency Period II (61 days) Average daily gain (kg) Daily DM intake (kg) Feed efficiency Whole trial (144 days) Average daily gain (kg) Daily DM intake (kg) Dressing (%) Feed efficiency:
on body weight on carcass weight
At
soyabean meal
1.059 7.03 6.64
1.239 8.46 6.83
1.135 7.64 58.72
6.73 12.06
feeding
urea
1.053 7.08 6.72
1.178 8.35 7.09
1.106 7.62 58.80
6.89 12.33
time
soyabean + urea
1.023 7.21 7.05
1.241 8.49 6.84
1.115 7.75 58.79
6.95 12.44
Before ensiling
urea
1.133 7.15 6.31
1.225 8.35 6.82
1.172 7.66 58.68
6.54 11.73
(1) Data obtained from trials with a total of 120 head of cattle. The diets were represented by maize silage ad libitum + 1% LW/day of concentrates. The crude protein content was 11% of the DM.
473
Even urea at feeding furnished similar technical results to those obtained with soya bean and no evident symptoms of toxicosis were observed in any of the treatments, not even at the highest supplementation rates, equal to more than 150 g of urea/head/day. We feel that this result can be explained mainly by careful mixing and by the ad libitum feeding which guarantees a more gradual intake of urea by the animal, thus reducing the possibility of dangerous concentrations of free NH- in the rumen.
The results obtained with pre-ensiling urea also assumed particular practical interest mainly in view of the greater operative simplification of daily feed distribution.
However, the problems yet to be defined are numerous: problems regarding storage processes, formulation and distribution of the chemicals.
The problem concerning the different chemicals for pre-ensiling maize silage treatments was studied in three different trials; results are given with regard to the 1974 trial only, since these results were the most complete and significant. In this trial two commercial chemicals (Maisol-plus based on urea, and Pro-sil based on ammonia) and two of our experimental mixtures of which one (CCF 2) with complete mineral integration and the other (CCF 1) with just urea and sodium chloride, were compared.
On the whole, conservation of regular maize silage treated with nitrogenous additives does not seem to present particular problems. Compared to the control maize silage, the treated forage shows a higher lactic and NH, content, whereas the DM losses and the acetic and butyric content remain almost unaltered. The increase in the lactic acid content reached statistically significant values (+ 46% vs the control) with Pro-sil only, (Table 4) whereas with the urea chemicals these increases (from 12% - 16%) did not reach significance. This different trend appears to be justified by the higher sugar content of the maize silage treated with Pro-sil (this product contains 62.8% of molasses) which permitted a prolongation of the fermentation processes.
The NH, content was very high in all the treated forages (3-4 times greater than in the control) with a tendency to
TABLE 4 TRENDS IN STORAGE PROCESSES WITH VARIOUS NPN PRE-ENSILING ADDITIVES
\Parameters Maize^s.
silage\> treatments^
Control Pro-sil Maisol-plus CCF 1 CCF 2
Green fodder
DM (%)
34.43 32.04 34.57 •35.69 34.09
Losses of DM (%)
6.61 2.94 4.17 6.04 6.32
Fermentation acids (in % of DM)
lactic (1)
7.76 Bb 11.32 Aa 8.99 ABb 8.71 ABb 8.96 ABb
acetic (2)
2.86 2.77 2.67 3.07 2.38
butyric
0.05 0.04 0.08 traces 0.12
pH (1)
3.79 4.30 4.30 4.51 4.10
Be ABab AB ab Aa ABbc
NH -Ν (% in
total N) (1)
8.03 26.55 Cb 28.54 BCb 34.06 Aa 31.78 ABa
Urea Ν (% in
total N)
trace trace 4.08 4.22 5.14
Evaluation
Score
91 98 96 91 96
Quality
Excellent It
" " "
(1) Values having different superscripts differ significantly Α,Β, (P <0.01); a,b, (Ρ <0.05), (2) No significant difference.
TABLE 5 RESULTS OF COMPARISON BETWEEN VARIOUS NPN PRE-ENSILING ADDITIVES
475
parameters —
Period I (90 days) Crude protein (% of DM) Average daily gain (kg) Daily DM intake (kg) Feed efficiency Period II (45 days) Crude protein (% of DM) Average daily gain (kg) Daily DM intake (kg) Feed efficiency Whole trial (135 days) Crude protein (% of DM) Average daily gain (kg) Daily DM intake (kg) Dressing (%) Feed efficiency:
on body weight on carcass weight
Pro-si1
10.75 1.044 7.09 6.79
10.30 1.136 8.04 7.08
10.60 1.075 7.40 57.89
6.88 12.51
Maisol-plus
10.53 1.233 7.30 5.92
10.20 1.067 8.57 8.03
10.40 1.178 7.72 58.17
6.55 11.85
CCF 1
11.44 1.122 7.03 6.27
10.85 1.289 8.53 6.62
11.20 1.178 7.53 58.16
6.39 11.57
CCF 2
11.15 1.222 6.84 5.60
10.56 1.133 8.CO 7.06
10.94 1.193 7.23 58.25
6.06 10.95
TABLE 6 COMPARISON AMONG SUPPLEMENTS WITH OR WITHOUT VITAMINS A AND D,
■ Treatments Parameters ^^__^
Number of cattle Average daily gain (kg) Daily DM intake (kg) Dressing (%) Feed efficiency: on body weight
on carcass weight
Without A+D,
28 1.324 8.48 58.33 6.40 11.55
With A+D.
28 1.312 8.36 58.78 6.37 11.41
476 rise with the increase in the quantity of urea added.
These results, together with the higher pH values of the NPN-treated silage, would tend to indicate greater storage difficulties, even though the evaluation made with the Flieg method showed that the silage quality was "excellent". Problems could arise, practically, in the storage of riper forage, known to have less sugars.
From the beef cattle production point of view, (Table 5) all the trial chemicals furnished similar technical results concerning daily gain and feed efficiency, with a slight disadvantage, even though not significant, for Pro-sil. The experimental formula with just urea and sodium chloride furnished satisfactory results, above all in the last stage of fattening, whereas during the first stage of fattening the lack of mineral salts influenced the animals' performance negatively. In a final analysis, therefore, mineral supplementation of maize silage diets only seems to be indispensable for young animals.
Another problem discussed concerning the correction of the qualitative deficiencies of maize silage,is whether vitamin A is needed or not, also because of the difficulties involved in including it in the pre-ensiling chemicals. The results we obtained (Table 6) do not show any necessity for this type of supplementation, proving that the carotene content of maize silage and dry shelled grain rations is sufficient to satisfy the vitamin A requirements of young bulls weighing more than 200 - 300 kg. These results confirm the indications furnished by American authors (Michigan State University, 1969; Ruminant Nitrogen Products Company, 1973), with whom we agree concerning the possibility of being able to formulate complete pre-ensiling chemicals capable of correcting all the maize silage deficiencies in beef cattle production.
CONCLUSIONS
On the whole these trial results tend to indicate that the level of 11% CP in the DM, equal to about 80 g of DP/FU represents the optimum level for maize silage diets in the production of beef cattle weighing more than 250 kg LW, and that the problem concerning protein supplementation is mainly
477 a problem of nitrogen quantity, independently of the sources used (whether proteins or not), of the method of distribution (at feeding or pre-ensiling) and of the energy level of the diet.
In practice, therefore, considering the normal maize silage nitrogen content (8 - 8.5% CP in the DM) this means supplementing the diet with 200 - 250 g of CP per head/day, equal to 500 -600 g of soya bean meal or to 80 - 100 g or urea for the whole fattening period. These two products furnished, in fact, technical results which are very similar, showing the practical possibility of completely eliminating vegetable protein meals in the diet of the beef cattle, and using NPN as the exclusive Ν supplement.
The new methods for the treatment of 'maize silage before ensiling with additives based on NPN and mineral salts are considered interesting today. In this sector, the problems to be defined are still numerous: problems of the choice of the product, formulation problems (liquid, granular or powder) and, last but not least, practical problems of distribution in order to ensure uniformity of mixing without slowing down harvesting and ensiling operations. Some justified problems could be raised concerning the possible disadvantages of forage conservation particularly for the riper forage. In fact, for these the low soluble sugar content could stop the fermentation process at a pH which is too high and dangerous for good conservation. These disadvantages could be reduced by the use of NPN additives based on acids or else containing sugar (Pro-sil), but their distribution causes considerable practical difficulties.
Interesting results were obtained in preliminary trials conducted at the Institute of Nutritional Sciences of the University of Piacenza with the use of amylase.
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Beeson, W.M., 1975. Purdue research applied to finishing beef cattle. Communication presented at the 1975 Purdue Feed Industry Conference, Purdue University, West Lafayette, Indiana, USA.
478
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479
Maroadi, Α., Piva, G., Caprioli, G., 1973. Sull'utilizzazione dell'azoto non proteico ad opera dei microrganismi responsabili delle fermentazioni degli insilati. (Ricerche condotte con N). Alimentazione Animale, 5:43.
Michigan State University, 1969. Corn silage. Production - harvest -storage in Michigan. Co-operative extension service. Bulletin E-665.
Piana, G., 1970. L'impiego zootechnico del fosfato biammonico. Alimentazione Animale, 2:61.
Polidori, f., Zamorani, Α., D'Urso, G., Russo, C , Galvano, G., Cataldi Lupo, M.C., Dell'Aquila, S., Lanza, C.M., 1973. Sulla composizione dello insilato di mais a vari stadi di maturazione. Nota I. Effetti dell'aggiunta di urea. Alimentazione Animale 5:21.
Ruminant Nitrogen Products Company, 1973. A feeder's guide to growing, harvesting, treating, storing and feeding corn silage. PO Box 206, Adrian, Michigan, USA. 49221.
Animal Feed Science Technology. I (1976)481-484 481 Elsevier Sdentine Publishing Company, Amsterdam - Printed in The Netherlands
THE NUTRITIVE VALUE (ENERGY) OF MAIZE SILAGE
A.J.S. VAN ES, * ** Y. VAN DER HONING,* and H.A. BOEKHOLT,** * Institute for Livestock Feeding and Nutrition Research "Hoorn",
Lelystad, The Netherlands ** Department of Animal Physiology, Agricultural University,
Wageningen, The Netherlands
INTRODUCTION
The nutritive value of a feed for a given combination of maintenance and production depends on its content of meta-bolisable energy (ME) and the efficiency (k) of the utilisation of this ME for maintenance(k ) and production (k for beef cattle,
m g k. for lactating cows).
THE ME CONTENT OP MAIZE SILAGE
We found an average gross energy content of 4.7 Meal per kg organic matter of maize silage. It compares well with the figure of 4.65 of Demarquilly and Andrieu (1975) for fresh maize.
In the conversion of gross energy to ME, three factors,play a part: (1) stage of growth of the maize, (2) animal species (cattle or sheep) and (3) level of feeding. At more mature stages of growth, stems and leaves become less digestible. This is compensated for by the steadily increasing grain content, since maize grain has a very high digestibility. Thus, with advancing stage of growth there is only a small change in crude fibre content and digestibility of the whole crop, especially after the maize ears start developing.
Usually digestion trials are performed using sheep, to study differences in digestibility. Cattle chew maize grains less thoroughly than sheep; this results in more grains reaching the duodenum in cattle. The higher the feeding level and the more mature the maize, the greater is the quantity of grains and grain particles not completely digested in the intestinal tract of cattle. Differences up to 5 units in organic matter digestibility between high-yielding cows and sheep may occur.
In beef cattle feeding level is not extremely high, e.g. 2.0 - 2.5 times maintenance, so differences of about 3 units may
482
occur between fastgrowing beef cattle and sheep at maintenance. However, there appears to be a considerable betweencattle variation with regard to this effect: some cattle digest the grains nearly as well as sheep.
In 4 experiments including 27 balance trials with dairy cattle producing about 20 kg milk daily and consuming 02 kg hay, 610 kg maize silage dry matter and 16 kg concentrates, the urinary, methane and metabolisable energy of the rations were 2.7 3.8, 6.1 7.0 and 57 62% of the gross energy respectively.
Energy digestibilities varied from 66 to 72%. ΜΕ/DE ratios were 85 86%. In the trials of Leahey et al. (1973) energy digestibility was 68.7 and the KE/DE ratio 84. They fed maize silage to dry cows at levels slightly above maintenance.
Digestibility and ΜΕ/DE ratio were 65 and 86 respectively in the trial of Tyrrell and Moe (1972) with cows producing 20 kg of milk for the 70% maize silage ration and 66.5 and 89 for the 40% maize silage ration.
In their earlier trial, Moe and Tyrrell ,(1972) , with dry and lactating cows together yielding on average 13 kg milk the two figures were 68.4 63.0 and 84 86 (higher value in the lov/ protein ration).
Burlacu (1975) fed maize silage and concentrates in a 85:15 ratio to growing heifers; energy digestibilities averaged 66.8 and the ΜΕ/DE ratio was 82.5%.
In beef cattle at lower protein levels as physiologically required in their ration less Ν is voided as urea with the urine than in lactating cows. This tends to increase the ME/DE ratio somewhat. At milk yields above 1015 kg, requiring a feeding level higher than the average feeding level of beef cattle with daily gains averaging 1 kg, methane energy losses tend to decrease; thus in beef cattle at their lower feeding level this ratio becomes lower. As beef cattle generally receive more protein than physiologically is required the overall result is a slightly lower ΜΕ/DE ratio. Therefore correcting the abovementioned dairy data to beef cattle data gives a ratio estimate of 83 84%. Energy digestibility for rapidly growing beef cattle might be close to 68 if the above data are corrected for feeding level.
483
THE UTILISATION OF ME OF MAIZE SILAGE IN DAIRY CATTLE AND GROWING BEEF CATTLE
There is little information on the utilisation of the ME for maintenance and growth of beef cattle fed maize silage. However, for lactating cows a limited amount of information is available. The 27 Netherland trials gave efficiencies for milk production of 56 - 63% at an estimated maintenance requirement of 117 kcal ME/kg'1
Leahey et al. (1973) found an improbably high figure of 80% for growth at a maintenance requirement of 122 kcal ME/kg in their dry cows.
Tyrrell and Moe (1966) give 61% for the high and 54% for the low concentrate silage ration for milk production, maintenance estimates being 111 and 95 kcal ME/kg respectively.
In their earlier trial it amounted to 60%, with a maintenance estimate of 111 kcal ME/kg
In Burlacu's work with growing heifers an efficiency for growth of 60% is computed by regression, but this computation gives an improbably high value of 150 kcal ME/kg for maintenance.
Van Es (1976) assumes that the efficiency for milk production is 10 - 15% above the one for tissue fat synthesis. Assuming this to be true we might correct the data of lactating cows given above:
Corrected Measured efficiency efficiency
Netherlands (1975) 52% Leahey et al. (1973) 80%(?) Tyrrell and Moe (1972) 53%, 47%
" (1972) 56% Burlacu (1975) 60%(?)
Taken together this suggests an efficiency of the utilisation of the ME of the maize silage for growth of 50 - 55% and a maintenance requirement of about 110 kcal ME/W for tethered beef cattle. Due to the small variation in ME content of the gross energy of maize silage it is hardly to be expected that both figures will vary much for different batches of maize silage.
484
CONCLUSION
For a first approach of the energy value for growth (young beef cattle) it is sufficient to know the ME content of the maize silage provided the assumption of a 10 15% lower utilisation of ME for beef compared with milk production is correct.
The ME content of the gross energy could be assumed to be on average 83 84% of the DE content, the latter being close to 68o.
As the gross energy of the organic matter is close to 4.7 Meal, organic matter would have an ME content near 4.7 χ 0.68 χ 0.835 = 2.7 Meal.
Determination of the in vivo energy digestibility with beef cattle would, of course, give a more reliable ME figure.
REFERENCES
Burlacu, Gh., 1975. Private communication. Demarquilly, C and Andrieu, J., 1975. Private communication. Es, A.J.H, van, 1976. Factors influencing the efficiency of energy
utilisation by beef and dairy cattle. In: Principles of cattle production, p. 237253. Proc. 20th Nottingham Easter School, Swan, H. and Broster, H.W. (eds.), Butterworths, London.
Leahey, J.M., Holter, J.B. and Urban, W.E. Jr., 1973. Energy and protein utilisation in forages fed to dry cows. J. Dairy Sci. 56: 587591.
Moe, P.W. and Tyrrell, H.F., 1972. Net energy value for lactation of highand lowprotein diets containing corn silage. J. Dairy Sci. 55: 318324.
Tyrrell, H.F. and Moe, P.W., 1972. Net energy value for lactation of a high and low concentrate ration containing corn silage. J. Dairy Sci. 55: 11061112.
Animal heed Science aiul Technology. 1 (1976) 485-501 4 8 5 I Iscvicr Scientific Publishing Company, Amsterdam - Printed in The Netherlands
DISCUSSION ON SESSION k
W. Kaufmann West Germany
I would like to make some remarks which could be useful for the discussion of what we heard this morning. There are different influences and the most important point is the energy supply from maize silage for our animals. So there was comment on silage, on whole crops and on grain silage. What are the factors of these different kinds of silages which might have an influence in the digestive tract and from there an influence on the energy supply? First, there is protein content. We heard a lot on this. There might be an effect of DM content and physical structure. These factors might affect rate of passage through the digestive tract, especially through the stomach and the fermentation pattern in the rumen. There are some results where fermentation pattern is influenced to give a higher propionic acid content.
All of these factors may influence intake, plus or minus, they may influence efficiency of utilisation of metabolisable energy, as we heard from the paper by Van Es, and all this influences energy supply.
There were also those who measured digestibility or protein content or both; or those who measured rate of passage and not digestibility and those who measured both, either relating it to intake or not.
T. Cobic Yugoslavia
In opening discussion on the papers presented, there are obviously certain problems which need to be explained and discussed in detail. First of all, there are two aspects of the whole problem, one of a biological nature and the other concerned with the economics of using different forms of maize. Extensive studies were conducted on utilisation of maize silage and dehydrated pellets in feeding to beef cattle and the higher digestibility was found for maize silage than for dehydrated pellets. Consequently, utilisation of dry matter of silages was more efficient. Feed cost price was also against the dehydrated pellets. This method of conservation is almost
486
abandoned in some countries owing to the high cost of fuel which is still increasing. The importance of maturity stage in the harvesting of the maize crop was emphasised and crop yield was found to be the most important factor.
It seems that from the standpoint of utilisation of maize several topics must be considered but the most important are those of production of energy per hectare or production of beef, or number of fattening cattle, per hectare.
Similar problems of evaluating maize ensiled at different dry matter contents were studied and there was no significant correlation between digestibility coefficients of normally developed maize and the principal criteria of the age of the plant at harvest.
New technology of harvesting maize as shelled grain, which is much more efficient from the point of view of maize production alone instead of corn ears, represents a typical example of difficulties we have in providing a" suitable feed for fattening animals, because cobs and stalks are left on the field. Since there is about 20% of cob in the ear, taking the total area of corn it is a considerable waste of roughage.
Dry matter intake of maize silage is important in the fattening of animals as one of the limiting factors of using this form of maize as a feed for cattle. However, alterations were given with respect to DM content, since maize silage intake increases with the DM content, but still it does not affect live-weight gains.
Technological treatments of maize and different forms of plant, ear or silage, made from the whole plant, ensiled ears and grains are of considerable interest, especially for countries with early frosts and those using varieties with a long vegetative period. Having in mind growing capital investments in storage and in the machinery needed, it seems that this problem requires further study.
Every form of conservation of maize incurs some loss of nutrients. Particular significance was given here to the production of organic acids and the degradation of plant protein to non-protein nitrogen. Since there is a general shortage of proteins, which will be converted more and more to human food, the use of NPN in the feeding of ruminants is carried out in
487 many places, but, as it was stated, the extent to which supplementary NPN can be used with maize silage is limited by low levels of energy intake and a relatively high content of NPN in the silage. We mentioned some of the problems emphasised and solved in the research work already finished, but we hope that the discussion will open new questions, which will probably show that more research is needed to achieve higher efficiency in using the maize crop as a feed for fattening cattle.
W. Kaufmann
I would ask Dr. Wilkinson if he has any idea what is the reason for the reduction of intake if you use lactic or acetic acids as a supplement?
J.M. Wilkinson UK
That is a good question! We looked at acid/base balance because we felt that maybe the acid load on the animal was too great and that we were inducing acidosis. In one experiment, the first experiment, we actually added alkali and were able to show an increase in blood pH from slightly below normal to slightly above normal. In the experiment where we added acids we were not able to show any change in rumen pH or blood pH but there was a tendency for blood CO- level to decrease. So the animal may have been compensating for the increased intake of acid by increased respiration of CO, to maintain blood pH at the normal level. There is quite a lot of evidence'from America and elsewhere, where feedlot cattle are given very high levels of grain, of a low rumen pH and acidosis - lactic acidosis, but the first symptom of this is complete reduction in intake - the animal stops eating altogether. So it is possible, 'though we are not sure, that with maize silage there may be some subclinical level of acidosis that is limiting the amount that the animal eats.
W. Kaufmann
Might it be that there is a reduced flow of saliva because
488
of the lack of physical structure?
J.M. Wilkinson
Well, one would expect this to be greater with grain than with silage.
W. Kaufmann
Quite. But there might be a reduction of saliva flow and if you would use a ration of maize silage and one or two kg of hay, perhaps you should try it ... did you try?
J.M. Wilkinson
No, but I don't think it would do much good; I think there is sufficient fibre in the maize silage, as we feed it, as the sole component of the diet apart from mineral supplementation. I think there is sufficient fibre to maintain saliva production. Whether the concentration of bicarbonate in saliva is maintained, I don't know.
Refsgaard Andersen Dervnark
In connection with the last topic, lactic acid, we have no experience with maize silage but in our clover/grass silage we have seen when lactic acids were increased by the climate, for instance, from 5 - 6% in the DM to double that amount, we have a decrease in feed intake of between 10% and 30%.
It has also been mentioned that organic acids have an influence on feed intake. In other experiments we are using formic acid additives and we have seen an increase in intake. Also, using propionic acid, for instance, on fresh material we have improved intake. How would you explain these two different ways of influencing feed intake?
J.M. Wilkinson
The level of formic acid normally added to silage is much
489 less than the acid level present in extensively fermented grass silage. Wilkins has infused formic acid and lactic acid into the rumen of sheep and found very considerable reductions in intake and he equalised the hydrogen ion input from the two acids. So it could be simply a question of levels.
W. Kaufmann
But there is normally a change in digestibility between green food and silage, because there is a loss of carbohydrates which are fermented and an increase of crude fibre, which normally reduces digestibility. Did you measure these differences in digestibility which would have influenced intake too?
J.M. Wilkinson
There was very little difference in digestibility between the unensiled, which was frozen material, and the ensiled material. It could be that freezing itself depressed the digestibility rate but it is impossible to compare, over a long period of time, fresh and ensiled material because if you cut and feed each day the material is changing. We harvested and froze a complete batch and ensiled a complete batch, simultaneously.
E. Zimmer West Germany
My question is in another direction and refers to Dr. Boucqué and Dr. Geay. They stated the inferior utilisation of pelleted maize and it seems to me a question of sub-optimal physical structure. Is this your explanation or is it influenced too by, maybe, over-drying and factors which can affect the low utilisation? An additional question. Did you do any research using not pellets but brickettes with a better physical structure?
Ch. V. Boucqué Belgium
We did not compare cobs or wafers with pellets of maize but an explanation can be given by the possible effects of particle size in the digestive tract. It is not only the case for
490
dehydration and pelleting of maize, but we also observed the same effect after grinding hay of the same quality and the same harvest and pelleting after grinding. Digestibility decreased and intake increased and the net output per kg DM also decreased after grinding and pelleting. I think it is just a question of the rate of passage.
E. Zimmer
But is the reason the particle size of the material?
Y. Geay France
I would agree with Dr. Boucqué. We have compared different processing forms, wafers, cobs and pellets, and the speed of intake increased with the decreasing of the size of particles. When we have given the. pellets at the same quantity of intake as silage, feed efficiency was about the same. I think it is due to increase of speed of flow.
R.J. Wilkins UK
Can I take up one of the points in Professor Giardini's first paper in which he was making comparisons between maize made into silage and early, medium and late cuts. He found in his results with beef cattle, an extremely interesting interaction between the stage of growth and energy supplementation. As I understood it, when materials were fed without energy supplementation the growth rates were highest with the late cut materials, whereas the situation was reversed when concentrate supplements were added. I would like to hear Professor Giardini's ideas on the reasons for this. Is it because of the high starch in maize silage plus the high starch in the supplement causing a depression in digestion rate of the fibre in the rumen, or was there merely an acidosis situation? .
S. Bacvanski 'Iugoslavia
In our experiments with high concentrate rations we used
491 nitrogen or sodium bicarbonate as a buffer and we found that consumption of food was higher and liveweight gain lower; feed conversion ratio was higher per kg of liveweight gain, but, in doing experiments when you put in both fishmeal and sodium bicarbonate you have the best liveweight gain.
T. Cobic
It's a question of buffer. In their experience with buffers they got worse conversion and a higher intake of concentrates and so on, but you got better results using buffers with silage.
J.M. Wilkinson
It seems as if the improvement in intake by adding ammonia to buffer the silage did not do any good as far as utilisation was concerned and I indicated that when we added different levels of ammonia to increase silage pH, nitrogen retention was not improved, in fact, it was reduced. Now, we added sodium bicarbonate to diets which contained fishmeal and there was very little effect because of the dominating effect of fishmeal on the performance of the cattle. There was a slight increase in intake and a slight increase in growth rate and a slight improvement in feed efficiency, I am surprised that performance was reduced in your experiments because, looking at the effects of sodium bicarbonate on protein synthesis in the rumen, by increasing the rate of turnover of material through the rumen, it is possible to increase microbial protein synthesis. So one would expect that when buffering a diet consisting largely of grain, one would have two benefits - a reduced possibility of lactic acidosis and increased rate of turnover of material through the rumen. These two effects would give you an increase of intake and an increase in protein supply to the animal. So, I am surprised. I am not sure of the explanation of your reduced performance. Have you any explanation for it?
Refsgaard Andersen
Could it be the level of protein? You are working on a very
492
low level of protein.
J.M. Wilkinson
No, we work on a very high level of protein, 15% of the DM, with fishmeal comprising something like 35% of the protein.
T. Cobic
There is a lot of evidence from American workers who are using quite a lot of these buffers in order to counter lactic acidosis and in the majority of papers the results were just the same - with high concentrates, increasing intake and decreasing liveweight gain. So it's not easy to explain. It seems that with high concentrate rations there is quite a reduction of saliva flow. Bicarbonate ought to be beneficial but apparently it is not.
J.M. Wilkinson
One possible explanation may be that the increase in intake of a high concentrate diet may possibly reduce digestibility. Secondly, if you increase intake you increase VFA production in the rumen, so that you really need the buffer there if the animal is producing more acids in the rumen.
W. Kaufmann
Yes, but there is at the same time a higher efficiency of utilisation of metabolisable energy. There is a reduction in digestibility but utilisation of metabolisable energy increases.
I can give you some figures which are the latest results of colleagues working with ground maize. They found a reduction in digestibility and an increase in the utilisation of metabolisable energy of about 11%. Giving a summary of the loss in digestibility and the increase of utilisation, it was, for net energy, no change. The only change was in intake, which might be of importance for fattening bulls but not for cows, because you cannot change to ground maize in such amounts of the ration
493
with cows as you can do for fattening bulls.
D. Lanari Italy (Answering Dr. Wilkins ' earlier question to Professor Giardini)
According to Giardini, when you use a riper maize you have got more grain in the maize silage so that there is less advantage in adding ground grain.
J.M. Wilkinson
Can I add to that? We compared the value of maize silage fed to young calves at 70% of the daily DM intake with barley and dried grass as a supplement. We harvested material at 20, 29 or 38% DM and we found that there was a small increase in intake from the silage, a decrease in digestibility of dry matter, organic matter and of cell wall material but an increase in live-weight gain and in efficiency of feed conversion. We explain this on the basis of more starch, more digestible organic matter, coming from the cell content rather than cell wall material, as the dry matter content increases and possibly a change in VFA proportions associated with the starch.
P. O o s t e n d o r p The Netherlands
May I change the subject to the addition of NPN to silage? There seems to be a contradiction between the results from Belgium and Italy with the addition of NPN, and those presented by Dr. Lelong from France. He found a reduction in growth rate of about 10% whereas other results he presented were more or less at the same level. Can further details be given on the background to explain the difference between these results?
A second question is for Professor Giardini on the practical side of application of the different products. How has this been developed up to now in Italy? In your paper you state that there are still a lot of problems to be solved. Is this already in practice or is it still in an experimental stage?
A third question, of a more general nature, is whether there is experience on the addition at ensiling of other products such as soyabean meal?
494
A. Giardini Italy
In Italy we have only experimented up to now in the use of these silage additives. On my farm, for the past year, I have used these products, based on urea, on 1 500 ha and I am very satisfied. I don't know about adding soyabean meal to the silage.
Geay
When we consider the different experiments which have been made with young bulls in which we have compared the daily gain and feed efficiency of animals which received protein cake or urea at the same level of crude protein, we have always found a decrease of about 10% of daily gain with animals which received urea. We have not measured the quantity of digestible protein which arrived in the intestine but when we made an estimate of the quantity of digestible protein which arrived in the intestine we could explain exactly the difference in daily gains, and the difference in meeting the requirements of the animals.
D. Oostendorp
Dr. Geay, may I ask about these supplements which you are talking about? Is this an addition of urea to the concentrates or is it an addition of urea to the silage?
Y. Geay
The mixture between urea and maize is in bulk, not in the silo, but at the time of feeding.
D. Oostendorp
Perhaps that is the explanation for differences in results because if you are adding urea at the time of ensiling, it must influence the ensilage process and can perhaps make a difference in utilisation in the rumen.
495
W. Kaufmann
So, you should measure, before feeding, the amount of NPN which is fed either directly or in the silage. Furthermore, you should measure the true digestible protein content in the maize silage. There may be big differences between the calculated figure of 13, 15, 10 or 11% of digestible protein, and the real figure of only 6 or 5.
R.J. Wilkins
Some hesitation was expressed in one of the papers earlier about the way in which we added urea to the silo with rather mature maize silage. This is something upon which we have some experimental information in that we have taken maize which, for British conditions, was extremely mature with a DM content of 42% and only 3.7% of water-soluble carbohydrates - this was after frost. To this silage we added urea at four different rates, between 0.5% of the DM and 2.0% of the DM. There were some rather odd features in the results that we obtained in that there was no butyric acid formed in any of the silages although some of them had rather high final pH values. Where we were adding no urea we produced silage with a pH of 4.4; at 0.5% urea, 4.6; 1% urea, 5.0; 2% urea, 5.5. We were really going up to those high rates to establish what sort of response we obtained. The particularly odd feature here was that there was no significant difference in acetic acid content between any of these silages and no butyric acid present. Our rather hesitant conclusion from this experiment was that even with the very low-sugar maizes we would get good preservation with the addition of urea to the silo. I say this was a hesitant conclusion because it was work done on a fairly small scale and with one particular crop. In the case of material harvested at an earlier stage of growth we could go up to about 2% of urea on a DM basis added at ensiling, and still produce silage with pH values of below 4.2.
W. Kaufmann
We are coming back to NPN. Let me make a remark. In
496
designing experiments on this subject, one should take into consideration the requirements of digestible protein of the animals, and every time one should use three groups; one group with a supply of protein sufficient to meet requirements (as we believe) the second group with a reduced supply of food protein being replaced by NPN, and the third group using the low level of protein without NPN. Very often we find that the lower protein levels cover the requirements because we do not know enough about this. One should draw up these treatments after looking at the different results in the literature.
Ch. V. Boucque
I have not so much to add to what I said before but to answer Dr. Oostendorp's question perhaps I can explain a little more about the set-up.
First of all the circumstances were present for good utilisation of NPN sources. We were below the total crude protein content, on a DM basis set by Satter and Roffler - roughly, 13% - so the conditions for utilisation were present. Then they had this conference which proves, that, for the entire period, 10% crude protein on a DM basis is about sufficient for 1 kg daily gain but is not enough when we want a higher daily gain. The circumstances at the beginning of the experiments were such that the concentrates for all the groups were isocaloric, so on this point there was no problem. At the beginning we fed the four groups, the negative, the positive, the Prosil-treated silage and the urea-treated silage, starting with only 5 kg per animal per day on the first day. After two days we increased this quantity gradually to reach after only three weeks, an ad libitum intake, but these circumstances were equal for the four groups. With these methods and isocaloric rations, we observed a utilisation of the NPN source and no decrease in daily gain.
Regarding the quality of the maize, it was in the dough/dent stage. We had 26% DM but in our climate this corresponds with a good dough/dent stage of the maize. So we did not find the negative effects observed by our French colleagues. Urea was put in the silo at the time of ensiling and was very well distributed in the silage.
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Perhaps I could put a question to Dr. Lelong and Dr. Geay -when the urea was added at the time of feeding, was it once a day or was it spread over the entire quantity of feed?
C. Lelong France
It was mixed with the entire quantity of feed and feeding was twice daily. However, it is possible to find one or two trials in our 50 trials in which the performance of cattle was equal with urea and with protein cakes, but when we repeat these trials in many varied conditions, with many breeds, many DM levels and so on, we have, on average, a decrease of 10%. Have you many repeats of these trials?
Ch. V. Boucque"
Yes, it is going on now - we are repeating it for the third time. Again this year, for each treatment we have two groups of 700 to 800. In experiments based on dried sugar beet pulp we found different results. When we fed the urea only once a day in a small amount of concentrate, we did not get the same response as when we mixed urea in the dried beet pulp. When you feed twice a day maybe you reach values above 5 to 6 mg NH~ per 100 ml rumen fluid which I think Satter mentioned. When you get above this level there is no possibility of using the ammonia and this can happen whether you feed once or twice a day, but, when you feed ad libitum, all day and all night, this level of ammonia in the rumen is more stable and may be better used.
Y. Geay
I think there is no contradiction exactly - it depends on the different utilisation of urea and the proportion of nonprotein nitrogen and carbohydrates.
W. Kaufmann
There are only five minutes more for discussion and I think
498
perhaps there are some questions to the papers of Beever and Van Es, or are there questions to other papers?
Ch. V. Boucque"
During the coffee break I was talking to Dr. Wilkinson about his high levels of nitrogen added to the silage and he thinks that 17% crude protein is needed, so there we are at a level 4% units above the maximum of 13% mentioned by Satter and he also mentioned that 13% is the maximum level when the digestibility of the energy is very high, but the level of 13% diminishes when the level of the digestibility of the energy decreases. So, in silage we are not at a maximum digestibility of the energy. So I think that to be utilised, for maize silage only, 13% is too high for crude protein on a DM basis. Maybe it's only 11% because the digestibility of the energy is lower.
J.M. Wilkinson
There are two things here. There is the concentration and the rate of consumption. With young calves given maize silage as the sole source of energy, the level of intake is low. If you look at Table 5 in my paper, you will see a situation where, with 15% crude protein we achieved nearly 1 kg/day growth rate from these young calves because intake was high in terms of supplementary energy. So protein requirement must be defined ultimately, as Dr. Kaufmann says, as the digestible true protein supplied to the animal in relation to the quantity of energy absorbed. So it's a quantitative figure - it must be g per day, or per kg bodyweight, which takes into account the difference in intake between maize silage alone and maize silage with supplementary protein. With higher energy concentration, I agree, one should use a lower concentration of protein but with a low intake I think it is necessary to have a higher level of protein.
R.L. Vetter United States of America
I would like to comment on silage dry matter intake.
499 Dr. Kaufmann has elucidated the many factors affecting the interaction and the basic principle is net energy available for production. The intake problem is very apparent in the US in our silage programmes with the young animal. I think as we go into larger sizes we get a diminution of the intake relationship. However, if you calculate, for instance, for a 200 kg calf consuming 5 kg DM, it is, in fact, taking in 15 kg of water with that silage. We do not have definitive data on this, it is just an observation, but with that volume of water intake and the calf's restricted ability to consume feed as a result of gut limitations, it may also still desire more water consumption because of the acidic nature and the electrolyte balance of the rumen. There is some indication that there is, relatively speaking, a higher water intake and it is just a basic fill factor of water relationships that the animal exposes itself to in this type of diet. There is some indication, for instance, of the animal wanting to consume more salt. Naturally, if it has salt available, free choice, there is a buffering aspect, bringing in more water, so this water relationship is very important.
C. Lelong
I wish to make a general observation. This morning we heard about measurements of digestibility of energy or protein but it is difficult to predict with these measurements the real performance of animals which are fattened because you do not speak of the interaction between these measures and the breed of the animals. For instance, when you feed early maturing breeds such as Friesian, if any factors such as source of protein, digestibility of energy, or other factors, reduce the efficiency use of energy, it probably has no effect on the growth rate of such animals. On the contrary, with late maturing breeds of high performance such as the Charoláis and Italian breeds and perhaps others, a reduction in efficiency after absorption from the intestine has an effect on the animal's performance.
W. Kaufmann
We think there is no difference in principle in rumen
soo fermentation and in the intestine; there is only a difference in the efficiency of metabolism.
C. Lelong
There are only limited data available on this.
W. Kaufmann
I have some questions on the paper by Beever. First, there was no difference found between pellets and ground maize in the proportion of C_ to C- in the rumen. Perhaps this depends on the time of measurement. There might be a difference, 1, 2, 3 or 4 hours after feeding. Was it measured each'hour?
J.M. Wilkinson
No.
W. Kaufmann
This measurement should be made because it might explain the differences in the literature. I know most of those who have fed ground cereals or maize found a higher proportion of propionic acid and that might be either from feeding frequency or from time of measurement in the rumen.
There is a second question. Which is the more important factor accounting for the higher protein in the intestine using flaked maize, the higher organic matter digested or the protected protein?
J.M. Wilkinson
Well, probably the value to the animal is the ratio of absorbed protein to absorbed energy which is more favourable from flaked maize than from ground maize.
SOI
W. Kaufmann
There is a third question. Normally we have calculated bacterial protein synthesis on the basis of organic matter digested and not on ATP because ATP is not quite correct, it seems to us, since there might be anaerobic and aerobic processes in the rumen, so one can make mistakes, perhaps.
R.J. Wilkins
Could I direct a question to Dr. Kaufmann? You were suggesting that in diets in general about 70% of the protein would be degraded in the rumen. Do you have any information on maize silage in relation to the degree of breakdown?
W. Kaufmann
Yes, not on pure maize silage but there were rations in which maize silage was a component, and there were no differences in degradation rates, but to be quite correct, I told you 70% as an average. There are results where the degradation is between 60%, 65% and 80% but most of the results are in the region of 70%. I mentioned it only to give information on NPN.
R.J. Wilkins
With grass silage fed at fairly low levels we find a higher figure than 70.
W. Kaufmann
Sometimes, yes. If there are no further questions we will close the dxs-
cussion.
503
SESSION V
SYSTEMS OF PRODUCTION AND EFFICIENCY OF USE OF RESOURCES
Comparative aspects of systems of beef production from different forms of the maize crop,- interaction with age, breed and sex of animal; efficiency of use of resources of land, labour and energy, including economic aspects.
a) Systems of bull-beef production from, the maize crop b) Feedlot beef production and systems of production from beef cows
and their calves.
Chairman: D. Lanari
Animal Feed Science and Technology, 1 (1976) 505-512 505 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
EFFECT OF WEIGHT AT SLAUGHTER ON THE EFFICIENCY OF FATTENING YOUNG CATTLE
T. COBIC Livestock Research Institute, Novi Sad, Yugoslavia
ABFTRACT Thirty Simmental intact male calves divided into three
slaughter weight groups (380, 420 and 460 kg) were used in order to study the effects of final weight on live weight gain (LWG), feed conversion and yield of carcass. The animals were fed on a high concentrate mixture based on ground maize 65% and on limited amounts of silage (up to 3 kg daily)· The highest average LWG (1368 g) was achieved in animals slaughtered at the body weight of 436 kg, and it differed significantly (P<0.01) from those slaughtered at higher (1207 g) or lower (1213 g) weights.
Dressing percentage was affected by the various treatments, increasing with final body weight to give 57.1, 59.2 and 59.8% for the respective treatments. The difference between the first and the other two treatments was highly significant (P<0.01)
Daily intake of concentrates, SE and CP was higher in animals finished at 436 kg body weight than in those at 460 kg respectively by 3.4, 7.2 and 6.8% and in relation to animals slaughtered at 379 kg by 7.9, 2.9 and 11.6% respectively. This was probably related to the high gains of animals on treatment 2. The high consumption of nutrients by the bulls on treatment 2 resulted in higher gains and more efficient conversion of feeds and nutrients than by those on treatment 3. The increase in conversion of concentrate mixture amounted to 6.1%,-of maize silage, 12.6%;of SE, 5.8% and of CP, 6.2%, while there were almost no differences between treatments 2 and 1.
INTRODUCTION
According to former experiments (Huth, 1966; Krüger and Mayer, 1967; Krüger et al., 1967; Ille's, 1970; Obracevic et al., 1972 ab) the live weight gain (LWG) in fattening young bulls depends on age and intensity of feeding. In most cases the average daily gain increases up to 8-10 months of age, then shows
506
a tendency to decrease. Conversion of starch equivalents (SE) per kg of LWG increases slowly up to ten months of age .or about 300 kg, increasing more rapidly thereafter up to slaughter weight. This is a logical consequence of the formation of different tissues in the body, most fat being formed at the end of the fattening period, and it is well known that fat deposition requires the highest amount of energy. However, there is some other evidence that gains were higher after 8 months of age (Luitingh, 1963), or after 400 kg of body weight (Levy et al., 1975), while Nichols et al. (1964) and Liebenberg et al. (1973), found practically no differences in gains of bulls fattened to different slaughter weights. The majority of these investigations were carried out using Black and White cattle. This study deals with the effect of different slaughter weights of Simmental bulls on live weight gains, conversion of feeds and nutrients, and dressing percentage.
MATERIAL AND METHODS
Treatments Three groups of animals were formed in order to study the
effect of slaughter weights of 380, 420 and 460 kg respectively, on fattening performance of bulls fed on the same diet. Animals
Thirty commercial Simmental intact male calves of unknown age were allotted at random into three groups weighing 220 kg on average. Before starting the experiment they were housed in the same barn for a month and fed on the same mixture. Feeds and feeding
The concentrate was a mixture consisting of 67% ground maize, 5% wheat bran, 15% sunflower oil meal, 5% guar meal, 5% dry sugar beet pulp, 1% calcium carbonate, 1% salt and 1% premix, with SE 67.1, digestible crude protein (DCP) 11.95%, dry matter (DM) 88.95% and crude fibre 6.64%. It was given twice a day, beginning with an amount of 5 kg and gradually increasing thereafter.
Maize silage was given at a quantity of 3 kg per animal per day. The animals were tied, but group fed and watered twice a day.
507 Weighing and slaughter technique
At the beginning of the experiment the young bulls were weighed individually, then at intervals of three months and finally at the end of the trial. They were slaughtered at an average body weight of 379, 436 or 460 kg, and the dressing percentage was determined on a hot carcass weight basis. Analysis of data
Analyses of variance (Steel and Torrie, 1960) were carried out on rate of gain in live weight and on dressing percentage. Results and discussion
Initial and final body weights as well as live weight gains obtained in the experiment are shown in Table 1.
TABLE 1 EFFECT OF DIFFERENT TREATMENTS ON DAILY LIVE WEIGHT GAIN AND DRESSING PERCENTAGE
Treatments
Planned slaughter weight (kg) Number of animals Average initial weight (kg) Average final weight (kg) Total live weight gain (kg) Days on experiment Daily gains (g) Differences (g) 460 420
Dressing percentage Differences 460 420
1
380 10 221.4 379.1 157.7 130 1213
6 145** 57.1
2.7** 2.1**
2
420 10 222.6 436.1 213.5 156 1368
161** -59.2
0.6
3
460 10 221.3 460.3 239.0 198 1207
--59.8
-
SE of diff.
52
0.52
►* = Ρ <0.01
Initial weights of animals were almost equal, the biggest difference between groups being only 1.3 kg. Therefore it may be assumed that the initial weight did not affect the live weight gains.
Animals of treatments 1 and 3 were slaughtered at the planned
508 weights, while those of treatment 2 were slaughtered at a live weight which was higher by 16.1 kg as a result of higher gains than expected in the last period of fattening.
The highest average daily gain, 1368 g, was achieved in animals on treatment 2, fattened up to a body weight of 436.1 kg, while those on treatments 1 and 3 gained on average 1213 and 1207 g respectively. Differences of 155 and 161 g, or 12.8 and 13.3%, between treatments 1 and 3 and that on treatment 2 were highly significant (P<0.01), while that between treatments 1 and 3 was not significant.
The results of this study indicate that animals slaughtered at 460 kg had lower daily gains than those slaughtered at 436 or 379 kg body weight. Using a similar ration, based on ground maize Obracevic et al., (1972 a,b) found a similar tendency when comparing live weight gains in different periods of fattening (150 - 250, 250 - 350 and 350 - 450 kg) where the average live weight gains were respectively 1215, 1278 and 1256 g in the first and 1265, 1404 and 1182 g in the second experiment. Huth (1966) concluded that, irrespective of average daily gains, all animals reached their highest gains between 280 and 364 days, i.e. at a younger age, which corresponds with our data. Illés (1970) presented results on Simmental fattening bulls slaughtered at 285 and 457 kg and obtained live-weight gains of 1190 and 1070 g respectively. On the other hand, several authors found practically no decline in daily gain as a result of increasing slaughter weights of fattening animals within the range of 375 -454 kg (Nichols et al., 1964; Levy et al., 1968, 1975).
Dressing percentage was affected by the various treatments. It is obvious that the degree of fatness influenced dressing percentage since it gradually increased by increasing the body weights. The difference between treatment 1 and the other two is considerable and highly significant, while that between treatments 3 and 2 was not significant. The results of this experiment correspond with findings of other authors, comparing different slaughter weights.of fattening animals (Luitingh, 1963; Nichols et al., 1964; Levy et al., 1968; Illés, 1970; Sperling et al., 1974; Levy et al., 1975).
It seems that this question needs some further studies, especially with respect to type of ration and breed involved.
509
Feed and nutrient intake and conversion ratios are presented in Table 2.
TABLE 2 FEED INTAKE AND CONVERSION RATIOS
Treatments
Slaughter weights (kg) Daily concentrate intake (kg)
Maize silage (kg) SE (kg) CP (g) Dry matter (kg) Dry matter (% of bodyweight) Crude fibre (g)
Conversion ratio, /kg LWG
Concentrate mixture (kg) Maize silage (kg) SE (kg) CP (g)
1
379.1 6.82
2.57 4.783
865 6.57 2.19
563
5.62 2.12 3.943
713
2
436.1 7.36
2.94 5.398
965 7.38 2.24
512
5.56 2.15 3.944
705
3
460.3 7.12
2.92 5.037
904 7.00 2.06
464
5.90 2.42 4.172
749
The highest average daily intake of concentrates was by the animals on treatment 2 (7.36 kg) and the lowest in those on treatment 1 (6.82 kg). Consumption of concentrate mixture on treatment 2 was higher by 7.92% and 4.40% respectively than on treatments 3 and 1. Daily consumption of silage was almost equal on treatments 2 and 3, while on treatment 1 it was lower by about 12%. However, dry matter intake was the highest on treatment 2 also, the difference in relation to treatments 3 and 1 being respectively 12.3% and 6.5%.
The high consumption of concentrate mixture on treatment 2 caused higher gains and more efficient conversion of feeds and nutrients than those on treatment 3, but between treatments 2 and 1 there were almost no differences in conversion of concentrates, maize silage, SE and CP.
Presumably more net energy was available to animals on treatment 2 which resulted in higher gains and almost the same level of conversion of concentrates, maize silage, SE and CP as
510 on treatment 1, while the consumption of feeds and nutrients per kg of LWG was higher in animals slaughtered at 460 kg body weight by 6.1% of concentrates, 12.6% of maize silage, 5.8% of SE and 6.2% of CP.
Obracevic et al. (1972), in an experiment with young bulls fed on high concentrate rations based on 63 - 70% of ground maize, found an increase of 24.7% of daily feed intake between 250 - 350 kg and 350 - 450 kg of body weight, while dry matter intake increased by 27%. At the same time conversion of feed, feed units and CP per kg of LWG increased by 27, 30.5 and 14.7% respectively. Using 80% of concentrates in a ration based on 69 - 72% ground maize, Obracevic et al. (1972 a,b) reported also an increase of average consumption and conversion of feeds and nutrients, as the weight of animals increased. Average daily feed intake between 250 - 350 kg and 350 - 450 kg body weight increased by 6.9%, while the consumption of dry matter increased by 5.6%. Conversion of feed and feed units per kg of LWG increased by 26.8 and 28.8% respectively: Studying conversion of SE in Simmental bulls, Bacvanski et al. (1964) found a gradual increase in SE needed per kg of live weight gain. At the weights of 225 - 255 kg it amounted to 3475, and from 385 - 415 kg conversion was 4903. Efficiency was gradually declining with body weight but with the ration used was largely based on roughages.
The results of this study with respect to conversion of energy are in agreement with those of many authors (Luitingh, 1963; Nichols et al., 1964; Taylor et al., 1966; Levy et al., 1968; Huth, 1970; liles, 1970). Liebenberg (1973) reported a very negative correlation between live weight gain and consumption of food in fattening animals (r = -0.929*** to r = -0.985). However, Levy et al. (1975) found practically no difference in conversion of ME into live-weight gain in young fattening bulls up to 400 - 500 kg body weight on high concentrate rations.
Therefore, further research is needed to investigate this problem as regard final body weight and its efficiency with respect to use of feed, body composition and economy of gain, using different concentrate to roughage ratios in a maize based diet.
Sil
REFERENCES
Bucvanski, S., Stojanovic, Ν., Vucetic, Sofija and âobic, T., 1964. Invest
igations of the value of alfalfa hay and silage in feeding and fattening bulls. Journal for Scientific Agricultural Research, XVII, 56
Huth, F.W., 1966. Typfragen und Mastmethoden beim Rind. Zeitschrift für Tierzuchtung und Zuchtungsbiologie, 82, 2.
Iluth, F.W., 1970. Zur Frage der Nährstoffversorgung und Gewichtsentwicklung bei der Jungbullenmast. Der Tierzüchter, 22, 6.
Illés, Α., 1970. Technology of fattening from birth to different live weights. Ällattenyésztés, 19, 3.
Kruger, L., and Meyer, F., 1967. Untersuchungen zur Frage der Erzeugung und der Wertbestimmung von Rindfleisch. Zeitschrift für Tierzuchtung und Zuchtengsbiologie, 83, 2.
Krüger·, L. , Meyer, F. and Wassmuth, R., 1967. Untersuchungen zur Frage der Erzeugung und der Wertbestimmung von Rindfleisch. Zeitschrift für Tierzuchtung und Züchtungsbioiogie, 83, 3.
Levy, D., Holzer, Ζ. and Volcani, R., 1968. The effect of age and live weight on feed conversion and yield of saleable meat of intact Israeli Friesian male calves. Animal Production, 10, 3.
Levy, D., Hölzer, Ζ. and Folman, Y., 1975. Effect of concentrate: roughage ratio on the production of beef from Israeli Friesian Bulls slaughtered at different live weights. Animal Production, 20, 2.
Luitingh, H.C., 1963. The efficiency of beef production in terms of carcass weight increase as influenced by the ration concentration and the age of steers. The Journal of Agricultural Science, 61, 1.
Nichols, J.R., Ziegler, J.H., White, J.M., Kesler, E.M., and Watkins, J.L., 1964. Production and carcass characteristics of HolsteinFriesian bulls and steers slaughtered at 800 or 1,000 pounds. Journal of Dairy Science, 47, 2.
Liebenberg, O., Sperling, G. and Beckert, H.G., 1973. Fattening performance and carcass value of young bulls of German Friesian (DSR) cattle fattened on farm produced fodder for high final live weight. Archiv fur Tierzucht, 16, 6.
Obracevic, S., Bacvanski, S., Cobic, T., and Vucetic, Sofija, 1972a. The effect of reduced protein amount in rations during the intensive fattening of young bulls. Journal for Scientific Agricultural Research, XXV, 89.
512
Obracevic, C., Bacvanski. S., ïobic, T. and Vucetic, Sofija, 1972b. Feed conversions with varying ratios of concentrates to alfalfa meal in fattening young bulls. Journal for Scientific Agricultural Research/ XXV, 92.
Steel, R.G.D. and Torrie, J.H., 1960. Principles and Procedures of Statistics. McGraw-Hill Inc., New York.
Sperling, G. , Beckert, H.G., Liebenberg, o., 1974. Fattening performance and carcass value of young bulls of German Friesian (DSR) cattle fattened on farm-produced fodder for high final live weights. 2nd Communication. Archiv für Tierzucht, 17, 1.
Taylor, St. C S . and Young, G.B., 1966. Variation in growth and efficiency in twin cattle with live weight and food intake controlled. The Journal of Agricultural Science, 66, 1.
Animal Feed Science and Technology. 1 (1976) 513-519 513 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
ECONOMIC ASPECTS OF HIGH-PLANE FEEDING OF BULLS WITH MAIZE SILAGE
K. WALTER Lehrstuhl für Wirtschaftslehre des Landbaues der Technischen Universität München in Weihenstephan, GFR.
In the Federal Republic of Germany about 50% of beef is produced from fattening bulls, for which the most important fodder is maize silage. About 50% of the bulls produced are being fattened with this type of fodder, and a high feeding level is a most important part of this procedure. As a result of differences in breed of animals, the quality of maize silage and the individual farm situation, length of the period of production and final live weight vary within a considerable range. In some parts of the Federal Republic a pasturing period is being integrated into the fattening period, whereby the animals are finished indoors afterwards from about 320 to 600 kg live weight. Fattening of bulls with concentrates is of no importance because of the relatively high price of concentrates.
Calves needed for fattening are supplied almost exclusively by dairy herds. For this reason beef production is carried out practically only with animals of the German dual purpose breeds, and pure beef breeds are of little importance.
In general fattening farms buy the calves at a weight of about 70 - 80 kg (South German conditions) and 45 - 50 kg (North German conditions) respectively. The calves are then reared by the method of "early weaning" up to a live weight of 100 -110 kg. In recent years there has been a marked trend to greater division of labour regarding the size of the herds. Specialised farms carry out rearing and sell the calves at a weight of some 150 kg to the fattening farms. The latter do not need any sheds or labour for rearing and are, therefore, in a position to fatten a larger number of bulls. Owing to the increasing importance of this division of labour, the following calculations are based on the purchase of calves at a weight of 150 kg.
Owing to the great importance of high-plane fattening of bulls with maize silage the author is focusing on the economic aspects of this procedure. Primarily the effects will be stressed of the quality of maize silage and the input of concentrates on the economics of high-plane feeding.
514 In Table 1, the data related to four different procedures
of high-plane feeding are shown. As the questions .of optimal final live weight are not being discussed here, a common weight range of 150 - 550 kg is assumed for all. For maize silage with 30% dry matter content and 1.5 kg soya bean meal for protein (Procedure I), an average consumption of dry matter for the whole fattening period of 5.6 kg per day from maize silage is assumed. On a starch equivalent content for the maize silage of 600 starch units per kg of dry matter this feed ration results in daily gains of 1100 g, on average, over the whole period of fattening. The total period of fattening amounts to 364 days with a total starch unit requirement of roughly 1600 kSE.
If we feed additionally 1 kg grain per day (Procedure II), the daily consumption of dry matter increases, 'while the dry matter intake from maize silage decreases. Altogether the result is an increase in daily consumption of starch units and consequently an increase of the daily gains up to 1300 g. The period of fattening is reduced to 308 days. Owing to the reduced period of fattening, maintenance requirement decreases and the total demand for starch units decreases to 1480 kSE. On a net yield of 6000 kSE 4.9 bulls can be fattened per ha of maize with Procedure I and 6.4 bulls with Procedure II, respectively.
If maize silage of only 25% dry matter (dm)* content is being fed, the dry matter consumption from maize silage is reduced tremendously. Experiments have shown that for each reduction of 1% of dry matter, the consumption of dry matter from maize silage decreases at an average rate of about 0.15 kg per day. Consequently at 25% dm content, only 4.85 kg of dry matter from maize silage is taken in. At an equal concentration of nutrients per kg dry matter as with maize silage of 30% the intake of nutrients from maize silage and the additional 1.5 kg of soya bean meal (Procedure la), only yields an average daily gain of 866 g. The period of fattening amounts to 462 days and the total nutrient requirement is 1833 kSE. If there is a need to achieve daily gains of 1100 g with this type of maize silage a supplementary feed of 1.15 kg of grain per day is necessary (Procedure IIa) . Assuming the same net yield of 6000 kSE/ha as with maize silage with 30% dry matter content per ha of maize silage, with 25% only 4.5 and 6.5 bulls respectively could be fattened with Procedures la and IIa. * dm = dry matter; DM = Deutsch marks
TABLE 1 DEVELOPMENT OF LIVE WEIGHT AND FEED CONSUMPTION PER BULL IN FOUR SELECTED PROCEDURES OF HIGH-PLANE FEEDING WITH MAIZE SILAGE
Item
Weight stage from ... to Average daily dm intake from maize silage * Soya bean meal** Grain*** Minerals Average starch-equivalent intake per day Total starch-equivalent intake Average daily gains Length of production period TOTAL FEED CONSUMPTION Maize silage Soya bean meal Grain Minerals
kg
kg kg/day kg/day kg/day
SE/day
kSE g/day days
t dm t t t
Maize silage, 30% dm
Procedure I
5.6 1.5 -0.1
4417
1608 1100 364
2.04 0.546 -0.036
Procedure II
150
5.06 1.5 1.0 0.1
4813
1482 1300 308
1.56 0.462 0.308 0.031
Maize silage, 25% dm
Procedure la
550
4.85 1.5 -0.1
3967
1833 866 462
2.24 0.693 -0.047
Procedure IIa
4.23 1.5 1.15 0.1
4422
1609 11O0 364
1.54 0.546 0.419 0.036
600 SE per kg of dry matter ** 705 SE/kg *** 720 SE/kg
516 In Table 2 the proportional outputs and costs as well as
the gross margins of the four systems of fattening are compared without taking into consideration labour and buildings (i.e. assuming a family farm with existing buildings). These calculations are based on the present price-cost ratios in the Federal Republic. An examination of the feed costs reveals that costs increase with increasing use of concentrates despite the reduction of the fattening period and the consequent decrease of the starch unit requirement.
There is a particularly clear influence of the dry matter content of the maize silage on feed costs. While with Procedure I the feed costs amount to 604DM*/bull, with Procedure IIa at the same daily gains they rise to 767DM/bull as a result of the higher need for concentrates. Owing to the reduction in other costs as a result of the reduced fattening period the gross margin per bull does not decrease at the same rate as feed costs increase. From a maize silage with dry matter content of 30%, gross margins per bull of 451DM (Procedure I) and 429DM (Procedure II) can be achieved. With maize silage of only 25% dm, gross margins of only 283 DM/bull are attainable in both procedures. Comparing Procedures I and IIa with the same daily gains, as a result of the lower quality of the maize silage in Procedure IIa the gross margin decreases by 168DM/bull. With a hectare of maize under the existing price-cost ratios, gross margins clearly increase as a result of the lowered need of land per bull owing to the higher supplementation of concentrates. Again, the decreased profitability of maize silage of only 25% dry matter is proved.
Nowadays in the Federal Republic the use of chopped maize ears with husks as a basal ration in the fattening of bulls is intensively discussed. As there are no experimental results in the Federal Republic, only rough calculations can be undertaken. The starch unit content of this type of fodder is estimated to be 800 SE/kg of dry matter. Owing to the fact that after harvesting a main proportion of the maize plant remains in the field, the yield of starch units per hectare is at least 25% lower than with maize silage. With a net yield of 6000 kSE from maize silage per ha a yield of about 4500 kSE or 5.7 t of dry matter can be obtained with maize ears with husks. *DM = Deutsch Marks
TABLE 2 GROSS MARGINS OF FOUR PROCEDURES OF HIGH-PLANE FEEDING WITH MAIZE SILAGE (IN DEUTSCH MARKS, DM)
Item Maize silage 30% dm
Procedure I Procedure II
Maize silage 25% dm
Procedure la Procedure IIa
PROPORTIONAL OUTPUT DM total (550 kg)
DM/kg 4.20 2310
4.20 2310
4.20 2310
4.20 2310
PROPORTIONAL SPECIAL COSTS Calf (150 kg) Feed costs
DM/bull 1100 1100 1100
Maize silage 1) Soya bean meal ' Grain 3> Minerals 4) Feed costs total Others Interest on working capital TOTAL COSTS
190 382
32
145 332 154 28
209 485
42
(6%)
604 .62 93
1859
650 57 74
1881
736 71 120
2027
1100
143 382 210 32
767 62 98
2027
GROSS MARGIN DM/bull 451 429 283 283
FACTOR DEMANDS PER BULL Maize area Stable unit
ha 0.204 1.0
0.156 0.85
0.224 1.27
0.154 1.0
GROSS MARGIN Per ha of maize Per stable unit
DM DM
2210 451
2750 505
1263 223
1838 283
1) Proportional special costs: 930 DM/ha; yield 10 t of dry matter per ha 2) Price: 700 DM/t 3) Price: 500 DM/t 4) Price: 900 DM/t 5) Expenses for veterinary, water, electricity and so on.
518 TABLE 3 GROSS MARGIN FROM HIGH-PLANE FEEDING OF BULLS WITH CHOPPED MAIZE EAR SILAGE (WITH HUSKS)
Weight stage from ... to, Average daily intake from maize ear silage Soya bean meal Average daily gains Length of production period Feed consumption total Maize ear silage Soya bean meal
PROPORTIONAL OUTPUT
PROPORTIONAL SPECIAL COSTS Calf Feed costs Silage Soya bean meal Minerals Feed costs total Others Interest on working capital TOTAL
GROSS MARGIN
FACTOR DEMANDS PER BULL Maize area Stable unit
GROSS MARGIN per ha of maize per stable unit
kg
kg dm/day kg/day g/day days
t of dm t
DM
DM/bull DM
DM DM DM DM DM (6%) DM
DM/bull
ha
DM DM
150 - 550
5.0 1.2
1300 308
1.54 0.031
2310
1100
251 259 28
538 57 79
1774
536
0.270 0.85
1985 631
519 The dry matter content is assumed to be about 50%.
In order to avoid excessive fatness in the bulls, this type of fodder probably should be rationed. During the fattening period from 150 to 550 kg live weight an average of 5.0 kg dry matter from maize ear silage per day and 1.2 kg of soya bean meal should be fed. The consumption of nutrients so achieved is sufficient for daily gains of 1300 g. The calculation of the gross margin in Table 3 shows that this system results, as compared to maize silage, in higher gross margins per bull and per stable unit, owing to the lower need for concentrates and consequently decreased feed costs. However, the economic utilisation per unit of area lies well below the comparable systems of bull-fattening with maize silage from the whole crop. It cannot be assumed that the saving of silo space and costs of transport are large enough to compensate for the lowered gross margin.
In summary it can be said that under the assumed input-output relationships, as well as the present price-cost ratios in the Federal Republic, production, of maize silage of a dry matter content of at least 30% should be aimed at. The application of concentrates in addition to the protein supplementation should be as high as the growing potential of the bulls requires. This only applies under the condition that the replacement of maize silage through concentrates is not markedly higher than is assumed in the calculations, and as long as no higher fatness and a consequent increase in production requirement results from it. The use of maize ear silage as a basic feed in the fattening of bulls, in its competitive value at present price-cost ratios, will not be able to exceed systems of bull-fattening with maize silage.
Animal Feed Science and Technology, 1(1976) 521-529 521 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
FOR BEEF CATTLE, ALL FORMS OF MAIZE CAN BE USED
C. LELONG Institut Technique des Céréales et des Fourrages, Station Expérimentale de Boigneville, 91720 Maisse, France.
Maize, in the form of whole plant, ear or grain, dry or moist, can be used in simple feed rations without requiring excessive precautions. In beef production, the quantity consumed will vary with the type of conservation and the form of grain, but all can be· used ad libitum. In view of their high energy content, especially of the ear and the grain, these should be used solely for animals of high growth potential which will not fatten prematurely. The utilisation of these feeds is better in males than in females, in entire males than in castrated males, and in younger animals than in older animals. Thus, in young bulls there is a good conversion of these energy rich rations. In comparison with whole crop silage, feeding with the maize ear or grain induces fattening at a lower live weight, which is even lower in the earlier maturing breeds. Carcass weight depends on the diet and the breed of young bulls (Table 1).
The different forms of maize can well be used for the fattening of beef cattle after a period at pasture. Nevertheless the response of the animal will be as much a function of the management to which it has been subjected beforehand as the energy value of the fattening rations.
TABLE 1 POSSIBLE PRODUCTION OF YOUNG BULLS WITH DIFFERENT FORMS OF MAIZE Optimum carcass weight before which animals 'turn to fat'
Friesian Normande Charoláis Limousin Montbéliard
Whole plant maize (kg)
270 - 300 290 - 320 330 - 350+ 310 - 350+ 310 - 320
Whole plant maize + cereals (kg)
270 - 280 290 - 300 330 - 350+ 290 - 350 290 - 320
Maize ear (kg)
-270 - 30O 310 - 350 290 - 350 290 - 320
Maize grain (kg)
-270 - 300 310 - 350 270 - 320 290 - 320
522 VARIED DIET
With the use of the different forms of maize either alone or in conjunction with other products, highly varied diets can be obtained. We shall consider only the major ones, and those most suitable for use.
Whole crop maize silage is the most common and the most widely used. Appropriately supplemented with nitrogen and minerals, this constitutes a source of nutrients which is sufficiently rich for growth and fattening of early-maturing breeds of cattle, steers of all breeds, and young bulls (Friesian and Normande). A maize grain supplement is needed only during the last two months (2.5 - 3 kg per day). For most animals (except the Friesian) however, it'is advisable to add ground cereals (1 - 3 kg per day according to the breed). These contribute towards the improvement of the animals' performance and the homogeneity of the fattening. The cereal supplement could be in the form of moist or dry grain, or moist or dry ears. When the maize silage has a low dry matter content (less than 28%), dry cereal grains (like maize, wheat or barley) should preferably be used.
Although it is relatively stable in comparison with other herbaceous forages, the value of maize silage depends on the proportion of grain it contains and its dry matter content. A dry matter content of 28 - 35% is recommended, at the soft dough or hard dough stage.
Maize ear silage is well preserved in bunker silos. Its content of grain varies from 70% to 80% according to the type of harvesting machinery employed.
This ear silage, which is slightly richer in nitrogen than whole-crop silage and lower in its calcium content (see supplement in Table 2), contains sufficient cellulose fibre to be fed to animals on its own. Nevertheless the addition of some straw (400 to 500 g per day) or hay (800 to 1000 g per day) can be useful.
Moist maize grain needs some fibrous supplement. It can be ensiled in crushed form or preserved whole by treatment with propionic acid. In the latter case, it should be rolled before being fed to the animals. It can be fed ad libitum but needs
TABLE 2 TECHNICAL DATA IN NORMANDE BULL FATTENING WITH MAIZE (model Diet
Basic feed ad libitum
Energy supplement ground dry maize grain (kg/day) Protein supplement "soja 44" cake (kg/day) Mineral and vitamin supplement (g/day) C a / p . 1 8 / 8
Ca/P = 22/4 Fibrous supplement ad libitum
Growing and fattening period Initial weight (kg) Slaughtering weight (kg) Carcass weight (cold) (kg) Dressing percentage
Fattening period (days) Average daily gain (g/day) Dry matter intake (kg DM)
per day per kg live weight gain per kg carcass gain
Overall dry matter intake (kg DM)
whole-crop silage ear grain cake mineral and vitamin supplement straw
Whole crop
2.5 (during last 2 months)
0.9
150
-
130 550 303 55
420-380 1000-1100
6.55-6.80 6.55-6.20 11.6-11.9
2760-2595 2195-2075
120-120 380-345
65-55
silage
2.0
0.9
150
-
130 530 294 55.5
355-340 1120-1180
6.95-7.05 6.20-5.95 10.8-10.4
2475-2380 1495-1450
605-575 320-305
55-50
s)
Ear silage
-
0.8
180 straw
130 515 289 56
325-280 1180-1230
6.55-6.35 5.55-5.15 9.6 -8.9
2140-1985
1710-1580
260-250
60-55 110-100
Grain ensiled or treated with propionic acid
-
0.7
180 straw
130 500 280 56
300-280 1230-1280
6.25-6.10 5.10-4.75 8.7 -8.2
1445-1350 210-200
55-50 170-160
Whole dry grain
-
0.7
180 straw
130 500 280 56
295-285 125O-1300
7.O0-6.80 5.60-5.25 9.6 -9.0
2065-1940 ·
1620-1515 2O5-2O0
55-50 185-175
524 in addition to the nitrogen and mineral supplement, a fibrous supplement to prevent digestive disorders. Hay,which is generally consumed in larger quantities, is preferable to straw although the latter can be used if freshly distributed.
Grain and ear silages keep well in summer provided a sufficient slice is removed daily from the silo (at least 10 cm per day) and no water has penetrated the silage.
Maize grain treated with propionic acid is more suitable than grain silage for small groups of animals since there is no minimum quantity to be removed. Its use is more flexible and if grain crushing (which can be carried out every 2 or 3 weeks) provides problems of organisation, the grain can be fed whole although in this form its efficiency is slightly reduced.
Dry maize grain and ears are more easily harvested and stored than the moist forms. Less labour is required for harvesting and both can be used for fattening under the same conditions as the moist forms. Dry maize ears should be crushed with a hammer mill before feeding (every 8 to 15 days when the ears are dry). The dry grain can be fed ad libitum with either hay or straw, and crushing or rolling make little difference in its value. On the other hand, when added to maize silage, grain should be coarsely ground.
These dry feeds are well suited to the fattening of small groups of animals as there is no need for a high rate of consumption and feed excesses can easily be sold at the end of the season. Their major disadvantage is a significantly lower nutritional value than the corresponding moist forms.
One precaution should be emphasised in terms of ear or grain diets: the animals should be gradually accustomed to this new feed (at least over 3 weeks) to prevent too sudden a change in the rumen flora and the occurrence of acidosis.
VARIATION OF ECONOMIC RESULTS
For an appreciation of the economic interest of these different forms of maize harvesting and conservation, let us further consider a young bull beef production unit using the Normande breed of dairy cattle about which we have the most data.
525 Table 2 shows the type of performance obtained with such
animals and some of the diets mentioned above: the range of the results reflects a variation in the quality of the feeds or of the animals. In certain animals the performance, particularly in terms of growth rate, fell beyond this bracket. For other types of animal of different breeds, such as beef breeds, the absolute values of the zootechnical performance will be different from those for Normande calves. Nevertheless, in the light of the investigations carried out to date, one can assume that the modifications in performance due to diet are in the same order of magnitude for most young cattle. For the moment, it is not possible to predict the reactions of adult animals (heavy fattened bullocks or fat cows) to these diets, since this response is as much a function of their previous performance as of the diet.
In Table 3 the basic elements of the production costs of young Normande bulls under different nutritional conditions are gathered. The hypothesis upon which the economic calculations are made, are the following:
Situation: autumn 1975. Maize: calculated at the opportunity cost on the basis of 6 tons of dry grain per hectare at 615 F per ton. The yields of the different forms of maize are what can be expected in an average year in the areas where the maize is brought near to maturity. Harvest and storage costs: on the basis of one harvest per enterprise or agricultural machinery co-operative (including driver), transport and storage by mutual aid (labour not included). Maize grain supplement for maize silage: bought elsewhere at 70 c per kilo ground dry grain.
ι
Cake (soya or groundnut ): 1000 F per ton. Mineral and vitamin supplement: 1300 F per ton. Feed straw: 250 F per ton. 130 kg weaned calf: 8 F per live kg. Building: amortisation and financial costs: 150 F per animal place per year.
TABLE 3 ECONOMIC RESULTS IN NORMA
Basic feed
DM field yield (t/ha) DM available for feeding (losses included) (t/ha)
Opportinity cost in field (F/ha) Harvesting and storage costs (F/ha)
Number of animals fattened on each maize hectare
Production cost per animal (F) maize in bunker feed supplement weaned calf (130 kg) building amortisation financial costs animal losses miscellaneous expenses TOTAL
Production cost/kg carcass (F) Margin/animal (F) Margin/hectare maize (F) Margin/year-place in building (F)
.NDE BULL-BEEF PRODUCTION WITH MAIZE
Whole-crop maize silage +2.5 kg/d maize grain during last 2 months
11.0
9.0
+2 kg/day maize grain
11.0
9.0
3000
1000 4000
4.1-4.4*
1070-1020 500-455
1040 185-170 230-205
45 1O0
3170-3035
10.45-10 160-295 650-1275 140-280
6-6.2*
1160-1115 425-405
1040 160-150 205-190
50 100
3140-3050
10.70-10.35 95-185 580-1155 100-190
Maize ear silage
7.1
6.2
3000
770 3770
3.6-3.9
1040-960 395-375
1040 145-140 165-150
45 100
2930-2810
10.15-9.75 240-360 880-1420 270-420
Moist maize grain silage or prop. acid-treated grain
5.3
4.8
3000
. 700 3700
3.3-3.5
1120-1050 345-330
1040 135-130 150-140
40 100
2930-2830
10.45-10.10 150-250 495-880 220-310
Dry maize grain (whole)
5.3
5.1
3000
880 3880
3.1-3.3
1240-1160 345-330
1040 135-130 150-140
45 100
3055-2945
10.90-10.50 25-135 80-450 30-170
Maize grain bought in.
527 Expenses on animals: 8.5% per year on the total direct production charges. Losses: 2% of total direct production charges Miscellaneous expenses: water, electricity, veterinary expenses, 100 F per animal. No labour charges have been included for transport, storing
of forage, feeding or care of the animals. Labour varies with the structure of the farm (labour employed or family). On the other hand the choice of technique depends more on the labour requirements in peak periods than on labour costs.
The margins calculated per hectare, per animal or per place in the buildings, are established in terms of a sale price of 11 F per kg carcass.
THE FINAL CHOICE DEPENDS ON THE PRODUCTION UNIT
For a unit equipped with harvesting machinery and silos, and with no labour problems during harvest, or development projects for meat production, the mixture of whole-crop maize and a small amount of dry cereal supplement remains the most suitable.
This is well-known and has been established with tested equipment. It does have a heavy labour requirement during the harvest. This problem has been solved in areas where harvesting and transport enterprises exist or where mutual aid can be organised.
Cereal supplements are at least necessary àt the end of the fattening period if used regularly with maize silage. They improve the quality of the animals and are economically advantageous if the silage is of poor quality.
The production cost per kg carcass is slightly higher with maize grain bought at 70c per kg. However, this is compensated by the increased number of animals produced per hectare. The margin per hectare remains the same with or without cereal supplement.
In the case of a unit wanting to convert a large area of maize to meat production, the problem lies in the large amount of labour required during the harvest and the investments to be
528 made. Here, maize ear silage could be a solution. This involves lower harvesting and storage expenses and a higher growth rate (reduced nitrogen concentrate intake, lower financial cost and, in the case of calves of dairy breeds, lower amortisation charges on the building). The result is a lower production cost per kg carcass, but the smaller amount of meat produced per hectare brings the margin per hectare down to almost the same level as that obtained with whole grain.
The advantage of maize ear silage is in the work time reduction (25 to 30% less) during harvest and the lower investment in silos (40 to 50% less). The disadvantage lies in the use of a forage harvester fitted with maize ear headers which is neither well-known nor often used and needs a high power machine.
Moist grain maize ensiled or treated with propionic acid has still more advantages both from the point of view of labour and investment in storage. In addition, the harvesting machines have been well tested. However, a lower margin per hectare is obtained than with whole plant or ear maize silages because of the smaller number of animals that can be fattened per hectare. This technique can be useful if large areas of maize are to be harvested (at least 20 hectares) or when labour is scarce.
On small farms maize can be procured elsewhere, permitting an increase in the number of animals produced and a more effective use of the available buildings. Here the criterion is more the margin per animal or per place in the building than that per hectare. Maize harvested in the form of ear or grain silage could be more suitable since this yields a better margin per animal place occupied (especially if the field to be harvested is at some distance from the production unit).
Where small numbers of animals are to be fattened, the use of dry ears or grain, or grain treated with propionic acid, is more flexible than that of ensiled forms: there is no minimum quantity to be removed from the silo and the rations are easily fed. The margin per utilised hectare is however lower than with ensiled whole plant or ear maize. Considering the high performance obtained, the margin per animal or per day is as good with propionic acid-treated maize grain as with whole-crop silage.
Dry maize grain provides lower profits, but in many regions it still has the advantage of being the most easily harvested,
529 stored and distributed.
Another form of dry grain is provided by ears dried in cribs, then crushed. This is economically more attractive than dry grains but it requires much more labour during harvest and for distribution."
The choice between the different ways of harvesting maize is not easy. Various points have to be taken into account: climatic conditions (maturing of the maize), soil conditions at harvest, cattle market (type of beef cattle to be fattened, type of carcass that can be sold), and the cost of the different techniques which can vary slightly according to the ration and, obviously, to the production unit. Each farm needs to be considered with its own constraints (area to be harvested, available labour, existing machinery, investment possibilities) and its production aims.
The wide diversity of the forms in which maize can be harvested and stored provides the possibility of finding a beef production system which will best satisfy the farmer.
Animal Feed Science and Technology, 1 (1976) 531-544 531 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
BULL-BEEF PRODUCTI ON.FROM THE MAIZE CROP IN ITALY IN LARGE AND SMALL UNITS
M. RIONI and D. LANARI Istituto di Zootecnica-Padova, Italy
ABSTRACT
Bull-beef production in Italy is examined; the source of calves, breeds, housing, feeds more commonly used and feeding techniques, are briefly presented and discussed.
INTRODUCTION
During recent years we have had in Italy and particularly in the Po valley, a growing interest in intensive bull-beef production with the creation of many large units. This represents the result of a combination of many factors such as climatic conditions favourable to highly productive crops and particularly maize, economic returns in transforming forage crops into beef, a sufficiently high technical background of the farmers and, in certain conditions, low capital cost. Finally, the existence of nearby beef trading centres and a limited distance from borders, certainly had a positive effect on the location of feedlots.
At the present time, the Veneto region produces more than 40% (as carcass weight) of the total Italian bull-beef production. A recent estimate indicates that in this region up to 400 000 cattle can be housed. The remaining beef is produced both in commercial units in Lombardia, Piemonte, Emilia Romagna and Tuscany and in many small family units distributed over the whole country. Recently some attempt has been made to establish commercial beef units in southern Italy by means of the financial aid of "Cassa del Mezzogiorno". The striking difference between commercial units and family units is mainly based on the source of calves used. Commercial units, because of the demand of large numbers of calves of similar breed or weight characteristics, are mainly dependent upon imported animals, while family units use the national calf crop that derives from the 4 000 000 head
532
of the national cow herd. In this paper the characteristics will be described,first, of commercial beef units, and second, of family units.
COMMERCIAL BEEF UNITS
Animals and breeds
Calves which will be reared and fattened within commercial units come mainly from foreign countries and can be classified according to three categories:
a) Young calves, 15 - 20 days old b) Weaned calves c) Store cattle of 250 - 300 kg liveweight.
The choice among these three categories is strictly connected to the availability of calves during the year and depends also upon the calves' purchase price and feed costs. With high prices, because of their higher feed utilisation, young calves are preferred to store cattle. With low prices the reverse is true. It is important to underline that calf-rearing takes place in Italy, and can be performed either within the fattening unit, or in specialised rearing units which either import suckler calves directly or rear animals imported by fattening units.
In Table 1 some data on type, breed and country of origin of. imported calves are presented.
It can be seen that there are few European countries that do not contribute to our imports. Moreover, both store cattle and milk-fed calves are imported. Some of the latter are partially weaned. Live weight at arrival varies according to type of animal, breed and country of origin; there is a trend towards lower live weights notwithstanding the higher resistance to travel difficulties of heavier calves.
In Table 2, some data on Italian imports from EEC countries and third countries are reported. It can be seen that imports of live animals increased from 1.2 million head to 1.7 million in one year.
France has become the most important source of calves followed by West Germany and Ireland. Imports from third countries
533
TABLE 1 TYPE, BREED, COUNTRY OF ORIGIN AND LIVE WEIGHT OF CATTLE IMPORTED INTO ITALY FOR BULL-BEEF PRODUCTION
Type
Partially weaned Young calves
Store cattle
Breed
Friesian German Simmental German Brown Hereford χ Friesian Friesian Friesian Friesian Blue-Belgium Crosses from
beef breeds Limousin Charoláis
Crosses from beef breeds
Charoláis Limousin Blond d'Aquitaine Salers Aubrac German Friesian Friesian Simmental Simmental Simmental
Country of origin
Netherlands West Germany West Germany United Kingdom United Kingdom Ireland France Belgium
France France France
France France France France France France West Germany Poland Yugoslavia Hungary Romania
!—
Live weight at arrival
(kg)
70 - 75 75 - 85 70 - 75 45 - 50 45 - 50 45 - 50 45 - 50 60 - 70
60 - 70 60 - 70 60 - 70
250 - 300 250 - 300 250 - 300 250 - 300 250 - 300 250 - 3O0 220 - 250 220 - 250 300 - 330 300 - 330 300 - 330
TABLE 2 SITUATION OF IMPORTS INTO ITALY OF CALVES AND STORE CATTLE FROM EEC COUNTRIES AND FROM THIRD COUNTRIES (AIA, 1976)
Number of cattle Young calves Store cattle Total
Average live weight Young calves (kg) Store cattle (kg)
EEC Countries (*) 1974 1975
888 218 1 270 393 216 146 364 012
1 101 364 1 634 405
82 74 294 288
Third 1974
53 781 94 636 148 417
68 264
Countries 1975
38 208 30 969 69 177
84 290
Total 1974
938 999 310 782
1 249 781
81 -285
1975
1 308 601 394 981
1 703 582
78 289
(*) In 1975 the contribution of the different EEC countries was: France, 59.0%; West Germany, 25.8%; Ireland, 5.8%; Netherlands, 5.41; Belgium, United Kingdom and Denmark, 4.0%.
535
and particularly from Eastern countries (Poland, Yugoslavia, Hungary, Czechoslovakia and Romania) had undergone a significant reduction following the introduction of EEC regulations of July 1974. This regulation had an effect also on the type of animals imported, increasing the number of young calves bought, since most of the store cattle came from the Eastern countries.
At the present time the main source of store cattle is France. This production, available only during autumn when calves produced by suckler cows are sold, is appreciated mainly because of the economic advantages derived from these young bulls. The presence of store cattle only for short periods has directed the attention of importers to young calves that are available all the year round.
Although, because of the import situation, choice of breed is not always possible, the preference of fatteners is oriented towards French breeds, either pure or as crosses and towards German Simmental calves.
In Table 3 we have presented a picture of advantages and disadvantages of various breeds and crosses imported, according to the practical experience of farmers with commercial fattening units. Simmental calves give good results in our environment; Simmentals from the Eastern countries give less satisfactory results in dressing percentage than those from Bavaria. Friesian calves are appreciated, particularly those from Poland because of their good appetite, high adaptability to new feeds and slatted floors and especially for their very high resistance to pulmonary diseases. If the Friesian breed has to be considered a dual purpose breed, the Polish strain appears very satisfactory from a beef producer's point of view. Good performances can be achieved also with Friesians from the Netherlands, while calves from Ireland give carcasses which are less appreciated than some from other sources.
A brief comment, although derived from a limited number of cattle, can be made on Hereford χ British Friesian crosses. Their shortcomings derive mainly from the tendency to overfatness so that these animals reach slaughter finish very early at just over 300 kg.
Few comments can be made on the French beef breeds. Rate of gain, feed utilisation, dressing percentage and yield in retail
536 cuts is outstanding, but several problems are encountered during rearing. First, most of the store cattle are affected by internal and external parasites that require immediate treatment. Secondly, their ability to live in the limited space available is rather low so that they require a rather long adaptation period. The same happens for adaptation to the main feeds used in commercial units. Finally, both store cattle and young calves are particularly susceptible to pulmonary diseases. Crosses from beef breeds like Limousin and Charoláis have better resistance than pure-bred calves.
Calves belonging to Salers or Aubrac breeds, although less appreciated for carcass quality, appear well able to withstand Italian rearing conditions.
The shortcomings observed with animals imported from France and particularly with store cattle, are well known to French breeders and exporters; recently Cottereau (1976) , after a visit to Italian beef producers and a meeting with Italian experts, presented a sequence of treatments to which calves should be exposed before exporting to Italy. They include both feeding and health precautions. The results of these treatments, tested on about 12 000 young bulls, were particularly satisfactory, reducing significantly both disease and the incidence of losses.
In Table 4 some data are reported on a comparison made between treated and untreated calves in a fattening unit. Although collected under practical conditions, these data can give some useful indications of the value of health and feeding treatments before importation. The incidence of losses was higher in untreated calves -than in treated animals (10.96% vs 4.44%). Moreover, respiratory diseases greatly contributed to removal of untreated calves. If we look at breed effect and mainly at the data from the Charoláis and its crosses, it appears that the French crosses show high resistance in comparison with pure-bred Charoláis calves. These results appear to support the classification reported in Table 3.
Housing
In Italy, bull-beef production is carried out mainly in a closed environment, since, as a result of climatic conditions
TABLE 3 BREED ADVANTAGES AND SHORTCOMINGS ACCORDING TO PRACTICAL EXPERIENCE OF BULLBEEF BREEDERS IN ITALY 1
Breed
German Simmental Simmental from Eastern
countries Friesian from Poland Friesian from France Friesian from Netherlands Friesian from Ireland Charoláis Limousin Salers Aubrac Hereford χ Friesian Charoláis crosses Limousin crosses
Growth rate
good
good good good good good
excellent excellent good good
medium excellent excellent
Dressing percentage at slaughter
good
medium medium medium medium
mediumlow excellent excellent medium medium good
excellent excellent
Carcass yield in retail cuts
good
good medium medium medium
mediumlow excellent excellent medium medium
mediumlow good good
Suitability to confined environmental rearing
good
good excellent good good good
medium medium good good good good good
Resistance to disease
good
good excellent good good good low low good good good
medium medium
TABLE 4
EFFECT OF TREATMENTS BEFORE IMPORTATION ON THE INCIDENCE OF DISESE AND LOSSES OF STORE CATTLE DURING THE REARING PERIOD
Number of head Weight at arrival (kg) Days on trial Average daily gain (kg) Number of animals removed Incidence of losses (%)
Causes of removal Respiratory diseases Other diseases Low growth rate Accidents Metabolic diseases
Treated animals Charoláis Crosses
416 278.2 93 1.5
23 5.52
21.74 8.70 8.70
17.38 43.48
259 287.9 97 1.6 7 2.70
42.85 42.85
14.30
Untreated animals Crosses
73 2 50 130
1.4 8
10.96
75.00 12.50
12.50
539
and high land value, grazing systems are rare and limited to well-defined periods of the year. It appears particularly suitable for animals that will be employed for reproduction; for example, the pastures of the Alps in northern Italy are used for roughly 100 days per year by young livestock or dairy cows which, in this way, have an opportunity to reduce the effects of their long period of confinement in closed barns.
Because of this situation housing has received a great deal of attention and many different solutions have been considered. We will briefly examine first facilities for housing calves during weaning and then facilities for bull-beef production.
At the end of the sixties, early rearing was carried out in modified dairy sheds, divided in pens of 4 - 12 animals each and using straw for litter. More recently, buildings previously used for broiler production or veal production have been adapted for this purpose. At the present time, because of the increasing number of calves that are reared, new buildings, specially designed for rearing, with a capacity for 200 - 300 head each, have been built in specialised calf-rearing centres. These large rearing units are operated by cooperatives, taking advantage of particularly favourable loan conditions in which construction costs are partially supported by government grants.
The more modern buildings sometimes have sophisticated forced-air ventilation and heating systems: the inner space is usually divided into two rows of pens with a feeding gangway at the centre. Pens can house from 10 to 12 calves and either permanent straw litter or concrete slatted floors covering tanks for the collection of manure, are employed. The latter solution allows a certain reduction in labour and straw coats and seems particularly suitable for the summer period or for calves weighing 80 - 90 kg, while, with light animals and in winter time, more digestive troubles are encountered with this type of building. In the more recent buildings, pens of 8 - 10 sq m that can house 6 - 8 calves are used. The slatted floor of the cages is roughly 70 - 80 cm above the barn floor. This facility allows a constant control of the health of the calves. The calves are kept in the rearing centres until they reach a liveweight of 120 - 140 kg, when they are transferred to fattening units.
540
Housing in fattening units has undergone a similar evolution during this time. At the beginning, many units came from adapted dairy barns or other buildings; the difficulties of handling large amounts of bulky feeds and of manure in a restricted space, together with problems of insufficient air exchange, have led many farmers to erect completely new buildings specially designed for this purpose.
The first ones followed the old scheme of a central feeding passage with a row of pens along each side. Permanent litter was used; each pen could hold 15 - 20 cattle with 3 - 4 sq m per head. This type of building, although allowing good results, had some shortcomings because of the high surface area per head and mainly because of the costs of straw distribution and manure removal.
The trend towards reducing costs has led to the introduction of concrete slatted floors with tanks for liquid manure collection. By this means, straw, the cost of which is continually growing, was completely eliminated, manure disposal greatly facilitated and finally, the covered area per head reduced.
The introduction of slatted floors, the use of which has been greatly increased, can give various disadvantages. First of all, initial cost is higher, although balanced by a decrease in covered area; secondly, the frequency of accidents to limbs is increased, and finally, tail necrosis can become a serious problem.
Completely closed buildings that can hold up to 1000 cattle have been built, but increasing size, and greater numbers of animals housed, have shown the limits of these closed barns because of insufficient ventilation. As a result, these structures are now becoming less frequent, and sheds with a completely open side are now more favourably considered. Cattle show no signs of discomfort in either hot or cold weather; moreover the incidence of respiratory disease, the high frequency of which is characteristic of winter time in northern Italy, is significantly reduced, mainly because of a high rate of air exchange with no draughts.
Finally in this short review we have to report on some examples of "feed lots" recently introduced in Italy. These have large paddocks with no flooring, can have a protected feeding area but often do not provide covered areas.
541
On these structures we do not have, at the present time, sufficient data to be able to express any opinion, although the first results observed during summer do not seem unfavourable.
Feeds and feeding
If we look at feeding systems for beef production we will be astonished by the great changes that took place in northern Italy over a period of ten years. The developments in feed costs and the knowledge of the results obtained by many researchers have undoubtedly contributed to these changes.
From a feeding system where hay and farm by-products were the principal components of the diets, and concentrates were used for short periods in order to reach the necessary finish for slaughter, following the knowledge of Preston's researches, ration composition changed greatly with increasing levels of concentrate in the diet. This took place in the more modern agricultural areas of our country and where there was a tradition in beef production.
Following Preston's techniques, high levels of nutrition were employed in rations for beef cattle, to produce high growth rates with well finished carcasses. At the same time, live weight at slaughter was reduced and often did not exceed 370 - 450 kg, according to the breed used. During this period, research was devoted to considering the effect of physical treatment of cereals on animal performance. Particularly studied were the use of steamed and rolled maize grain and reconstituted and rolled cereals in comparison with ground grains, (Bonsembiante et al., 1968, 1969). .These experiments showed the importance of cereal treatments and have been extended to the identification of the best combinations of treated grain and different roughage sources.
Following new technical knowledge and economic situations that led farmers to increase slaughter weight, products derived from the maize crop have been used in different ways. The utilisation of the whole maize crop has become more attractive. This trend appears to be justified by the higher yield of nutrients per unit area of land made possible by harvesting the whole maize crop at the dough stage, and by the reduced cost of this forage. As a consequence, maize silage represents the main component of a fattening diet, especially in certain periods of the rearing
542 cycle. It can be employed alone or in various combinations with other components of greater energy concentration..
As previously reported, two categories of cattle are used in commercial fattening units: calves and store cattle. Evidently they require different feeding techniques, mainly at the beginning.
If we consider the young calves, milk feeding represents the first part of the long rearing period. From 45 to 60 days are necessary before weaning, according to the live weight of the calves and the season. With light animals and during winter, the liquid feeding period is lengthened. Daily gains during this period vary from 0.7 to 0.9 kg. An average of 21 - 28 kg of milk powder, 20 - 30 kg of hay and 70 - 80 kg of a concentrate mixture are consumed. After weaning and up to 140 - 150 kg live weight calves are fed good quality hay, concentrates and limited amounts of maize silage that sometimes is fed also during weaning. Urea can be used in the concentrate in small amounts.
From 150 kg live weight to 300 - 350 kg, feeding is characterised by a large use of maize silage. An average ration is made up of maize silage (70 - 80%), energy supplement (10 - 20%) and protein, vitamin and mineral supplement (10%). At the present time, because of the high cost of maize grain, dried beet pulp is largely used. During the final rearing period, which can be considered a fattening or finishing period, the ration is modified in order to increase its energy concentration. The maize silage content decreases to 50 - 60%, and concentrates are correspondingly increased. These changes are made according to animal breed, slaughter weight and the feeding treatment received during the rearing period. As reported in Table 1, many Friesian calves are imported. Because of their early maturity and tendency to over-fatness at light weight, it is necessary to reduce the ration energy concentration of the diet so that the concentrate level is kept to low values during the whole rearing period.
With bulls of the French beef breeds or their crosses, diets with high nutritive levels appear more satisfactory, especially during the final period, if carcasses with good finish are desired.
When· store cattle, reared on pastures, are bought, in order to take advantage of compensatory growth, rations of high energy concentration give the best results.
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Few comments can be made on the various kinds of energy supplement used in finishing rations. Concentrates from the maize crop are very common; moreover, barley, dried beet pulp, molasses and other industrial by-products are employed. As nitrogen sources, soya bean meal is the most important, followed by other extraction meals; urea is always present in protein supplements and sometimes molasses subjected to the Steffen process is employed.
Factors that affect feed choice are strictly connected to the availability of the product during the year and to its cost. An attractive product, already well known, that could be used as a nitrogen source is dehydrated poultry litter, but its use is forbidden by law.
Family units
Bull-beef production is accomplished also in numerous small units spread over the whole country. In northern Italy fattening is connected to milking herds of Friesians, Friuli Red Spotted and Italian Brown Swiss. The Piedmont breed, normal or double muscled, is reared in most of the family units of Piedmont, producing a highly appreciated beef animal.
In the centre of the country, Italian beef breeds reared are the Chianina, Romagnola and Marchigiana, kept either in barns or at pasture. Local breeds are used in southern Italy.
Bull-beef production in these units is still tied to traditional methods; maize silage is seldom used, and hay of various kinds, supplemented with a limited amount of concentrates, is used. Milk feeding is always very prolonged and often presents a problem. No milk replacers or starters are used, so that whole milk and hay are the major ration components.
With these techniques, no homogeneity in the final product is possible, and this greatly affects the economic output of these farms. Moreover, the rearing period is particularly lengthened and high live weights are reached in order to produce a satisfactory finish.
More technical and socio-economical assistance seems desirable for these farmers, especially in southern Italy, in order to increase the income of these family enterprises.
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We are aware that with these brief notes it was not possible to examine all of the different solutions adopted for bull-beef production in Italy but we hope that a general impression of our conditions has been given.
REFERENCES
AIA, 1976. Associazione Italiana Allevatori. Personal communication. Bonsembiante, M., Rioni, M. and Lanari, D., 1968. Diete ad alto livello
nutritivo con granoturco vaporizzato schiacciato o in farina nella produzione del vitellone. Alimentazione Animale, XII, 145.
Bonsembiante, M., Rioni, M,and Lanari, D., 1969. L'effetto della vaporizzazione e rullatura del mais e della presenza di fieno e di insilato sulle caratteristiche de liquido di rumine e sulle "performances" del vitellone. Alimentazione Animale, XIII, 5, 351.
Cottereau, Ph., 1976. Prophylaxie des maladies infectieuses et parasitaires des veaux dans les grandes unites d'engraissement. Revue Medicine Vétérinaire, 127, 4, 575.
Animal Fectl Science and Technology, 1 (1976) 545-552 545 lilsevier Scientific Publishing Company, Amsterdam - Primed in The Netherlands
DISCUSSION ON SESSION 5
D. Lanari Italy
There are four different topics, first the effect of live weight on daily gain, then I think we can put together the papers by Dr. Walter and Dr. Lelong under the heading of economic aspects of beef production with the maize crop, and then there are beef production systems. Finally, there are a lot of points that we have had from Professor Vetter.*
H. Schneeberger Switzerland
I have a question for Dr. ¿obié. Can you give me more information about the development of daily gain? In the last treatment was the daily gain lowered all the time or only in the final period?
T. Cobic Yugoslavia
The daily gain was lower only in the final period.
J.B. Kilkenny UK
Dr. Cobié, did you do any carcass assessment, the amount of total fat in the carcass and the amount of subcutaneous fat?
T. Cobic
No. Thiå p a r t i c u l a r i n v e s t i g a t i o n was c a r r i e d out under con t r ac t with one of our customers . We have big farms and they were i n t e r e s t e d in t h i s p a r t i c u l a r problem but only t o the po in t of k i l l i n g - o u t pe rcen tage , so we did not proceed any f u r t h e r . We have no idea but we would l i k e to propose to t h i s conference t o extend t h i s type of i n v e s t i g a t i o n to ca rcass q u a l i t y because i t becomes more and more impor tant , in t h i s country as in o ther c o u n t r i e s , because everybody has a s tandard on meat q u a l i t y and i t should be developed in t h i s country t o o . *Professor Vetter earlier presented a review of his research, which is not available for publication, on the utilisation of the maize crop, its byproducts and animal wastes, by beef cows and feed lot cattle. This review will appear in Animal Feed Science and Technology, volume 2, number 2.
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D. Lanari
We will now consider the papers of Walter and Lelong.
J.B. Kilkenny
In these two papers there is a different approach to the output of the various systems, Dr. Walter used a standard slaughter weight for each of the comparisons, with very different levels of daily gain. Mr. Lelong allowed differences in slaughter weight to take account of different live weight gains. Our experience is that there is a very close inverse relationship between daily gain and slaughter weight, much bigger differences in fact, than Mr. Lelong allows. I would like' to ask whether these slaughter weights were at a standard level of fatness or whether there were still differences in fatness occurring, and also to ask both of them whether differences in slaughter weight and fatness should be reflected in different prices for the different systems.
C. Lelong France
The slaughter weight depends on the breed. We cannot have the same slaughter weight and same fatness with early breeds like the Normande,Montbeliard as with the Simmental. The aim is to have the same state of fatness at slaughter. In different markets there are different prices owing to the difference in market conditions. For beef breeds such as Charoláis, Limousin or cross-breeds, it is possible to have the same slaughter weight with whole crop maize silage diets or ear and grain silage diets.
K. Walter West Germany
In Germany there is a new payment for weight, and a slaughtered bull is only bought by weight. It is considered that if it is 550/600 kg it is good but there is no interest in the daily gains the animal made during the fattening period. There is also a difference between breeds. Simmentals have
547
higher prices than Friesians and the Charoláis sometimes have higher prices than Simmentals but there is no payment for quality and therefore I took the same final weight for all procedures.
H. Schneeberger
I think experiments in Switzerland are very similar to those made in the UK.
D. Lanari
In our country we have to fatten Friesians or French breeds, and because of the very high calf prices we have increased weight at slaughter so that we use only maize silage with the Fries-ians while with the French breeds we add more concentrates in order to get the heavier weights and not very high daily gains and a constant finish.
D. Oostendorp Netherlands
Was Dr. Walter's paper entirely based on calculations or have these been confirmed by experimental work?
K. Walter
The calculations are entirely based on the figures for the requirements for maintenance and production, but these figures have been tested and confirmed in many experiments so I think they will be near to reality. On our own farm we are conducting experiments with Simmental bulls that reach daily gains of nearly 1.3 kg through the whole fattening 'period if we give 1.5 kg soya bean meal and 1 kg grain per day. The daily gains are changing during the period, increasing to a live weight of about 400 - 450 kg where they reach the highest point, and then decreasing to perhaps 1.0, 1.05 or 1.10 kg at the end of the fattening period.
548
R.J. Wilkins UK
Could I put a question to Mr. Lelong? In his analysis there seems to be a general conclusion that on relatively small farms, there may be attractions in using grain or ear corn rather than whole crop maize silage. One of the reasons that you stated for this, was that with grain feeding it is possible to procure more grain from other sources and therefore increase, perhaps, the number of animals that can be fed on a particular farm. I wonder whether, in your analysis, you had considered for the relatively small farmer, the possibility of making whole-crop silage on his own farm, to get high yields of dry matter per ha and then supplementing this with grain bought in from outside?
C. Lelong
On the small farms which have many other enterprises than beef production we often find 8, 10, 12, less than 20 animals to be fattened. It is quite impossible to cut a sufficient quantity of silage and I prefer to advise the right diets. In this case there is no problem of yeast or moisture in the silo and, of course, profit is lower, but there is no choice. This case is very common in France in several crop regions.
J. Harte Ireland
Surely the main issue of the small farms is that one would not have the equipment for making silage and I would not like to make silage with a horse and cart. It is much more reasonable to move very dry material.
T. íobic
I would like to put a question to Dr. Lanari. How do you manage with this slurry; liquid manure, put into lagoons and are there any legislation problems regarding pollution?
549
D. Lanari
There is increasing concern about air pollution when you transport the manure. Up to now the problem is not very great and there is no law on this. There is a recent law that for lagoons you are obliged to cover the whole surface before putting in the manure in order to avoid spillage, and contamination of soil water. Usually these large units of liquid manure are used for fertiliser - on maize crops usually - in winter time, during October/November, or sometimes they are obliged to dispose of the manure during the summer time. So there are several possibilities and the more recent one is to put the manure down after ploughing "and then the second time you cover the whole thing by ploughing. Colleagues are starting studies with a big container with special apparatus so that you can collect the manure and with the same container spray and insert it into the soil. However, we have to face this problem because it is growing now. There is also a growing concern in the surrounding population, they do not like the smell, which is pretty heavy during the summer.
T. Cobic
I meant the solid particles coming up to the top. Do you agitate these?
D. Lanari
They have a special pump so that they can mix the liquid and the solid particles.
J.C. Tay1er UK
We all found Professor Vetter's talk fascinating and he gave us a lot to think about. However, when considering how we can apply some of these ideas and possibilities to the European scene there is one point we should remember. In the USA there are 40 million beef cows and 12 million dairy cows, whereas in the Community alone (I do not know about the other ten countries)
550
there are only 6 million beef cows as against 25 million dairy cows. So the ratio is very different, and for methods of utilisation of stover with beef suckler herds, which you have discussed, the problem with us would be rather different because we do not have so many animals with a low productive requirement.
R.L. Vetter USA
I would like to ask a question in return, Dr. Tayler. Your number of beef cows in relation to your production of maize, what is the ratio?
J.C. Tayler
This is rather more difficult because Dr. Wilkinson gave us the figure of 8 million ha of maize in the 19 countries as against 30 million in the USA but the figure I do not have is the number of cattle and the ratio in the ten neighbouring countries to the Community. However, we know that there are virtually no beef cattle in Yugoslavia, and in Finland, Spain etc., probably not many. In other words the ratio is still likely to be very much in favour of dairy cows in all of the countries and if so, you can reckon you have got 30 million ha of maize against 40 million beef cows. We have 8 million ha of maize against only 6 million beef cows in the Community and probably not very many, as such,in the other ten countries outside the Community. I cannot give you exact figures on that; I am only making a general point.
R.L. Vetter
I was going to bring in the point of the cost. If you look at it aside from the countries producing maize silage, I think in the EEC countries, in 1975 you produced 14.5 million metric tonnes of maize grain, with 95% of that produced in France and Italy as grain. If you look at the total of western Europe you have 18 million metric tonnes. Spain
551 produces a large percentage of that difference. Now , of the eastern countries, Yugoslavia, Hungary and Romania, make up 87 - 90% of the grain production of those countries. With dairy production you need grass silage, you need energy, most of the lactic material will be used by dairy cows so the maize silage crop is very pertinent there. Your point is well taken that we do have a larger number of beef cattle.
M. Chenost FAQ
I would just like to make a point in relation to Professor Vetter's paper. I would like to draw the attention of the audience to the fact that the Animal Production Division of the FAO is very much interested in this policy to stress the need for new feed resources. Of course, for you, maize is much more considered as a feed, but for the developing countries it is considered still as a food. Therefore, these conventions on feed for U3, are somewhat expensive. The Animal Production Division has therefore decided to focus its thoughts for one year, on the utilisation of new feed resources, on what we call unconventional feed resources which could be considered as by-products, not only industrial by-products, but materials from different crops, recycled animal waste, etc. The first step to implement this policy will be the organisation of a technical consultation on the utilisation of these· new feed resources. This will be held in Rome on the 22-24 November 1976 and the official information is being distributed to your appropriate Government departments.
J.S. Da Costa Portugal
Professor Vetter, you mentioned that in the protein in your manure, 50% is amino acids. What happens to this half of amino acids when you carry out sterilisation?
R.L. Vetter
If you look at a high concentrate ration, the microbial mass as a percentage of the dry weight approaches 30 - 35%,
552
sometimes higher. So this is the main source of your alpha-amino nitrogen or the microbial cells and, of course, there are some of the enteric organisms. Its biological value for monogastric species would be low. In that remaining 50% at least 20% will be ammonia and other NPN compounds. However, when it is composted the microbial fraction would be partially digested, and it would be a usable energy source.
F. de Boer Hetherlanâs
I would like to ask Professor Vetter about the Food and Drug Administration (FDA) in relation to the recycling of manure. You mentioned that six of your States allowed recycling of manure for feeding puposes but I thought that the FDA was a Federal association. What is the specific base to allow it in six States and not in the others?
R.L. Vetter
Each State has its own feed control officials and if they receive an application for recycling then if the State feels it does not have the data to classify the product as a feed ingredient, they will go to the FDA. The FDA has not given encouragement to the States. Some States have taken a decision on their own to classify manure as a feed ingredient. For instance in Iowa we have had several companies which are dehydrating poultry waste and they made application to the State. The State has the authority to require this because in the American Feed Officials' manual or handbook, dried poultry waste was cleared several years back as a feed ingredient, if properly sterilised and handled. The FDA want to see enough data provided and it looks very positive from the work in Europe and elsewhere, notwithstanding that problems might arise.
D. Lanari
I will now close the session and thank those who presented papers, and all of you, for your co-operation.
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SESSION VI
REQUIREMENTS FOR FUTURE RESEARCH
Discussion session in three separate groups, followed by a summary of conclusions presented by recorders and general discussion of the needs for future research in relation to the research programmes of the participating countries.
SEPARATE SESSIONS
Subject group Discussion leaders and recorders
A. Agronomy, harvesting, conservation A. Monteagudo and E. Zimmer Β. Nutritive value, nitrogen T. Cobic and R.J. Wil kins
metabolism and research techniques
C. Systems and economics K. Walter and A. SrecKovic
Chairman: J.C. Tayler
Animal Feed Science and Technology. 1 (1976) 555580 555 Elsevier Scientific Publishing Company, Amsterdam Printed in The Netherlands
REQUIREMENT'S FOR FUTURE RESEARCH (a) General discussion prior to separate sessions Dr. Tayler opened the discussion by reminding delegates that
there was considerable potential in the nineteen countries of the COST group to increase beef production. The third countries outside the European community had 66% of the land but only produced 22% of the total quantity of beef. The conference had heard results of recent research into the production of beef from maize and the time had now arrived to consider what research was needed in the future, what facilities were available for such research and how such research might best be coordinated.
The discussion then centred on topics which might be considered in the group discussions which were to follow. The· following topics were raised:
Agronomy: (i) Selection for yield of grain rather than yield of total dry matter, Yield of energy per hectare from forage maize compared to other forage crops, Optimal plant populations for forage maize and for grain maize, The role of maize in mixed or multiple cropping Adaptation of maize to northern countries, Increasing the protein content of forage maize. Fertiliser and irrigation problems. Improving nitrogen utilisation from diets based on maize, Increasing intake of silage and utilisation of ingested energy, Improving laboratory assessment of the nutritive value of forage maize, The effect of nutrition on carcass quality. Variation in animal response to maize silage, Utilisation of NPN and other sources of supplementary Ν and economics.
(ii)
(iii)
(iv)
(v) (vi)
(vii) Nutrition:(i)
(ii)
(iii)
(iv) (ν) (vi)
556
Systems: (i) Effect of housing on performance (ii) Comparative performance of systems based on
maize with systems based on other feeds, (iii) The impact of mixed cropping on systems of
beef production, (iv) Standardisation of economic terminology, (v) Health of cattle given maize silage and
influence of fungal toxins in maize on health of beef cattle.
557 REQUIREMENTS FOR FUTURE RESEARCH (b) Report of separate sessions, general discussion and relation
ships with current research programmes
J.C. Tay1er UK
I now ask the recorders to come forward and give the conclusions of their meetings. Remember to give the reasons for choice of research priorities. Towards the end of the time on each of the three subjects, we will ask the countries' participants, who are listed in Appendix 1, if they would briefly indicate what facilities they have in relation to the programmes that we have been talking about and what sort of contribution they feel their own country can make. Will the recorder of the first subject group Λ, on Agronomy, harvesting and conservation, Dr. Zimmer, present conclusions of his group.
E. Zimmer West Germany
This group discussed the list of items which I gave and we draw the following conclusions.
Firstly, it was strongly agreed that there is a need for breeding a forage maize to cover the general goal of improving yield to give maximum yield of energy as well as maximum energy concentration, and the northern regions agree in this combination. We have two hypotheses for doing this job and these are our recommendations to the breeder. Firstly to have a higher sugar content, which may mean changing the type of assimilation in the maize plant; and secondly to have a better cellulose digestibility in the maize plant.
A point of minor interest for breeding was to deal with the socalled 'green maize'. There are several regions, over the whole of Europe, which are interested to have a maize for grazing during summer time or for intercropping, and this maize should be of a completely different type, maybe with more tillers or very short growth periods. We concluded that this a point of minor interest.
Under the heading of agronomy we concluded that there is much disagreement in the literature and in the data given to the
558 Conference, concerning, for example, the right plant density and its effect· on the feeding value of the maize. Each country has its particular recommendations but, as you remember from Dr. Phipps' report, there is a complete new direction with much higher densities in the UK. We discussed this item and the group concluded that it might be good to extend the already existing programme from Eucarpia, which has spread all over the European countries and localities in different ecological situations, in the direction of evaluation by the animal, because there is a big gap between the findings of the economists and the needs of the nutritionists and the demands of the animals and we should try to fill this gap. We have to ask the people from Eucarpia whether this could be possible or not, but we feel that in selecting standard varieties, with controlled economic factors, and then going on to an evaluation by feeding trials, we may get much more knowledge and can fill this gap of which I spoke.
For irrigation, there is a general and urgent need for better use of water, but we concluded that this is mainly a question of better facilities, better education technique, lowering cost, and it is more a technical problem than one of research. On the other side, efficiency of water use by different varieties is, maybe, a problem of the group of the southern countries of our community here and it was concluded that one should go in for more planning of details of the experiments involved - genotypes, fertilisation, densities and irrigation too, and this for the countries round the Mediterranean to find better efficiency of water use.
With fertilisation, we cannot give any recommendation because individual situations in each country are too different. We can only state that the general tendency is to decrease the amount of nitrogen.
Under the last heading, conservation, we dealt with three items and concluded that improving quality as a general aim, also to the farmer, is a problem of high interest, but there is already established a fairly good collaboration between the existing groups of specialists dealing with this and we already know the recipes for good management and it is more or less a question of better extension to bring these data to the farmers.
559
The southern group stated that the right particle size of chopped maize silage is a problem, or even how far to chop and grind ear corn. On the other hand for the northern countries where we do not have such hot summers, or such an advanced stage of maturity, it is not a problem. For southern countries we recommend a combined experiment to solve this problem of the right fineness and the right particle size.
The third problem of common interest is heating. Heating or so-called after-fermentation is a problem for all countries which conserve maize, equally for the conservation of whole-crop maize, grain and high-moisture maize ears. Here we need further research but we also conclude that only a few groups of specialists already established in Europe can cover such research. Nevertheless, all the countries are highly interested to have more detailed data and to have a better look at this particular problem. Therefore heating is of common interest.
J.C. Tayler
Thank you very much Dr. Zimmer. This subject is now open to anyone else who was not in on that detailed discussion.
In relation to your proposal to extend the Eucarpia programme, I know nothing of that programme in detail, but I wonder whether there is a need for a working party to look into that? When producing a standard method for universal use it may be necessary for this to be formulated by somebody.
You proposed more evaluation by the animal, and perhaps some standard method would be needed, or were you speaking in rather a general sense?
E. Zimmer
The optimum would be to go into feeding experiments - of course, including digestion trials and feed intake experiments. On the other hand we discussed whether we can establish a prediction formula by using chemical parameters as well as digestibility in vitro or such things, to get nearer to the requirements of the animals with our findings than we do up to now, because we know the Eucarpia programme of field trials, and for
560
feeding experiments we need a much greater quantity of the crop. However, we think that this should be discussed and maybe some standard varieties could be grown over all situations - or most of the situations of Europe - parallel to the Eucarpia programme and under the same standardised conditions, in an amount sufficient for feeding experiments. This is also a question for the nutritionists; our feeling was that we should try to build a bridge between these groups.
J.C. Tayler
Could we now ask for suggestions by any of the national representatives as to where they might have work proceeding or planned which is linked to this particular set of proposals. I think you have work proceeding on some of these aspects in Belgium.
Ch. V. Boucqué Belgium
In our fattening trials we always monitor the quality of the maize and maize silage and, of course, the losses. Every wagon-load coming in to the silo is weighed, and every portion which is taken out of the silo is also weighed.
B. Cottyn Belgium
There are several factors; we study digestibility in vitro and also use the nylon bag technique and measure cell wall constituents .
K.G. Mølle Denmark
We have some work concerning additives in the ensiling technique and the heating problem among other things.
Y. Geay France
Most parts of the list are studied in France; first the
561 breeding of grain to improve the production of crude protein, and breeding of maize forage, especially maize for silage, to improve its feeding value and the level of intake. Young bulls are used to study the nutritive value of new varieties of maize forage.
J . H a r t e Ireland
I am not clear whether I heard proposals to breed maize for lower temperatures but we would naturally help out in that part.
Β. Laber Austria
We make a different test every year with different varieties especially for use in the hills in the future. This is very important for us.
Ms. L. Syr j a l a Finland
We have an interest in finding varieties which will grow on our farms and we are testing varieties. We are also interested in the prediction of nutritive value.
A. Monteagudo Spain
We work with hybrids with high protein content and are studying agronomic factors.
T. Cob i c Yugoslavia
We have a very big interest in maize as a second crop under irrigation and this is included in the list on agronomy.
D. Merqounis Greece
We have no special programme on agronomy.
J.C. Tay1er
We will now move on to nutrition and I ask Dr. Wilkins to report.
562 R.J. Wilkins UK
The large number who attended our group probably contributed towards our not being able to make definite conclusions like those that Professor Zimmer distilled from his conference.
We did go through a number of items and I will discuss these under five headings:- Digestibility; Efficiency of energy utilisation; Voluntary intake; Nitrogen metabolism with maize silage; and Carcass composition in relation to the feeding of maize.
At the start we agreed not to consider dehydrated whole-crop maize, because we could not forsee an important place for this product in research over the next few years and we limited our discussion very largely to maize silage.
On digestibility, our discussion was running somewhat in parallel to that of Group 1; we realise that there is a big need for standardisation of methods here.· There seem to be particular problems in measuring digestibility of maize in vivo. We have material which is deficient in minerals and nitrogen and there is likely to be an effect of class of stock on the value which is obtained, and an interaction with the degrees of maturity of the crop, i.e. whether you have hard grain or not. We did manage to produce tentative recommendations for methods for determining digestibility in vivo and we felt that this should be done wherever possible in feeding experiments with maize.
We decided that sheep should be used and fed at a controlled intake around the maintenance level; that a supplement should be used to raise the protein content of the feed to about 11%, although we did not specify exactly how this would be done, and also that supplementary minerals should be given. Although we made some decisions, it would need somebody to put a paper together, or a working group, to prescribe something in more detail.
We were very concerned about laboratory techniques to predict digestibility as there had been evidence in the earlier discussions in the conference, of instances where digestibility in vitro does not really seem to give the answer we want and there was a lot less enthusiasm for using crude fibre or other measurements of fibre for predicting digestibility of maize
563 silage, but our views on this were tempered somewhat by the fact that the digestibility of maize silage does not vary very widely-Although we thought that there was a need for investigations of the laboratory prediction of digestibility of maize silage, we learnt that these were in progress in several countries. We want this continued, but we did not really give highest priority to this in our discussion.
We very much held the view that, particulary in northern Europe, where we might be growing maize at high densities, there was a need for continuation of research to try and increase the digestibility of maize silage, because we thought that increases in digestibility would give rise to improvements in rate of live weight gain and reduce the need for additional concentrates. We welcomed very much the effort which is currently going into approaches such as the use of brown midrib mutants for improving the digestibility of maize silage. So, our discussion on digestibility was very much in accord with that of Group A and I believe it complemented their discussions.
On efficiency of energy utilisation, we spent most of our time talking about energy metabolism studies, following on from the paper of Van Es. We know that there are a lot of animal feeding experiments in which we know how much food goes in and how much live weight gain is produced, but we have a very limited ability from these production experiments to determine whether the grain content, starch content and alpha/beta cellulose glucose ratios, are important in affecting the efficiency of energy utilisation with maize. So we gave very strong support to the need for a continuation and expansion of the work on energy value of maize. Van Es is continuing such studies and will be looking at materials of different growth stages. Vermorel in France is also going to be using -maize silage in his energy metabolism work. We thought, although we did not really discuss this in detail that there is a probable need for parallel studies to be undertaken in countries further south in Europe where higher temperatures for growth might have effects on composition and energy. This is one of the two areas to which we have given most priority.
To intake, we gave somewhat less priority in our discussion than we did to efficiency of energy metabolism. The factors
564 mentioned already - digestibility and efficiency of energy use - are, of course, common and important in all feeding systems, whereas we are not always feeding to appetite. We accepted that we could make some prediction of intake from dry matter content of silage. We would put a barrier somewhere at 30% or 35% dry matter, above which we would not expect any further increase in intake. We thought that we could have some standard of intake and dry matter content, but we were in unanimous agreement that there was very much that we needed to do to improve and increase our understanding of factors limiting the consumption of silage. With the increase in dry matter content, as Wilkinson pointed out yesterday, there are a lot of concomitant changes, We accepted an association between acidity and intake but were doubtful as to whether we knew enough' about this physiologically to be able to think very sensibly of how we would alter the way that we make maize silage to improve intake. We need more information to sort out the effects of rumen pH, salivary secretion, physical factors and acid-base balance. We think there is still a strong need for research in that area and once we have made more progress there we will be more optimistic about our ability to make progress in increasing the intake of maize silage.
With regard to protein metabolism or efficiency of nitrogen utilisation, there was some division in that we accepted that the cost of providing appropriate nitrogen supplements to maize silage for beef cattle is much less than is the cost of rectifying nitrogen deficiency in maize silage for dairy cows However, we considered that both with beef animals and with dairy cows, the need was to use maize silage more in quantitive studies of digestion and metabolism in a ruminant animal, quantifying the amount of protein nitrogen which is degraded within the rumen, the levels of rumen ammonia and the efficiency of microbial protein synthesis. There are quite a number of groups throughout Europe and throughout the world who are making progress towards a full understanding of digestion and metabolism of nitrogen components in the rumen. We want them to be using maize silage, and different types of maize silage, in some of their work. In our laboratory in Hurley, we are moving in that direction, there will only be a limited amount of material we
565
would use and I think in France and in Germany there will also be some movement in this direction. We thought that this was what was wanted, rather than the two thousandth experiment on feeding non-protein nitrogen in applied experiments with beef cattle. We think that there are situations where non-protein nitrogen would be used efficiently but we put the highest priority, not on undertaking more production experiments with non-protein nitrogen, but on more effort at a more basic level in terms of nitrogen digestion and metabolism and the use of maize silages in those experiments.
We also discussed protected proteins and felt there was scope with the young calf, as well as with the dairy cow for the effective use of protected protein of maize silage; here we considered both naturally and artificially protected protein supplements, and also the possibility of using additives during ensiling to achieve protection of the protein in the silage. We thought that both approaches would need to be explored now and in the future. If we had been considering a European programme based not solely on a beef programme, but in relation to ruminant animals in general, we would have given a slightly higher piority to protein metabolism.
The final item that we discussed was carcass composition. We recognise that in terms of economic efficiency and in terms of the practicality of feeding systems, the effects of diet and of animal genotype and animal type on carcass composition were of great importance, and we wanted to see more of the production experiments using maize silage or maize grain to end up with a fairly detailed description of the carcasses produced. We were particularly keen that there would be more measurements of carcass composition by dissection or division of at least part of the carcass into fat and protein, so that people throughout Europe would really know carcass composition rather than make subjective assessments.
We thought this was an area which had been considerably neglected. It has been discussed in other EEC working groups particularly with a focus on genotypes of the animal, but we can see the probability of big interactions between type of animal and feeding method, affecting what feeding systems are practical and economic. So, this will gain extremely high
566
priority. We did not have time to discuss the utilisation of maize stover; we very much regret this. We were not, in the time available, able to discuss questions of toxins and disease-infected maize plants and we did not discuss mineral metabolism. That does not mean we decided that these were unimportant.
J.C. Tayler
This is open to discussion.
Ch. V. Boucqué
We do not know enough about protein requirements.
R.J. Wilkins
Yes, I would accept that. We felt that there was a need for fairly detailed study of protein digestion and metabolism which would be of help in defining protein requirements as well as indicating particular maize diets. We had quite a lot of discussion and noted that there was a big variation in standards in different countries and we also noted considerable doubt about the value of some of the non-protein nitrogen in maize silage, the value of some of the water soluble nitrogen fractions - we thought that attention should be paid to these.
B. Cottyn
May I ask for an explanation. I understood that the idea was to measure the digestibility of maize silage supplemented with a concentrate, I think, to reach a protein content of 11%. What level of concentrate supplement do you recommend, because you must make a separate digestion trial with this concentrate mixture alone and that will be difficult?
J.C. Tayler
This is a subject which needs much further discussion than we have time for at the moment. We had a suggestion from both
567
groups about prediction of digestibility and standardisation of methods Of measuring digestibility, both in vitro and in vivo and a working party is evidently required to go into the sort of detail which we cannot discuss now.
F. de Boer
As far as the standardisation of digestion experiments is concerned, I think that there is a report from several years ago in the circles of EAAP which would be worthwhile to look at There might be items which can be utilised without involving any new work.
A second point I want to make is on carcass dissection. Should we not stress the significance of utilising the specific gravity method to predict chemical composition from parts of the carcass instead of dissection which is very time consuming and only gives you information about tissue relations?
J.C. Tayler
The best answer to that is that we have available the Proceedings of the Zeist seminar, which is full of papers and discussion on these techniques and the points you raised very rightly, are fully discussed there. That is probably the right source to go to for further details of methodology which we do not have time to go into now.* Are there any research programmes not in the list in Appendix II?
Ch. V. Boucqué
The list is complete.
* (Criteria and methods for assessment of carcass and meat characteristics in beef production experiments, 1976 A.V. Fisher, J.C. Tayler, H. de Boer and D.H. van Adrickem Boogaert, Editors, Commission of the European Communities, EUR 5489).
568
Κ. G. MgSlle
In co-operation with the State Animal Research Service, we do some investigations on the digestibility of maize harvested at different times. We have tried to compare digestibility in vivo and solubility in vitro.
Y. Geay
We are working on the same ground as has been defined by Dr. Wilkins.
J.C. Tayler
I know Germany has much work listed on these subjects.
J. Harte
I think it is a mistake to say carcass composition is very expensive because it is not very expensive in comparison with the cost of running a trial for two years.
J.C. Tayler
This is a good point that was made several times in Ze±st.
D. Lanari Italy
We are doing something on maize digestibility, trying to find a correlation between sheep and cattle. Perhaps we should only use cattle?
J.C. Tayler
There was a point made by Professor Vetter, returning to standardisation, that we should perhaps include methods of preparation of samples for analysis. This is probably important and something that could be dealt with by the working party already proposed.
569
The lists of research projects on this subject are complete for the Netherlands and the UK? Yes?
B. Laber
We will send in a list. We carry out some experiments with maize grain and urea and also with whole crop maize pellets.
Ms. L. Syrjaia
We have no plans for any work, but I think that a very important point would be animal experiments with urea.
D. Hergounis
We have no work on cattle production, just on lamb, which is concerned with the utilisation of high-protein grain.
A. Monteagudo
Spain is also interested in sheep feeding.
J.C. Tayler
Well although this is a beef conference we cannot exclude an interest in other ruminants in so far as maize is important there.
H. Schneeberger
Our list is complete.
T. Cobic
Our programme is outlined in Appendix II.
R.J. Wilkins
We are very conscious about the lack of discussion on maize
570 stover utilisation. I am not proposing any particular work but remind you of the point which I think most of us accepted earlier, that it is unfortunate if we grow a crop and then leave 40% of the potential energy in the field, so we should be trying to use whole crop maize more in southern Europe. Then we have a lot of maize grain required for non-ruminant nutrition and must really see if we can use stover more effectively. Vetter indicated a considerable potential for using stover or treated and mixed stover, not only in maintenance rations but also in production rations.
D. Lanari
In Italy we know that it will be impossible for us to produce all the beef that we consume, but we are trying to reduce the number of cattle imported. So, since we produce a lot of maize grain, it could be useful to look at the composition of feed in one or two suckler herds of cows.
I have some preliminary results and I now have financial aid from the Italian National Research Council to look at results of the people working on the machinery for this. I am looking at the question of mechanisation and the machinery most suitable and I will try to look at the nutritional aspect of corn stover. I want to run some conservation trials in bunker silos and to look at the digestibility of corn stover.
J.C. Tayler
What about Yugoslavia? Could we have a comment on what they think about their research programme in relation to the utilisation of maize stover. What are your plans and proposals there - you have some interest in them?
T. cObic
At the moment maize stover is neglected here because the technology of harvesting is such that the corn is shelled on the fields and sent directly to the drier and all the stover is completely destroyed. We have no machinery in this country
571 such as they have in the States that we saw on the slides, but perhaps we could do something if we can be supported by somebody to do it. Further, in relation to the utilisation of stover, because we have no beef cattle but only dual purpose and dairy cattle, it is not possible, not economic, to use corn stover for dairy cattle in this country. So we might be interested in using this experimentally if the machinery were available.
J.C. Tayler
Is there any other class of livestock such as growing heifers which might utilise this material with some supplementation? There are possibilities that have not yet been explored?
T. Cobic
There might be. We have this product which is now neglected.
Harte
We are not doing anything different with maize from what we do with cereals. We leave the straw there too and we burn it. Perhaps Professor Vetter would like to comment on that because there is an enormous amount of energy left there too.
R.L. Vetter USA
Yes, I see no reason why we cannot develop' the use of technology on this. We have wheat and barley straw programmes in the States. I see no reason why they cannot be equally as successful as with corn stover. Straw may require more processing than does the corn stover but I think we have inherently more problems with stover than we do with straw.
E. Ζ immer
There· are some problems involved in conserving these materials to get the right amount of water to start fermentation
572 because there is a lack of sugars, to add some urea to improve the material and so on, and also to use the right technology. I do not know whether this justifies a project, because here and there there are already groups working and they will publish their results socn; we heard Professor Vetter, and his findings are already published. So, I am not sure whether it would be a correct conclusion to set up a project.
J.C. Tayler
We need to move on, and ask Dr. Sreckovic if he would give us a report of the group that dealt with systems of beef production, input and output of feed and of animal produce, and economics.
A. Sreckovic Yugoelaoia
Although there were only six of us in our group, I would like to read a summary and, if necessary, ask other members of the group to give an explanation.
Economic aspects cannot be isolated from agronomic and nutritional considerations. There is need to put all the major variables, e.g. type of production, silage or grain,in an economic model to assess their effect with a wide range of cost/price situations.
A simple set of rules, if followed, should produce a consistent result. Information is required on the following topics to enable a model system to be built.
1) Production of maize grain and forage crops, with or without irrigation, with special regard to economic effects. 2) The production of maize as a second crop - utilisation of soil, irrigation system and the utilisation of the crop. 3) Organisation of beef prodcution, based on co-operation between large industrial units and small private farms. 4) Losses of nutrients and dry matter, and change in nutrient concentration, in all forms of maize, depending on the various systems of conservation. 5) Intake as influenced by differences in feed dry matter content, age and live weight of animals. 6) Supplementation of silage with respect to energy and
573
protein content - protein and NPN. 7) Nutrient requirements of animals at different levels of performance, age, live V7eight and breed. This should include, not only average requirements, but an estimate of variation between animals. 8) The carcass composition of animals finished at different rates of gain on different rations. 9) The system of housing beef cattle, organisation of housing - regarding housing conditions, health protection and productivity of work. 10) Different market requirements, and the matching of production systems to these different requirements.
J.C. Tayler
This summary is open to discussion.
E. Zimmer
Should we understand these ten points as a recommendation for planning research activities?
J.C. Tayler
My understanding of this list is that we have ten points, which are rather more than the number of points from the other two groups. From a group which dealt with the whole system of animal nutrition and many other things , they have indicated some of the important weaknesses in their knowledge of putting together systems, which obviously duplicate some of the things found to need further data and research by the other two groups. The findings of the independent groups reinforce what has already been concluded in the other two groups and this is wholly desirable.
R.J. Wilkins
I would endorse the first comment that was made in this report, indicating that there was need, as there is in most
574
countries in fact, to put all major variables in an economic model and assess this under different cost/price situations. This is an exercise that needs to be done by biologists and economists working together, very much more than it has been done in the past and it is very refreshing to have the two papers from Walter and Lelong this morning touching on this. I would be very hesitant in fa'ct, to take that much notice at the moment, of the ten points that you think that you really need to set up a good model. You can set up the biology of it and try all the different assumptions and locate the more sensitive areas, and it is only after that that we would necessarily give strong support to those items that you listed. They all seem on the face of it to be pretty reasonable, but I think that you can make a od progress in some modelling work without having the definiti e evidence.
J. Harte
We had considerable difficulty in deciding what the system was, but we did find there a system - a set of rules. In fact we saw it as if a farmer were wanting to set up a single system of beef production using maize. We would want to keep in mind, of course, what our business is in this whole game- It is to service farmers and to service the industry, and we said that we would want a clear set of rules on which we could do a reasonable job and get consistent results. We were very worried about dipping into other groups' work. For instance, I would not have been able to get a set of rules about the level of nitrogen used. One group said twice as much as the other and the base group was so high that twice as much was a lot higher. So, this was one of our problems and this was what we set out in some of those points.
K. Walter West Germany
I would like to ask the men that make experiments if it is not possible to publish more details. For example, you have production material from cattle weighing 300 - 500 kg and in the publication you say that, on average the animal had a daily intake of about 10 kg, but we do not know the intake at 300 kg and at 500 kg. For economists to make calculations, we must
575 know exactly the intake at all stages up to 500 kg. It is helpful to know that the average consumption is 10 kg, but we cannot do any calculations with this figure.
J.C. Tayler
Are there any points which anyone would like to add to their list? The lists are complete on this subject for Belgium, Denmark, France and Germany. Is more research on mechanisation needed in Germany?
E. Zimmer
I have a list of the research done at Munich and at Kiel regarding questions of mechanisation. I think that it is current for Germany's conditions nov/ and because it »/as not on our programme we did not discuss this, but I would expect that there is a need of more research in depth in technology that would deal with certain conditions of grain size and soil. However, we should need at least two hours to discuss this.
D. Lanari
We feel the need of research on systems and we are doing something in one region.
J.C. Tayler
The Netherlands, UK, Austria is there anything to add?
Β. Laber
There are the same conditions and problems as in Germany.
Ms. L. Syrjaia
The main question in our country is which is more economic, maize silage or grass silage?
576
Α. Monteagudo
Efficiency, water utilisation, irrigation, are important.
T. Cobic
In Yugoslavia, we are still very interested in the systems we listed, but we would like to exclude Item E, on dehydration.
J.C. Tayler
This is because it uses too much energy, in the way we have discussed in earlier sessions?
T. Cobic
It is a general thing that dehydration is out of discussion.
J.C. Tayler
So, your research would be tending to be moving more into whole-crop silage and other aspects of ensiled material?
T. Cobic
Yes.
J.C. Tayler
There seem to be no more comments forthcoming. This seems to be a reflection of the fact that we have had a pretty full discussion time planned into this conference which is good, because to read a lot of papers and to have no opportunity to discuss them is not the best way to get together. So, it seems that the format has been successful to that degree, and it is time to wind things up. The time has passed for trying to summarise, because the last session itself has been a summary. First of all, in Session I we had a survey of the situation in each country, where we looked at not only maize
577 grain used for non-ruminants and ruminants but also the whole crop. We found that, for example, forage maize is increasing very rapidly in area in many countries. Yields are tending to increase and altogether there is a search for higher output per ha. This pushes one into forage maize with maximum utilisation or, if you do take the grain, into trying to achieve maximum utilisation, in other ways, of the various parts of the plant.
We went through nutritional aspects. We found stress, as is to be expected, on the nitrogen content of maize, which is low, and on means of putting this right most effectively, perhaps by protecting protein. We have certainly drawn some valuable lessons from our discussions there. We have just been through three lists which indicate what further research is needed and we know that this represents what we need to know in future, and where the gaps are, which need further research. One important point is that still we find, going back to the initial session that.as much as 50% of concentrate is still being fed in some of the diets, to beef cattle, and quite evidently there is considerable pressure to reduce this. However, we need to know more about how to make maize silage itself acceptable, to obtain adequately high rates of live weight gain, to produce suitable carcass composition in the various breeds of livestock. The only way to get this sort of information is by research and I think the results of our last three sessions have shown the very considerable value of an interchange of information. In many of the discussion sessions we found that people in one part of Europe were not entirely aware of the advances that have been made recently in other parts. We clarified some of the differences that occur between different climatic regions, such as the southern ones -the need for irrigation, problems of high temperatures: the central regions where they have a wide range of conditions, and the more northern ones where we are getting even into a marginal situation in terms of whether you can grow maize at all and selection of new varieties is needed. This has been a very wide-ranging consideration over 19 countries. It has astonished me how great a degree of agreement we have been able to get over particular problems that are common to everybody, and yet
578 at the same time we have highlighted some of the differences due to climatic regions where perhaps the emphasis of research would obviously need to be different.
This conference has therefore been one which has quite obviously demonstrated the importance of the interchange of information and co-ordination in every possible form between those working on a particular topic, meeting each other, understanding what their problems are, standardising techniques and so on. There are a few points for the future that might emerge - in particular we might consider asking the Commission to support a working party on some aspects of the work that we discussed. The most obvious one, which emerged in two of the sessions, was that of standardising digestibility assessment and the prediction of nutritive value in general from laboratory methods and the whole problem of relationships between the measurements that the breeder can make and animal performance, which is the end of the whole process. Of course there are also the difficulties that the breeder has in knowing whether the measurements that he is making are giving the right predictions in terms of animal performance. It is very expensive to carry out animal production experiments and this is why there is such a lack of data on those aspects.
This has been a vast programme with a wide range of countries and subjects. There are several things left to do. One of them is to thank you all for your discussion and for your discipline in going into these three groups and producing your reports. I would like to thank you for this session and finally to ask Mr. Craps if he would help us bring the discussion to a close: Mr. Raymond Craps, Director of Agricultural Structures and the Environment, from Brussels.
R. Craps EEC
It is always pleasant when one can close such a conference, and I would like to thank every one of you for being instrumental in making this conference a success. I would like first of all very ardently to say also, in your name, a very great 'thank you' to our Yugoslav friends because they had more than one role here. They had to organise, they had to make us happy
579 first and then to keep us happy and at the same time they did contribute in a very important way to the scientific value of these discussions, therefore many, many thanks to them. Many thanks also to all those who, either as chairmen of sessions or discussion groups, as reporters, or as participants, have been very actively intervening and animating the discussions. Mr. Chairman, I would really like to thank you very much. Vie know that you are very discreet, we know that you are very active and very efficient and I am very glad that we could rely on your co-operation to organise the scientific part of this meeting and as I said, to bring it to the point where we are now.
A conference is only half starting when it is finishing: it is extremely important for bringing people together -having this exchange of information - having stocktaking of the state of research and the expected research to come. However, in this particular case we have to look towards the future: we have to look further than that, further than a cliché, we have to try and devise a kind of a blue print for the future. I listened to the last session and heard quite a number of points being made - estimations, experiments, standardisation, working parties. It is from that side that I would like to pick up this end of the conference, looking at what results and conclusions can be drawn from it.
You know that this conference was being held in the framework of COST and at the same time within the prospects of co-ordinated work in the framework of an existing programme of the Community on beef production. I can say that we certainly are going to take back all these data and all these suggestions and report both to COST and to the standing committee on Agricultural Research, and to the Commission. Certainly one comes to the conclusion, even after -only listening this afternoon, that notwithstanding the level already reached by research in many countries, here is a field for useful further co-ordination. Taking into account the needs and the responsibilities of participants here, we should, on the Community side, aim for concerted action to make progress in that sense.
580
Another conclusion which struck me when I was listening is that again we have found confirmation that whenever a body like the Community, or other important international organisations or agencies is considering entering a new field of research to co-ordinate it, it cannot restrict itself to looking within its own territory. It must, right from the start, look outside and take stock of what exists there and find out and draw conclusions about the extent of the coordination which has to be either inside the problem or around the problem but must be widely supported and will then improve the chances of success. These, Mr. Chairman, are at least two main positive recommendations which I personally can tell you, I will certainly make at Community level, basing them as I said on the success of this conference and I would like to ask you - all of you - to make one final contribution. It would be important if, in returning home you yourselves would report to those who, in your country, because of their position in research policy and management, are representing your country either in COST or in CPRA, on what this meeting has achieved because this certainly is going to play an important role in the chances of furthering the efforts which have been launched here over these last three days.
I would like to close here because I am impressed by this efficiency drive which has been governing all your work in the last three days. It certainly was a working conference, I think never has a wording been so appropriate for a conference as now, but I am very happy to see that you have all survived it and still remain in the best spirits. You might have wondered why we, from the Commission, did not intervene. I think that it was very right. First of all we are only laymen in research and secondly you never - I was going to say "change a winning team1.' - you never intervene when things are going very well, so thank you very much all of you. I would like to close this conference and remind you that we expect to see you all tonight to finish this conference in a friendly way and that we might also see each other tomorrow in the sightseeing trip. Thank you, all of you, very much indeed.
Animal Feed Science and Technology. 1 (1976) 581-602 581 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
APPENDIX I
Countries of the COST group with participants at the conference, and names of representatives who provided information on researoh activity in their countries in the form indicated in Appendix II.
Community countries
til (ii) Ciii) tiv) (ν) (vi) [vii)
Belgium Denmark France Germany (Fed. Rep.) Ireland Italy The Netherlands
(viii) United Kingdom
Representative
F.X. Buysse K.G. Mølle Y. Geay E. Zimmer F.J. Harte D. Lanari F. de Boer J.M. Wilkinson
Third countries
(ix) Austria (x) Finland (xi) Greece (xii) Portugal (xiii) Spain (xiv) Switzerland (xv) Yugoslavia
Representative
B. Laber L. Syrjaia D. Mergounis J.S. Da Costa G. Gonzalez H. Schneeberger T. Cobic
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APPENDIX II
PROJECTS BEING CONDUCTED AND PLANNED
Information on Research Institutes and other organisations conducting research on the maize crop for ruminants, collated by the representatives listed in Appendix I.
584
(i) BELGIUM
Address
National Institute for Animal Nutrition, Scheideweg 12, B-9231 Gontrode, Belgium. Director: F.X. Buysse
Project
Study of different non-protein nitrogen sources in dough-dent maize silage Rumipec (50 urea/50 minerals) Pro-sil (MH3 and minerals suspended in molasses)
Research staff
Influence on conservation processes [quantitative and qualitative criteria) Influence on beef bull production results (animal performance) Influence on digestibility in vivo (wethers)
B.G. Cottyn Ch. V. Boucqué
Ch. V. Boucqué B.G. Cottyn
B.G. Cottyn J.V. Aerts
Study of daugh-dent maize silage infected by corn smut fungi [Ustilago mayáis)
Influence on young bull performance Influence on digestibility in vivo
Ch. V. Boucque B.G. Cottyn B.G. Cottyn J.V. Aerts
Influence of the stage of maturity of the maize plant on: yield per ha chemical and morphological composition in vivo digestibility (wethers and dairy cows)
J.V. Aerts B.G. Cottyn Ch. V. Boucqué
Faculte de Médecine Vétérinaire de l'Université de Liège Chaire de Zootechnie Prof. Dr. E. Cordiez
Rue des Vétérinaires 45, 1070 Cureghem, Bruxelles.
Optimum level of energy E. Cordiez supplementation of rations 0. Lambot based on maize silage for J. Bienfait beef production Optimum level of protein E. Cordiez supplementation of rations 0. Lambot based on maize silage for J. Bienfait beef production Utilisation of maize ear E. Cordiez silage for young beef bull 0. Lambot production J. Bienfait
(ii) DENMARK
585
Address
Statens Forsøgsstation, Askov, DK 6600 Vejen.
Project
Placement of nitrogen and phosphorus for silage maize
Research staff
A. Dam Kofoed
Statens Frøavlsog Industriplanteforsøg, Langelinje 6 B, DK 5000 Odense.
Maize cultivars for silage Plant density, row distance and nitrogen level in maize
Asger Larsen
Statens Forsøgsstation, Ledreborg Allé 100, DK 4000 Roskilde.
Maize compared to sunflower as forage crops
Poul Rasmussen
Statens Forsøgsstation, Ødum, DK Θ370 Hadsten.
Additives and techniques of ensiling maize
Kr. G. Mølle
Digestibility of maize at different developmental stages
Statens Ukrudtsforsøg, Flakkebjerg, DK 4200 Slagelse.
Weed control in maize Søren Thorup
Statens Forsøgsstation, DK 6360 Tinglev.
Irrigation of maize Hardy Knudsen
Landsudvalget for Planteavl, Kongsgárdsvej 28, OK 8260 Viby J.
Maize for stall feeding
Maize cultivars for silage and stall feeding
Johannes Olesen
Plant density in maize
Placement of phosphorus for silage maize
Weed control in silage maize
586 (iii) FRANCE
Address
Station d'Economie de l'Elevage, INRA, Theix, 63110 Beaumont.
Project
Economie value of various forms of maize in the feeding of young bulls Utilisation of maize silage by lactating dairy cows Factors affecting the nutritive value of maize silage Utilisation of energy and protein by young bulls of different breeds given maize silage diets
Research stoff
G. Lienard
η. Journet R. Vérité C. Demarquilly J. Andrieu
M. Vermorel Y. Geay
Station Centrale de Génétique et d'Amélioration des Plantes, INRA-CNRA, 76000 Versailles.
Breeding of grain ΓΊ. Derieux
Station d'Amélioration des Plantes, INRA, 34000 Montpellier.
Breeding and agronomic evaluation of improved varieties of maize grain
A. Cotte Ξ. Rautou
Station d'Amélioration des Plantes, INRA, 35000 Rennes.
Breeding and agronomie evaluation of improved varieties of maize grain
Barloy
Station d'Amélioration des Plantes, INRA-CRA, B3000 Clermont-Ferrand.
Breeding and agronomic evaluation of improved varieties of maize grain
n. Pollacsek PI. Caenen
Station d'Amélioration des Plantes, Lusignon.
Breeding of improved varieties of forage maize and in vitro nutritive value Utilisation of different varieties of maize forage by young bulls
A. Galláis
C. Malterre L. Huguet G. Bertin
Laboratoire de Recherches Utilisation of maize by sur la Conservation et monogastrics and ruminants l'Efficacité des Aliments, INRA-CNRZ, 76350 Jouy-en-Josas.
M. Delort-Laval
Station de Biochimie et de Physicochimie des Céréales et de leurs Dérivés, INRA, Le Noyer-Lambert, 91300 Nassy.
Evolution of biochemical characteristics of maize grain during processing
B. Godon L. Petit
Address Project
Station d'Economie RuralG Place of maize in farming uiJSA, 35000 Rennes. systems
S87
Research staff
R. Hovelaque Cordonnier
Laboratoire d'Economie Rurale, ENSSAA. BP 58Θ. 21U00 Dijon.
CNEEMA (Centre National d'étude et d'expérimentation de machinisme agricole)
Place of the maize crop in production systems on arable farms
Methods of conservation of maize grain
G. Lienard Π. Petit P. de la Vaissère J. Brossier Le Du
AGPM, Pau.
ITCF, Station Expérimentale, Boignevills.
ITEB, Paris.
Factors affecting the growing of maize forage and grain
Conservation of maize grain and forage: recording of maize silage on farms Utilisation of the maize plant for bull beef production
Utilisation of maize silage by dairy cattle Utilisation of maize silage by beef cattle
Raillard D. Bloc Soffiet Lasseran Mosnier, Cornet C. Lelong de Pous
Girard, Pfimlin Cadot, Dubis, Haurez Mourier
Service d'Expérimentation Agronomic evaluation of INRA, La Minière, improved varieties of maize 78000 Versailles. grain
L. Felix
(iv) FEDERAL REPUBLIC OF GERMANY
Address and research staff responsible
Institut f'Jr Milcherzeugung der Bundesanstalt für Milchforschung, HermannWeigmann Str. 127, 2300 Kiel. Prof. Dr. W. Kaufmann
Project
Additives NPN, use and utilisation Feeding ruminants
Institut für Landwirtschaftliche Verfahrenstechnik der Universität Kiel, Olshausenstr. 4060, 2300 Kiel Prof. Dr. U. Riemann
Technology, grain Feeding technique Conservation technique
588
Address and research staff responsible Project
Nutritive value Institut für Tierernährung der Feeding technique Forschungsanstalt für Landwirtschaft Bundesallee 50, 3300 Braunschweig. Prof. Dr. H.J. Oslage NPN, use and utilisation Prof. Dr. K. Rohr
Feeding pigs Quality aspects of new varieties
Conservation losses Institut für Grünlandwirtschaft, Conservation technique Futterbau und Futterkonserv der Forschungsanstalt fur Landwirtschaft, Bundesallee 50, 3300 Braunschweig. Additives Prof. Dr. E. Zimmer Wor. Dr. H. Honig Nutritive value
Quality aspects of new varieties
Bayerische Landesanstalt fur Conservation technique Tierzucht, Prof. OUrrwaechterPlatz 1, 8011 Grub Post Poing b. München. Reg. Dir. Dr. F. Gros Additives
Conservation losses
Nutritive value Quality aspects of new varieties
Institut fur Landtechnik der Technology, grain Technischen Universität München und Bayer, Landesanstalt für Landtechnik, Techn
°l°gy silage Vöttingerstr. 3B, B050 Freising Feeding technique Weihenstephan. Prof. Dr. H.L. Venner Dr. M. Estler
Lehrstuhl för Wirtschaftslehre des Economics Landbaues der Technischen Universität München, Θ050 FreisingWeistenstephan. Prof. Dr. H. Steinhauser
Abteilung Pflanzenzüchtung II der Quality aspects of new varieties Universität Hohenheim (LH), Garbenstr. 9, 7000 Stuttgart 70. Prof. Dr. W.G. Polimer
Cv) IRELAND
589
Address Project*
Agricultural Institute, Fertiliser requirements Johnstown Castle, Wexford, of maize
Agricultural Institute, Oakpark, Carlow.
Methods of sowing maize
Weed control methods Problems of bird control in maize production Evaluation of maize varieties Evaluation of open-pollinated tropical maize Maize harvesting machinery
Research staff
M. Ryan
B. Rice
B.J. Mitchel Ρ. Comerford M. Neenan M. Neenan J. Deveraux
B.S. Ahloowalia
P. Comerford Agricultural Institute, Oakpark, Carlow, and Dunsinea, Castleknock, Co. Dublin.
Factors affecting the quality of maize silage
T.A. Spillane J. D'Shea M. Neenan
Agricultural Institute, Oakpark, Carlow, and Agricultural Institute, Grange, Ounsany, Co. Meath.
Feeding maize silage to beef cattle
V. Flynn M. Neenan J. O'Shea Τ. Leonard
Projects completed or almost completed
(vi) ITALY
Address
Istituto Oi Agronomia, Via Filippo Re Ν.6, Bologna.
Project
Maize breeding Maize cultivation
Research staff
S. Conti G. Toderi
Istituto Produzione Foraggere, Via Fillipo Re 8, Bologna.
Maize cultivation Maize conservation
A. Giardini
Centro Conservazione Foraggi, Via Filippo Re 8, Bologna.
Maize cultivation Maize conservation Additives Animal feeding
A. Giardini
590
Address Project
Istituto Di Miglioramento Maize breeding Genetias, Perugia.
Istituto Di Agronomia, Perugia.
Centro Germoplasma, Istituto Di Maiscoltura, Bergamo.
Maize breeding Maize cultivation
Maize breeding
Research staff
A, Panella
F. Bonciarelli
Porceddu
Istituto Di Agronomia, Milan.
Maize cultivation Bellini
Istituto Di Agronomia, Via Celso Ulpiani, Bari.
Maize cultivation F. Lanza Marzi
Istituto Di Nutrizione Animale, Piacenza.
Istituto Di Zootecnica Via Gradenigo 6, Padova.
Istituto Di Zootecnica, Turin.
Maize conservation Animal feeding
Maize conservation Additives Animal feeding
Additives Animal feeding
Maize conservation Animal feeding
Maize cultivation
Animal feeding
G. Piva
R. Parigi-Bini
D. Lanari
G.M. Chiericato
L. Toniolo
A. Bosticco
Istituto per la Cerealicoltura, Rome.
Maize cultivation Mariani
Istituto Sperimentale per la Zootecnia, Via Panvinio 11., Rome.
Maize conservation Additives Animal feeding
F. Malossini
(vii) THE NETHERLANDS
591
Address
Oept. of Field Crops and Grassland Husbandry, Agrie. University, Haarweg 33, Wageningen.
Project
Effect of light intensity and temperature on production and feeding value of maize
Research staff
Research Station for Arable Farming, Edelhertweg 1, Lelystad.
Fertiliser levels (Ν,Ρ,Βο) in maize growing Comparison of continuous maize growing with a growing system alternating maize and sugarbeets Combined growing of maize and soya beans. (In co-operation with Research Station No.3)
Research and Advisory Station for Cattle Husbandry, Runderweg 6, Lelystad.
Ratio of maize silage and wilted grass silage in dairy cattle rations Application of conservation additives in maize silage maKing and utilisation of such silage in dairy cattle feeding
Institute for Livestock Feeding and Nutrition Research "Hoorn", Runderweg 2, Lelystad.
Research on feeding value of maize silage in digestibility, energy balance trials and in group feeding experiments
(viii) UNITED KINGDOM
Address
The Grassland Research Institute, Hurley, Maidenhead, Berks.
Project
Utilisation of maize silage for beef cattle Utilisation of maize silage by lactating cows Utilisation of energy and protein by calves given diets containing maize silage Factors affecting the nutritive value of maize Agronomic and in vitro nutritive evaluation of forage maize
Research staff
J.C. Tayler
J.C. Tayler K. Aston D.F. Osbourn B.R. Cottrill
J.M. Wilkinson
R.D. Sheldrick
592
Address
National Institute for Research in Dairying, Shinfield, Reading, Berks.
Project
Utilisation of maize silage by heifer calves Agronomic evaluation of forage maize and its utilisation by lactating cows
Research staff
J.D. Leaver
R.H. Phipp5
Meat and Livestock Commission, Bletchley, Bucks.
Recording of the use of maize silage on commercial beef farms
J.B. Kilkenny
Mil Κ Marketing Board, Thames Ditton, Surrey.
Recording of the use of maize silage on commercial dairy farms
J.A. Craven
Plant Breeding Institute, Cambridge.
Breeding and agronomic R.E. Gunn evaluation of improved ^ E.S. Bunting varieties of forage maize
Ministry of Agriculture, Agricultural Development and Advisory Service.
Analysis of the composition of maize silages made on farms Use of maize silage on commercial farms
G. Alderman C. Fairbairn B. Shingler B. Shingler D. Thompson C. Fairbairn
Boxworth EHF, Cambridgeshire.
National Institute of Agricultural Botany
Protein levels for beef and dairy production Agronomy of maize production
Evaluation of forage maize varieties
P. Bowerman
P. Bowerman
D.S. Kimber
University of London (Wye College!
Agronomy of forage and grain maize
G. Milbourn
University of Nottingham
Nutritive value of dehydrated whole crop maize
Swan
(ix) AUSTRIA
593
Address
Bundesanstalt för Pflanzenbau und Samenprüfung, Alliiertenstrasse 1, A-1020 Vienna II.
Project
Trials with different varieties of maize
Institut für Lantechnik und Energiewirtschaft, Universität für Bodenkultur, Peter Jordanstrasse 82, A-1190 Vienna XIX.
Methods for drying maize grain
Bundesversuchswirtschaften des Bundesministeriums für Land und Forstwirtschaft, Stubenring 1-3, A-1010 Vienna I.
Trials with dehydrated whole-crop maize pellets and trials with urea in maize diets
[x) FINLAND
Address
Finnish Maize Committee:
University of Helsinki, 00710 Helsinki Department of Plant Husbandry Department of Plant Breeding Department of Animal Husbandry
Department of Plant Husbandry, Agricultural Research Centre, PIO 18, 01301 Vantaa 30.
Farm Machine Research Institute, Vakola» Helsinki 100.
Mr. G. Bröninghaus, Halikko.
Project
Possibility of growing maize in Finland
Research staff
S. Pulii
P.M.A. Tigerstedt
E. Poutiainen
J. Mukula
A. Reinikainen
594
[xi) GREECE
Address Project
Research Institute for Fattening of lambs with maize Animal Feeding, Giannitsa of high protein content (14%) Dr. D. Mevgounis compared with: ta) cotton
seed oil meal, (b) soya bean oil meal Fattening pigs with maize of high protein content compared with normal maize Estimation of the feeding value of maize with a very high protein content during the fattening period of piglets
Research staff
D. Valamotis
D. Valamotis
D. Valamotis
Cxii) PORTUGAL
Address
Estação de Plelhoramento de Plantas, Estrada Gil Vaz, Elvas.
Project
Self fertilisation of 1 and 2 year old maize to obtain hybrid lines Comparative assays of production of hybrids proceeding from "top cross"
Research staff
J.B. Guerra
Lab. de Estudos de Nutrição Animal, Tapada da Ajuda, Lisbon 3.
Performance of animals when using harvested feed New feeds for meat and milk production
J.P. de Azevedo
Estação Agrária de Braga Lamaçaes, Braga.
Improvement of the maize plant.
S.E. Rego
Estação Zootecnica Nacional Fonta, Boa, Vale de Santarém
Study of nutritive value af crops and their by-products Study of nutritive value of silage maize
Vaz Portugal
(xiii) SPAIN
595
Address
Estación Experimental del Zaidin, (CSIC), Prof. Albareda 1, Granada.
Project
Mineral nutrition of maize crop
Research staff
L. Recalde
Centro de Investigaciones Antropológicas y Genéticas, (CSIC), Barcelona 14.
Maize crop fractionation for the most efficient application of different components for the nutrition of ruminants and nonruminants Production of maize hybrids with high sugar in the stalk at grain maturity and grain high in essential amino acids
A. Pons Calvet J.L. Blanco
Delegación de Agricultura de Zaragoza.
Maize hybrids M. Angulo
Centro Regional del Noroeste, INIA, Apartado No. 10, La Coruna.
Beef and dairy cattle feeding V. Yepes
(xiv) SWITZERLAND '
Address
Swiss Federal Research Station for Animal Production Grangeneuve, CH1725 Posieux.
Project
Utilisation of different Ν sources as supplements to maize silage for beef cattle
Effects of maize silage on the mineral metabolism of cattle Factors affecting the nutritive value of maize silage during conservation
Research staff
F. Jans (Cattle section) R. Daccord (Section of physiology) R. Daccord (Section of physiology)
E. Gallasz (Section of feed conservation)
5%
(xv) YUbOSLAVIA
Address Project Research staff
Poljoprivredni fakultet Production of beef using Oour Institut za rations with the dominant Stočarstvo, Veljka role of maize silage, maize Vlahovica 2, ear and maize grain: 21000 Novi Sad.
Comparison of pure breeds of cattle with crosses for the production of meat Effect of final weight of fattening bulls on live weight gains, feed conversion and production of meat Effect of different ratios S. Bacvanski of maize silage and maize- M. Milosevic based concentrate mixtures in the fattening of young bulls Efficiency of supplementing PI. Kosanovic maize silage with NPN in I. Sibalic order to improve nutritive value of silage for the production of meat
T. s. s. n.
Cobic Vucetic
Bačvanski Milosevic
APPENDIX III
LIST OF PARTICIPANTS
597
Dr. P.E. Andersen National Institute of Animal Research, Rolighedsvej, 25, 195B COPENHAGEN V Denmark
Dr. Refsgaard Andersen Landøkonomisk Forsøgslaboratorium, Rolighedsvej, 25, 195Θ COPENHAGEN V Denmark
Mr. J. Andrieu
Dr. S. Bačvanski
Dr. J.L. Blanco
Mr. Ch. V. Bouqué
Mr. M. Chenost
Dr. G.M. Chiericato
Mr. T. Cobic
Institut National de la Recherche Agronomique,
C.R.Z.V. de Theix, 63110 BEAUMONT France
Institut za stocarstvo. Maksima Gorkog, 26, NOVI SAD Yugoslavia
Departamento de Investigaciones Antropologicas y Genéticas,
Avda. del Generalissimo s/n, BARCELONA 14 Spain
Station d'Alimentation du Bétail, Scheideweg, 12, 9231 GONTRODE Belgium
Animal Nutrition Officer, Animal Production and Health Division,
FAO, Via delle Terme di Caracalla, 1 00100 ROME Italy
Università di Padova, Istituto di Zootecnica» Via Gradenigo, 6, PADOVA Italy
Institut za stocarstvo. Livestock Research Institute, Maksima Gorkog, 26, 21000 NOVI SAD Yugoslavia
598
Mr. Β.G. Cottyn
Mr. R. Craps
Dr. F. de Boer
Or. J.S.P. Da Costa
Mr. Y. Geay
Prof. A. Giardini
Mr. S.E.W. Hallam
Dr. J. Harte
Dr. H. Hönig
Dr. W. Kaufmann
Station d'Alimentation du Bétail, Scheideweg, 12, 9231 GQNTRODE Belgium
Directeur, Commission des Communautés Européenes VIE4 200, rue de la Loi, 1049 BRUSSELS Belgium
Research Institute for Animal Nutrition, Postbus 67, Keern 33, HOORN The Netherlands
Estaco Zootechnica Nacional, Fonte Boa, Vale de Santarem, SANTARÉM Portugal
Laboratoire de la Production de Viande, C.R.Z.V. de Theix, 63110 BEAUMONT France
Istituto di Agronomia Sperimentale e Coltivazioni Erbace,
Via Filippo Re 8, 40100 BOLOGNA Italy
Janssen Services, 14, The Quay, Lower Thames Street, LONDON EC3 UK.
The Agricultural Institute, An Foras Taluntais, Dunsinea Research Centre, CASTLEKNOCK, Co Dublin Ireland
Forschungsanstalt für Landwirtschaft Braunschweig,
3300 BRAUNSCHWEIG Bundesallee, 50, West Germany
Bundesanstalt für Milchforschung, Institut für Milcherzugung, 23 KIEL Hermann Weigmann Strasse, 3 11, West Germany
599
Mr. J.B. Kilkenny Meat and Livestock Commission, PO Box 44, Queensway Mouse, BLETCHLEY - MILTON KEYNES MK2 2EF UK
Mr. J. Kuyl
Dr. B. Laber
Commission des Communautés Européenes, VI - E - 4, 200 rue de la Loi, 1049 - BRUSSELS Belgium
Niederösterreichische Landes, Landwirtschaftskammer, Löweistrasse, 16, 1014 VIENNA Austria
Dr. D. Lanari
Mr. C. Lelong
Università di Padova, Istituto di Zootecnica, Via Gradenigo, 6, PADOVA Italy
Institut Technique des Céréales et des Fourrages,
8, Avenue du Président Wilson, 75116 PARIS France
Mr. L.D.M Mackenzie Chef de Division, Commission des Communautés Européenes VI - E - 4. 200, rue de la Loi, 1049 - BRUSSELS Belgium
Dr. D. Mergounis Station of Agricultural Researches and Cattle Breeding,
lera Odos, 86, Botanic Garden, ATHENS 301 Greece
Dr. K.G. Mølle Ødum Research Station, 8370 - HADSTEN Denmark
Dr. A. Monteagudo Department of Cereals, INIA FINCA ELENCIN, Box 127, Alcalá de Henares, MADRID Spain
600
Ir. D. Oostendorp
Prof. R. Parigi-Bini
Mr. R.H. Phipps
Lic. A. Pons
Mrs. Ν. Rajcan
Mrs N.J. Robins
Prof. A. Romita
Mr. P.P. Rotondo
Dr. R. Savić
Dr. H. Schneeberger
Research and Advisory Institute for Cattle Husbandry,
Runderweg, 6, LELYSTAD The Netherlands
Università di Padova, Istituto di Zootecnica, Via Gradenigo, 6, 35100 PADOVA Italy
National Institute for Research in Dairying,
Shinfield, READING RG2 9AT UK
Departamento Investigaciones Anthro-pplógicas y Genéticas,
Avda. del Generalissimo, BARCELONA - 14 Spain
Sekretarijat za polijoprivredu, NOVI SAD Yugoslavia
Janssen Services, 14, The Quay, Lower Thames Street, LONDON EC3 UK
Istituto Sperimentale per la Zootecnica di Roma,
Via 0. Panvinio, 11, 00162 - RONE Italy
DG. XIII - A - 3, European Center Kirchberg, LUXEMBOURG Luxembourg
Institut za poljoprivredna istrazivanja. Maksima Gorkig, 30, 21000 NOVI SAD Yugoslavia
Directeur de la Station de Recherches s/la Production Animale,
1725 - GRANGENEUVE Switzerland
601 Dr. A. Sreckovic
Ir. Α. Steg
Institut za stocarstvo. Livestock Research Institute, Maksima Gorkog, 26, 21 ODO NOVI SAD Yugoslavia
IWO Runderweg, 2, LELYSTAD, The Netherlands
Dr. Z.Stojanovic
llr. M.J. Strickland
Poljoprivredna fakultet, Institut za stocarstvo, NOVI SAD Yugoslavia
Boxworth Experimental Husbandry Farm, Boxworth, CAMBRIOGE CB3 8NN UK
Ms. L. Syrjälä Department of Animal Husbandry, University of Helsinki, 00710 HELSINKI 71 Finland
Dr. J.C. Tayler The Grassland Research Institute, Hurley, MAIDENHEAD, Berkshire SL6 5LR UK
Prof. R.L. Vetter Department of Animal Science, 301 Kildee Hall, Iowa State University, AMES Iowa 50010 USA
Dr. K. Walter Technische Universität Mönchen, Lehrstuhl für Wirtschaftslehre des
Landbaues, Θ050 FREISING WEIHENSTEPHAN West Germany
Dr. R.J. Wilkins The Grassland Research Institute, Hurley, MAIDENHEAD Berkshire SLB 5LR UK
Dr. J.M. Wilkinson The Grassland Research Institute, Hurley, MAIDENHEAD Berkshire SL6 5LR UK
602
Dr. E. Zimmer
Prof. H. Zlatic
Hr. J. Zscheischler
Forschungsanstalt für Landwirtschaft -Braunschweig,
33D0 BRAUNSCHWEIG Bundesallee, 50, West Germany
Poljoprivredni fakultet, 11000 ZAGREB Simunska, 25, Yugoslavia
Bayerische Landesanstalt für Bodenkultur und Pflanzenbau,
8050 - FREISING - WEIHENSTEPHAN West Germany
FERTILIZERS, CROP QUALITY AND ECONOMY Proceedings of a study week on the use of fertilizers and their effect on increasing crop yield, with particular attention to quality and economy. Pontifical Academy of Sciences, Vatican City, April 1016, 1972.
edited by V. HERNANDO FERNANDEZ, Institute of Soil Science and Plant Biology, Madrid, Spain.
1974. 1468 pages. US $ 86.50 / Dfl. 225.00. ISBN 0444412778
Great concern about the famine which harasses large parts of the world led the Pontifical Academy of Sciences 1972 to hold a study week on fertilizer use. The information contributed by 27 eminent research workers is now available in book form. It deals with soil and plant analysis, fertilizer use in areas with different climatic conditions, ecology, effects of fertilizers on quality of yield, new fertilizers and their prospects, and calculations and methods in determining fertilizer requirements.
CONTENTS: Proper soil fertility evaluation as an important key to increasing crop yields. Optimum economic quantity of fertilizer based on plant tissue composition. Sap analysis as a fertilization index in several types of plants. Correct use of fertilizers in the humid tropics and subtropics and its effect on: I. Plant resistance to diseases II. Crop productivity. Problems of fertilizer use in Latin America. The role of fertilizers in African agriculture. Principles and practice of fertilizer usage in the semiarid to subhumid areas of the Republic of South Africa. The effective use of fertilizers under temperate conditions. An Irish case study. FAO's efforts to increase food production by promoting fertilizer use. Fertilizer use and ecological factors. Profitability and optimal use of mineral fertilizers in farms of different cropping potential. Adjusting fertilizer rates to soil fertility level on the basis of soil testing. Effect of the completely equilibrated fertilizer on the production of plants cultivated on a large scale. The importance of "balanced fertilizers" with 12 mineral nutrients for higher yields of adequate quality. The effects of sulphur, magnesium and sodium on yield and quality of agricultural crops. Mineral fertilization and quality of the crops. Effect of fertilizers on yields and crop quality. Soil fertility and fertilization of cultivated plants. The liquid fertilizer. Fertilizers. The limiting factor in the success or failure of the green revolution. New fertilizers, their agricultural and economic importance. The place of soil fertility and land resources in the future of agricultural production. Crop yield response equations and economic levels of fertilizer use. The derivation of fertilizer recommendations for crops in a nonuniform environment. The effect of cultural practices on efficiency of fertilizer use determined by direct measurement in field experiments using isotopically labelled fertilizers. The fate of organic manures in soil as traced by means of radiocarbon. Chemical fertilizers and crop quality. A hundred years of increasing crops thanks to the use of commercial fertilizers. A retrospective view of the year 1900 and an outlook on the year 2000.
Elsevier P.O. BOX 211 AMSTERDAM, THE NETHERLANDS 14ββ E
AGROECOSYSTEMS An International Journal sponsored by the International Association for Ecology. Editorinchief: JOHN L. HARPER, School of Plant Biology, University College of North Wales, Bangor, G.B. Associate Editor: P. GRUYS, Lienden, The Netherlands.
Subscription information: 1976 Vol. 3 (in 4 issues) US $39.95/Dfl. 100.00 including postage
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