Farm Guidelines for Mastitis Control

Countdown Downunder:

Farm Guidelinesfor Mastitis Control

Pauline BrightlingGraeme A. MeinJakob MalmoDiane P. Ryan

Countdown Downunder: Farm Guidelines for Mastitis Control

ISBN 0 642 37362 0

© Dairy Research and Development Corporation 1998

Australian Mastitis Advisory Council was initiated by the Dairy Research and Development Corporation and has as its key

stakeholders all those dairy organisations with a professional interest in udder health and disease prevention.

If you wish to reproduce the information contained in this document, contact the Project Leader, Dr Pauline Brightling, or the DRDC

Manager Communication, Rob Morton.

The information and guidelines set out in this publication were compiled and developed by the Australian Mastitis Advisory Council,

an unincorporated association funded by the Dairy Research and Development Corporation. The Dairy Research and Development

Corporation and the member organisations of the Australian Mastitis Advisory Council believe that the information and guidelines

contained in this publication are accurate and reliable at the time of going to press. However no warranty of accuracy or reliability of

the information and guidelines is given, and no responsibility for loss arising in any way from or in connection with errors or

omissions in any information or advice or use of the guidelines is accepted by Dairy Research and Development Corporation, the

member organisations of the Australian Mastitis Advisory Council, their employees or consultants.

Publisher: Dairy Research and Development Corporation

Cartoons: Graeme Shephard of Shep Graphics

Cover design: Watson Design

Photos: John O’Flaherty, Pauline Brightling, Graeme Mein and Jakob Malmo

Design & layout: TRENDS in training, a unit of South West Institute of TAFE

Prepress: Substitution

The cover photo shows Karen Baum, technical officer, Agriculture Victoria, Ellinbank.

Countdown Downunder inquiries:

Dr Pauline Brightling

Project Leader

Dairy Research and Development Corporation

3rd Floor, 84 William Street

Melbourne 3000, Australia

Ph: +61 3 9602 5300

Fax: +61 3 9602 5442

Milk quality is an essential element of the Australian dairy industry’scompetitive edge. The industry aims for a ‘clean, green and healthy’image for milk, and udder health is a key component.

The European Union now requires milk and milk products for humanconsumption to have a cell count of less than 400 000 cells/mL and thissets an international benchmark for all dairy exports. Cell count statusmay be a significant factor in limiting access to some export markets.

Mastitis is also important because clinical and subclinical mastitisreduce milk production and farmers lose when they have to treatclinical cases, or cull cows because of mastitis, and face additionallabour and effort to prevent antibiotic residue problems.

The Australian Mastitis Advisory Council (AMAC) is made up ofrepresentatives of dairy farmer and processor peak bodies (AustralianDairy Farmers’ Federation [ADFF] and Australian Dairy ProductsFederation [ADPF]) and of farm adviser professions and industrygroups who have an interest in udder health. DRDC has provided mostof its financial support. AMAC has been endorsed by ADIC as theindustry forum for issues concerning mastitis and related milk quality.

AMAC has initiated a program called Countdown Downunder to helpfarmers and their advisers achieve profitable mastitis control.

This book is the first publication from Countdown Downunder. Itcontains the set of farm guidelines for udder health control whichpromotes best practice using currently available information. Tomaximise benefits to farmers, reduction of milk cell counts, clinicalcases and culling are all addressed.

The Technical Group of AMAC (Pauline Brightling, Graeme Mein,Jakob Malmo and Diane Ryan) drafted the recommendations andedited comments from more than 50 veterinarians, other advisers andfarmers throughout Australia. The result is an example of maximisingresources from research and the practical aspects of farmers’experiences.

I recommend we all use ‘Countdown Downunder: Farm Guidelines forMastitis Control’ for Australian dairy farmers’ to guide the udderhealth activities and keep the count down, and the profit up, on ourfarms.

Foreword

Pat Rowley CMGChairmanAustralian Dairy Industry Council

Pat Rowley CMGChairman

Australian Dairy Industry Council

ContributionsThe recommendations in this resource have been developed by theAustralian Mastitis Advisory Council’s technical group:

Pauline BrightlingProgram Leader

Australian MastitisAdvisory Council

Graeme MeinProfessor of Milking ResearchUniversity of Wisconsin, USA

Jakob MalmoPrincipal

Maffra Veterinary Centre

Diane RyanDairy Livestock Officer

NSW Agriculture

INTRODUCTION PAGE 1

What is Countdown Downunder? 1

What is mastitis? 3

Mastitis terminology 6

CALVING PAGE 13

1. Reduce exposure to environmental mastitis bacteria 15

2. Take care with two-year-old and freshly calved cows 17

3. Check that milk is suitable to go in the vat 19

4. Rapidly find, treat and record clinical cases in freshlycalved cows 20

LACTATION PAGE 25

5. Use good milking technique and a consistent routine 27

6. Monitor and maintain milking machine function 31

7. Use post-milking teat disinfection 37

8. Practise good hygiene during milking 40

9. Manage teat sores and cracks 42

10. Rapidly find, treat and record clinical cases 44

11. Monitor Bulk Milk Cell Counts 47

12. Use Individual Cow Cell Counts for management decisions 49

13. Seek professional advice if problems persist 51

LATE LACTATION PAGE 53

14. Decide dry cow mastitis strategy – drying off datesand Dry Cow Treatment 55

15. Cull persistently infected cows 58

Contents

DRYING-OFF PAGE 61

16. Dry-off abruptly taking steps to reduce yield 63

17. Administer Dry Cow Treatment as recommended 65

18. Check udders each day for a week 68

DRY PERIOD PAGE 71

19. Observe cows weekly 73

20. Selling cows – check withholding periods 74

21. Buying cows – check histories and examine udders 75

REVIEW AND PLANNING PAGE 77

22. Set time to do annual mastitis control activities andreview achievements 79

23. Sign on for milk recording 80

24. Review Countdown Downunder records 81

25. Test, service and upgrade milking machines 81

26. Service teat spray units and review teat disinfectant 82

27. Fix areas that make udders muddy 83

FACT SHEETS PAGE 85

A. Milk cultures 87

B. The correct way to give intramammary treatments 91

C. Guide to the choice of Selective or Blanket Dry Cow Treatment 93

D. Guide to withholding periods after use of Dry Cow Treatment 95

E. Records to keep on clinical cases of mastitis 97

F. AMMTA milking machine test report form example 99

G. The correct way to mix teat disinfectant 103

H. The impact of genetics on mastitis and cell counts 105

I. The impact of nutrition on mastitis and cell counts 107

J. The role of vaccination in mastitis control 109

INDEX PAGE 111

Introduction

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page 1

The information in this resource has been prepared for theAustralian mastitis program Countdown Downunder. Thisprogram is the national udder health program for the Australiandairy industry.

More than $130 million is lost to Australian dairy farmers each yearthrough poor udder health. Mastitis is the major cause of this loss.Mastitis reduces milk yield and leads to poor quality milk. Together,these factors erode the milk income received by farmers. Inaddition, antibiotic therapy used to overcome udder disease adds todairy farmers’ costs and requires strict monitoring to preventresidue entering the milk.

The Countdown Downunder plan consists of a set ofrecommendations to assist dairy farmers with profitable control ofmastitis.

For each period of the cow’s milking year Countdown Downunderprovides a set of guidelines about:

n what has to be done

n why it should be done

n how to do it

n how to check that it has been achieved.

Each guideline also has a Technote which summarisesthe experimental and observational data that underpins it.The Technotes are presented in a separate manual designedespecially for dairy service providers (includingveterinarians, factory field officers, milk recording fieldpersonnel and milking machine technicians). Theyprovide the rationale for the component of the plan,background information and bibliographic references forkey research papers and articles for further reading.

What is CountdownDownunder?

Introduction

Mastitis control:

nnnnn improves milk quality

nnnnn increases profits

nnnnn reduces anxiety forfarmers.

W hat are Countdown Downunder’sgoals?

The dairy industry must have a clean and healthy image to meet thedemands of national and international customers seeking betterquality milk through verifiable milk quality standards.

Mastitis degrades milk quality and diminishes the dairy industry’sability to compete in international markets.

Countdown Downunder has defined two national goals:

n at least 90% of Australian dairy farms supplying milk with acell count of less than 250,000 cells/mL in all milk supplyperiods

n 100% of Australian dairy farms supplying milk with a cellcount of less than 400,000 cells/mL in all milk supplyperiods.

Australian dairy farmers can make significant gains throughimproved udder health. Already, payment incentives exist in allstates for milk with lower cell counts.

Further, healthier cows produce more milk. They are less likely tobe lost through culling or to incur treatment costs. Fewer clinicalcases of mastitis mean less frustration for farmers and a reduced riskof antibiotic contamination of milk products.

Introduction

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ïïïïï Cow associated (orcontagious) mastitis

WWWWWhat is mastitis?

This section provides information about mastitis and defines variousterms related to mastitis. Mastitis is inflammation of the mammarygland. In cows it is usually caused by bacteria which have enteredthe teat canal and moved to the udder. The bacteria multiply andcause a mastitis infection which results in an inflamed udder.

W hat are the types of mastitis?

The main types of mastitis are:

n cow-associated (or contagious) mastitis

n environmental mastitis.

Bacteria which cause cow-associated (or contagious) mastitismostly live inside udders or on teat skin. They are spread frominfected cows.

The main bacteria causingcontagious mastitis are Staphaureus and Strep agalactiae.Transmission of these bacteriabetween cows and quartersusually happens at milking timeby contact with infected milk.This spread can occur fromsplashes or aerosols of milkduring stripping, by milk onmilkers’ hands or teatcup liners,and by cross flow of milkbetween teatcups.

Staph aureus can invade uddertissue and live inside cells. Theyoften form pockets of infection(microabscesses) that areprotected from antibiotics byscar tissue.

Cow-associated (or contagious) mastitis

Habitat Inside udders or on teat skin

How spread Contamination from infected milk

When spread Milking time

Bacteria Staph aureusStrep agalactiae

Comments Staph aureusare a major cause of mastitis inAustralia. They are difficult to cure,especially during lactation, soprevention is essential.

Strep agalactiaeare very sensitive to penicillin, sotreatment has a relatively high curerate.

Introduction

The Strep agalactiae bacteria tend to locate in duct areas of theudder where antibiotics are effective. Strep agalactiae is verysensitive to penicillin, so there are relatively high cure rates.

Bacteria which cause environmental mastitis are widespread in acow’s surroundings – soil, manure, bedding, calving pads and water,or on body sites of the cow other than the mammary gland. Housedcows are generally at greater risk than grazing cows.

The main bacteria are Strep uberis and E. coli. A number of bacterialike E. coli are often grouped together and called coliforms. Thesebacteria are not particularly well suited to life in the lactating udderand often the infections do not persist.

Most environmental mastitis cases are seen in the periodimmediately before, to a few weeks after, calving when cows arevery susceptible to infection because their natural defencemechanisms are low.

High numbers of environmental mastitis bacteria may contaminateteats, especially if udders are wet and exposed to mud and manure.This often happens when cows and heifers are on the ground duringcalving.

Environmental mastitis

Environmental mastitis ð ð ð ð ð

Coliforms ð ð ð ð ð

Habitat The cow’s environment, e.g. manure, soil.

How spread Contamination from infected environment; can be introducedwith intramammary tubes if teat ends are not sterile whentreatment occurs.

When spread Mainly at drying-off and around calving time; most cases seen atcalving or early lactation.

Bacteria Strep uberis , E. coli , coliforms, Pseudomonas. Many othersoccur occasionally.

Comments Often causes very severe or acute clinical mastitis.

Strep uberisusually responds to treatment, but can be difficult to cure.

Coliformsdo much of their damage through toxins released after thebacteria die. Antibiotics may not be needed. Do not usuallypersist in lactating udders.

Pseudomonasis virtually impossible to treat and cows that survive must beculled.

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page 5

Form ofmastitis Cow Udder Milk

ïïïïï Staph aureus, refer page 3

ïïïïï Strep agalactiae, referpage 3

W hy is mastitis control important?

National and international buyers of our milk products aredemanding ever increasing standards. If Australian dairy farmerswant to satisfy the buyers by producing the finest milk products,they must control mastitis.

W hat are the forms of mastitis?

The forms and signs of mastitis vary, depending on the bacteriacausing the infection and the immune response of the cow towardsthe bacteria.

Most cases of environmental mastitis are clinical (in all forms) butsubclinical cases do occur too.

Cases of mastitis caused by Staph aureus can be seen in all thevarious forms of mastitis.

Strep agalactiae does not produce black (gangrenous) mastitis butcan occur in all the other forms.

Severe Extremely ill and May become May intially look normal althoughclinical depressed, may gangrenous the cow is obviously sick, but soonmastitis die (black mastitis) becomes abnormal, often watery

and blood stained

Acute May or may not Hot, swollen and Abnormal and can be discolouredclinical be sick painful and contains clots and/or bloodmastitis

Clinical No observable Shows little Abnormalities are seenmastitis changes change

Mild clinical No observable Shows no A few clots or flakes occurmastitis changes abnormalities

Chronic No observable Lumps may be felt Mild changes, such as waterinessmastitis changes

Subclinical No observable No observable No observable changes butmastitis changes changes significant changes in milk

composition

Introduction

Somatic cells ððððð

Total Plate Counts ððððð

Cell count ððððð

Body cells ððððð

Individual Cow Cell ððððð

Count (ICCC)

Somatic Cell ðððððCount (SCC)

A higher financial gain can be achieved from increased production,higher payment for quality milk, and reduced costs of treatment andculling.

Fewer clinical cases of mastitis means there is less frustration forfarmers and less risk of antibiotic contamination of milk or meatproducts.

C ells in milk

When bacteria enter the udder, the cow responds by sending largenumbers of white blood cells to the mammary gland and into themilk. The white blood cells surround and destroy bacteria. They areone of the most important defence mechanisms the cow has to fightudder infection. There are also a small number (about 2%) of cellsshed into milk from the udder tissue. All these cells are from thecow’s body – they are not bacterial cells.

Body cells are sometimes called somatic cells (somatic means‘body’). The number of somatic cells does not increase after themilk leaves the cow, no matter how poor the filtration or cooling.

Cell counts in cows with Strep agalactiae may be extremely high,and occasionally there are also enough bacteria shed in the milk toraise Total Plate Counts (or Bactoscan Counts). Total Plate Countsassess the number of bacteria in milk, not cells in milk.

The concentration of all body cells in milk is called its cell count.Cells can be counted from individual cow samples and vat samples.

A sample of milk taken from all four quarters of a cow shows theconcentration of cow body cells. The sample is usually taken at aMilk Recording (Herd Testing) visit. It is referred to as anIndividual Cow Cell Count (ICCC) or Somatic Cell Count (SCC).

The concentration of cells in milk varies throughout a milking, sothe sample used to measure ICCC should be collected throughoutthe milking.

The concentration also varies between morning and eveningmilkings, especially with unequal milking intervals. Eveningmilkings are higher.

Introduction

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page 7

ïïïïï Dry Cow Treatment,refer page 8

ïïïïï Staph aureus , referpage 3

ïïïïï Strep agalactiae,refer page 3

ïïïïï Bulk Milk Cell Count(BMCC)

The ICCC is an indirect way of estimating the likelihood ofsubclinical mastitis in a cow. Uninfected cows generally have ICCClevels of below 150,000 cells/mL. If a cow has had any ICCC above250,000 during a lactation (a peak of 250,000 or more) she is likelyto still be infected at drying-off and require Dry Cow Treatment.

Different infecting bacteria may cause different ICCC patterns.Subclinical cases of Staph aureus may have cell counts that rise andfall, showing an irregular pattern during lactation. ICCCs in cowswith Strep agalactiae may be extremely high. Strep agalactiaeinfections are easier to treat than Staph aureus; so higher cell countsdo not always indicate that cows are harder to treat satisfactorily.

Stress may increase ICCC levels in cows, but the greatest increasesare seen in infected cows. Elevated ICCC levels which are notassociated with infection may occur for up to 20 days after calving.

Elevated ICCC levels may also occur in late lactation when milkvolume is low and cells are ‘concentrated’. Cows producing lessthan 5 L/day are likely to have abnormal milk composition,including elevated cell count.

The concentration of cow body cells that occurs in milk from allcows going into the vat is called a Bulk Milk Cell Count. TheBMCC is an indirect way of estimating the level of subclinicalmastitis in the herd.

As an approximate guide, each 100,000 cells/mL indicates about10% of cows are infected. Vat samples for BMCC should becollected via the drip sample which is taken when the vat is beingemptied. This ensures that the milk sample is well mixed.

A series of BMCCs should beassessed to see both the level andthe trend for a herd. In herdswith BMCCs below 200,000, asudden increase (of 10% ormore) may indicate that aclinical case has been missed.

Guides on BMCC levels

Below 150,000 cells/mL Excellent mastitis cell count control.

150,000 to 250,000 Good (below 250,000 is the level forpremium payment in most dairycompanies; some use 200,000).

250,000 to 400,000 Moderate mastitis and cell countcontrol.

Above 400,000 Warning: This milk is not consideredfit for human consumption by theEuropean Union and may lead tosignificant export restrictions.

Introduction

Blanket Dry Cow ððððð Treatment

Selective Dry Cow ððððð Treatment

ICCCs, refer pages 6–7 ððððð

C olostrum

Colostrum (sometimes called ‘beastings’) is the thick, yellow, stickysecretion that is present in the udder prior to calving. It containshigh levels of protein antibodies which form the basis of the calf’sinitial immunity.

After calving, colostrum is replaced by normal milk secretion, butsome is still present for up to eight milkings, even though the milklooks relatively normal by then. This colostrum milk must not beput in the vat. Fresh cows should be kept in a ‘colostrum mob’ untileight milkings have passed. Induced cows may have colostrumpresent for longer, and should be in the colostrum mob for at least10 milkings.

D ry Cow Treatment

Dry Cow Treatment (DCT) is a formulation of antibiotic preparedfor administration into the udder immediately after the last milkingof a lactation. It is designed to remain in the udder in concentrationshigh enough to kill mastitis bacteria for a period which depends onthe product used (approximately between 20 and 70 days). Theprolonged time of exposure to antibiotic and the formulationenhance penetration and give an increased chance of curinginfections embedded deep in the udder.

DCT may also be useful in reducing the number of new infectionswhich occur in the early part of the dry period, before the teat canalsseal.

DCT may be used in all cows within a herd (called Blanket DryCow Treatment) or only in cows which have been selected as likelyto be infected (called Selective Dry Cow Treatment). If SelectiveDCT is used, the most common way of selecting cows to treat is byanalysis of their Individual Cow Cell Counts throughout thelactation.

These decisions are discussed in Guideline 14 – Decide dry cowmastitis strategy and Fact Sheet C – Guide to choice of Selective orBlanket DCT.

Introduction

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page 9

ïïïïï National VendorDeclaration form,refer page 11

ïïïïï Forms of mastitis, referpage 5

ïïïïï Dry Cow Treatment, referpage 8

E xport Slaughter Interval

An Export Slaughter Interval (ESI) is the period following treatmentwhen cattle are unsuitable for processing for some export markets.A list of ESIs for veterinary chemicals can be found on the reverseside of the National Vendor Declaration form.

H and-held conductivity meters

Normal milk contains a small amount of salt which allows anelectric current to pass through it. When udder tissue is damaged,more salt leaks into the milk and it becomes more able to conductthe current – its ‘conductivity’ rises. There are several hand-heldmeters on the Australian market that enable farmers to checkconductivity of milk in each quarter of a cow. They are used to finddamaged quarters that have normal-looking milk – quarters withsubclinical infections or very early clinical cases before the milkchanges are visible.

The natural conductivity level of milk varies a lot between cows,and at different times during milking for each cow. To find adamaged quarter, it is best to compare between quarters in the samecow at the same time, rather than look for a particular absoluteconductivity level. The quarter which is significantly higher than theothers is most likely to be affected.

A single reading for a cow is not a very accurate way of decidingwhether to use Dry Cow Treatment. It is better to have a number ofreadings throughout lactation.

If a very early clinical infection is suspected by increasedconductivity only, check the quarter again at the next milking. It isusually not appropriate to treat cows based on conductivity resultsalone.

Introduction

Bulk Milk Cell Count, ððððð refer page 7

Total Plate Count, ððððð refer page 6

M aximum Residue Limit

The Maximum Residue Limit (MRL) is the maximum concentrationof an agricultural or veterinary chemical that is permitted in food(for dairy farms this means milk or meat from cows or calves).MRLs may vary between countries and are set by the nationalregulatory authorities responsible for food safety.

M ilk fever

Milk fever is a disease of mature dairy cows which usually occursjust before, or soon after, calving. It occurs when there is a suddenreduction of calcium level in the blood, and is also called‘hypocalcaemia’. Loss of calcium into the colostrum, insufficientabsorption of calcium from the gut, and insufficient mobilisation ofcalcium from the bones can all contribute to low blood calciumlevels. Cows with milk fever become weak, may go down, beunable to rise, and die if untreated. Injected calcium is a rapid curein most cases.

In the past, preventive management of milk fever sometimesinvolved leaving milk in the udder of fresh cows, but thispredisposes to mastitis. Current practices for milk fever controlinvolve manipulation of diet of cows before and at calving tomaximise calcium availability.

M ilk Quality Payment Schemes

Most dairy factories in Australia pay farmers different rates for milkof different BMCC quality (often as part of milk quality paymentschemes which also include a number of other factors such as TotalPlate Count). Milk supplied with a BMCC below a specifiedthreshold (for example 250,000 cells/mL) qualifies for a premium inaddition to the standard price. Milk with a BMCC above a specifiedthreshold may lead to a penalty below the standard price. In somestates there is a ceiling BMCC above which the factory will notcollect the milk.

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ïïïïï Refer to FactSheet A –Milk cultures, onpage 87

ïïïïï Let-down

M ilk culturing

A milk sample can be processed so that the bacteria that are presentcan be identified. This involves a laboratory spreading some of themilk on sterile plates covered with particular growth factors,incubating the plates for defined periods and assessing the bacterialcolonies that grow. This is called milk culturing.

N ational Vendor Declaration form

The National Vendor Declaration (NVD) is a nationally recognisedform filled out by farmers selling cattle. It provides a history of theanimals’ exposure to agricultural and veterinary chemicals. Thisallows an abattoir to slaughter an animal with confidence thatviolative residues will not occur, and that compliance withhormonal growth promotant restrictions for export markets will beachieved. Farmers selling for slaughter or feedlotting have theoption to complete an NVD. Failure to do so severely reduces buyercompetition, as many abattoirs and feedlots will not buy cattlewithout one.

O xytocin

Oxytocin is a hormone produced in the cow’s brain in response tothe stimulus of her calf sucking, or the anticipation of milking. Ittravels via the bloodstream to the udder where it causes specialmuscle cells to contract. These contractions squeeze milk into themilk ducts so that it can be removed from the udder. This process iscalled milk ‘let-down’, and oxytocin is often called the ‘let-downhormone’.

If cows are anxious or uncomfortable, let-down may fail. Oxytocincan be administered to help cows achieve let-down and to aid morecomplete removal of milk in inflamed udders.

Oxytocin is available as an injectable drug (brand names ofoxytoxin products currently available in Australia are: ButocinOxytocin Injection, Oxytocin Injection, Oxytocin-S and Syntocin).These are Schedule 4 drugs and can only be obtained through yourveterinarian.

Introduction

Maximum Residue Limit ððððð (MRL), refer page 10

Dry Cow Treatment, ððððð refer page 8

R apid Mastitis Test

Rapid Mastitis Test (RMT) is sometimes called Californian MastitisTest (CMT). This is a ‘cow-side’ test that is useful in detectingsubclinical mastitis by estimating the cell count of the milk. It doesnot give a numerical result but enables the milk to be categorisedinto one of five scores according to how much gel reaction there iswhen a reagent is added to it.

The test can be carried out during milking. A small amount of milkfrom each quarter is squirted into separate dishes on a paddle, andan equal amount of reagent is added to each. The solution is swirledto mix it, and the amount of gel reaction estimated (from none toalmost solidified). It is a cheap and relatively easy test that gives aresult at a quarter level. It requires some experience to read quicklyand efficiently.

U dder oedema

Udder oedema (sometimes called ‘flag’) is swelling which occursunder the skin of the udder, and sometimes along the belly, in cowsprior to calving. It mostly occurs in heifers at their first calving, butcan occur at subsequent calvings. The swelling may be great enoughto prevent easy milking and may interfere with the cow movingabout. Udder oedema is principally caused by changes in blood flowto the udder, where fluid drainage is compromised. Once milking isstarted, the volume of the udder is reduced and oedema fluid isusually cleared.

W ithholding period

The withholding period (WHP) is the minimum period of timewhich must elapse after the last use of a drug or chemical before thesale of a treated animal or product such as milk, for humanconsumption. (The exception is the WHP for milk after use of DryCow Treatment, where the WHP is the time that must elapse aftercalving, provided the specified minimum dry period has occurred.)Withholding periods are set to ensure that when a drug or chemicalis used in accordance with the directions on the label, no residueswill exceed relevant Australian Maximum Residue Limits (MRLs).

CALVING

Two weeks before calving to two weeks after

Guideline Page

11111 Reduce exposure to environmentalmastitis bacteria 15

2 Take care with two-year-old andfreshly calved cows 17

3 Check that milk is suitable to go inthe vat 19

4 Rapidly find, treat and record clinicalcases in freshly calved cows 20

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Reduce exposure toenvironmental mastitisbacteria

1nnnnn calving environmentnnnnn induced cowsnnnnn milk fever

nnnnn milking fresh cowsnnnnn premilking preparation

GUIDELINE

Cows are very susceptible to infection around calving because their natural defence mechanisms

are low. New infections occur, and subclinical infections which have persisted through the dry

period may flare into clinical cases. Induced cows are even more vulnerable to mastitis infections

because their immune systems have reduced efficiency at that time.

Around calving, the udder is often filled with milk for relatively long periods without the flushing

effect of being milked. Bacteria may enter the end of the teat, particularly if high udder pressure

opens the teat canals. They can then multiply and establish infections. High numbers of

environmental mastitis bacteria may contaminate teats, especially if udders are wet and exposed

to mud and manure. This can happen easily when cows and heifers are on the ground during

calving.

Because of the high incidence of mastitis in the first month after calving, special care in this

period will pay off.

1.1 Calve on clean, dry pasture or on aclean, dry calving pad.

Pasture or pads for calving must have minimalmanure contamination. If more than two pats ofmanure are present per square metre, it is notclean enough for calving cows.

The calving area should be sheltered and welldrained. Avoid pugging and mud. If water isvisible on the surface or in your gumbootprints, it is not dry enough for calving cows.

It is important to check forabnormal milk and treatinfections rapidly.

Milk fever, refer page 10 ððððð

Refer to Guideline 5 – ðððððUse good milking

technique and aconsistent routine,

page 27

Guideline 1Environmental exposure

1.2 Be alert to the number of cases of mastitis occurring,especially in freshly calved heifers. This is an indicatorof the state of the paddock.

If three or more cases have occurred in the last 50 calvings,you should move the springers to a new area, or renovate thepad.

1.3 Bring cows into the dairy as soon as possible to milkout and check – certainly within 24 hours of calving.

A new calf cannot suck all the milk from a fresh cow. Do notleave cows standing in the paddock dripping milk – bringthem into the dairy, check udders, machine milk and disinfectteats (dip or spray).

Milk out completely – use milk fever control methods such asdietary control or calcium treatment (not incomplete milking)to prevent milk fever.

1.4 Take special care with induced cows.

Keep them in clean, dry paddocks after induction.

Machine milk them if they bag up tightly. Don’t let them dripmilk in the paddock.

Watch udders carefully for signs of mastitis. Some cases canbe rapid and severe with few changes or abnormalities (e.g.watery milk, clots or flecks) in the milk at first.

1.5 Take care with premilking preparation of udders.

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2 Take care withtwo-year-old andfreshly calved cows

nnnnn milk let-downnnnnn milking out

GUIDELINE

nnnnn training heifersnnnnn udder oedema

After calving, cows are often uncomfortable with swollen udders and may be more difficult to

move, handle and milk out completely. For young cows calving for the first time, the milking

routine is a new and different experience.

It takes about two weeks for most heifers to establish a quiet, reliable response to milking.

Milking staff must be patient and as gentle as possible during this period. This is important to

maximise production, minimise milking times and minimise risks of injury to milkers and animals.

Extra labour may be required in seasonal herds.

Udder oedema in a freshlycalved cow.

ïïïïï Udder oedema, refer page 12

2.1 Consider training heifers in the milking area beforecalving.

Familiarise heifers with the surroundings of the milking area,and entry and exit routes.

2.2 Take your time moving and milking two-year-old cowsand freshly calved cows – don’t rush.

This minimises injury to udders and teats, and contributes tocows being comfortable during milking.

Encourage the co-operation of the animal by gentle hus-bandry.

2.3 Attend to two-year-old cows with severe udderoedema (flag).

If heifers are tight with udder oedema prior to calving, milkthem out and use saved colostrum for their calves.

Guideline 2Fresh cows

Oxytocin, refer page 11 ððððð

Refer to Guideline 5 – Use ððððð good milking technique and a consistent routine, page 27

If they are very uncomfortable, seek veterinary advice. Pre-vention is better than cure, so discuss heifer nutrition withyour adviser to ensure diet doesn’t contribute to severe flag-ging.

2.4 Ensure all quarters of all cows are milked out.

Ensure there is milk let-down at each milking, particularly inheifers. Use let-down hormone (Oxytocin) if necessary.

Avoid both under milking and over milking.

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Check that milk is suitableto go in the vat

ïïïïï Dry Cow Treatment,refer page 8

ïïïïï Colostrum milk,refer page 8

3nnnnn Dry Cow Treatmentnnnnn colostrum milk

GUIDELINE

ïïïïï Refer to Fact Sheet D –Guide to withholdingperiods after use of DryCow Treatment, page 95

For milk quality reasons, all cows should have their colostrum

milk withheld from the vat for at least eight milkings after

calving (10 milkings for induced cows). For cows that have

received Dry Cow Treatment (DCT), a withholding period for

milk after calving is specified for each product.

All DCT products are registered with a specified Minimum Dry

Period after treatment. If a cow calves in less than this time,

withholding periods for milk and calf meat may be much longer

than in the usual situation.

3.1 Ensure each cow has exceeded her Dry CowTreatment Minimum Dry Period before putting her milkin the vat or selling her calf.

3.2 Ensure that milk from the colostrum phase (first 8milkings) is not included in the vat(10 milkings for induced cows).

Feed this milk to replacement heifers rather than bobby calveswhere possible. Feeding this milk to replacement heifersminimises the risk of antibiotic residues from Dry CowTreatment in bobby calves. It also provides good nutrientintake for heifers even after the antibody absorption periodhas passed.

Rapidly find, treat andrecord clinical cases infreshly calved cows

4GUIDELINE

nnnnn antibiotic contaminationnnnnn antibioticsnnnnn bacteria spreadnnnnn cluster handlingnnnnn colostrum milknnnnn marking systemsnnnnn mastitis herd

nnnnn milk culture samplesnnnnn record systemnnnnn strippingnnnnn swollen quartersnnnnn veterinary advicennnnn withholding times

Clinical mastitis, ðððððrefer page 5

Bulk Milk Cell Count, ðððððrefer page 7

Milk cultures identify thebacteria that havecaused the mastitisinfection. Refer page 11.

Oxytocin, refer ðððððpage 11

Early detection and treatment of clinical mastitis cases in the

calving period reduces the risk of severe cases developing. It also

reduces the likelihood of infection being passed to other cows,

and the development of chronic infections.

Clinical cases which are missed can markedly increase the Bulk

Milk Cell Count because they produce very high numbers of cells.

A case of clinical mastitis which requires treatment occurs when

there is heat, swelling or pain in the udder, or there are changes in

the milk (wateriness or clots) that persist for more than three

squirts of milk.

By recording cow identity and drugs used for all cases, numbers

of clinical cases and responses to treatment can be monitored.

Your herd has a significant problem if there are more than five

clinical cases per 100 cows in the first month of lactation, or two

clinical cases per 100 cows in subsequent months of lactation.

Milk cultures are recommended to identify which bacteria are

involved if a herd problem emerges. A sterile sample must be

taken before treatment is started for each case.

More than 80% of clinical mastitis cases in Australia are caused

by Staphs or Streps which should be treated with antibiotics.

It is also very important to remove infected milk from the udder by

stripping out. Sometimes use of let-down hormone ( Oxytocin ) is

helpful especially with hard, swollen quarters.

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Guideline 4Fresh cow clinicals

4.1 Look for swollen quarters and check for heat and painin all freshly calved cows.

A swollen quarter will appear larger than other quarters on thesame cow.

4.2 Check milk from all quarters of freshly calved cowsevery milking while they are in the colostrum phase(first 8 milkings, or 10 milkings for induced cows).

Changes can be hard to assess in milk in the first few daysafter calving. Look for watery milk, clots or flecks. Some-times with severe mastitis, such as mastitis caused byE. coli, visible changes are not obvious in the milk.

Comparison between quarters is often helpful. Check thequarters you think are normal first. Milk containing infectionmay be spread during this procedure, so avoid splashes orsprays of milk aerosol.

Gloves should always be used when checking for mastitis.Good milkers learn to avoid getting milk on their gloves.

4.3 Consider collecting milk samples for culture to identifythe bacteria involved.

Samples for mastitis culture can be frozen and stored beforebeing sent to the laboratory. Storage for more than about fourweeks reduces the chance of obtaining a positive cultureresult.

If you have had more than three clinicals in the past 50calvings, or are concerned about the number of clinical casesof mastitis as the year progresses, these frozen samples can besubmitted for laboratory examination.

4.4 Select the antibiotic to be used – consult yourveterinarian.

Issues to be assessed include:

n bacteria previously cultured and antibiotic responses inyour herd

n assessment of likely bacteria in this particular case

n published cure rates of the products available

n withholding periods of the products available.

ïïïïï E. coli , refer page 4

ïïïïï Refer to Fact Sheet A –Milk cultures, page 87

Checking a quarter of afreshly calved cow.


In some circumstances, injectable antibiotic may be beneficial.Never use Dry Cow Treatment for clinical cases.

Always read the label on the antibiotic product.

4.5 Administer the treatment as recommended.

Strip out the quarter fully before infusing antibiotic into thequarter. This may be assisted by injecting 2-3 mL of Oxytocininto the muscle before you commence stripping.

Ensure that teats and gloves are clean.

Scrub the end of the teat with 70% alcohol before inserting thetube.

4.6 Use the full course of antibiotics (as specified on thelabel).

Only treat the quarters that are affected.

Check all quarters every milking during the full course.

4.7 Milk the quarter out fully at least every milking.

Stripping out infected milk from clinical quarters improvescure rates. Frequent stripping (three or four times per day)removes debris from the quarter.

Use of let-down hormone (Oxytocin) may be helpful in re-moving milk from hard, sore quarters.

4.8 Clearly mark treated cows.

Set up a system that works for you and ensure that all regularand relief milking staff are familiar with it.

Systems for temporary identification of treated cows should behighly visible, easy to apply and to remove. The mark shouldbe durable enough to last for the full treatment and withhold-ing period of the drug. Different colours or marking codes maybe used to signify when withholding periods are complete.

Dry Cow Treatment, ððððð refer page 8

Refer to Fact Sheet B – ðððððThe correct way to give

intramammary treatment,page 91

Examples of markingsystems:

nnnnn ratchet-type plastic tailtags

nnnnn insulation tape on the tail

nnnnn velcro bands above thehocks or on the legs

nnnnn paint (tailpaint, enamel ornon-scourable spraypaint) on the udder orlegs.

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4.9 Record all details.

A clear, easily seen record should be kept in the shed forquick reference during milking. A whiteboard can be helpful.

It is now possible to permanently record details of clinicalcases through most of the Milk Recording systems. See yourHerd Improvement service for details.

4.10 Observe withholding times for milk and meat.

Read the label of the drug used.

4.11 Discard milk from all quarters of cows that receivetreatment.

Some antibiotic will be absorbed into the bloodstream andpassed out in the milk from the normal quarters. The risk ofantibiotic contamination is too great to include it in the vat.

4.12 Make a particular effort to minimise spread of bacteriafrom infected cows to other cows.

Draft out clinical cases and milk them last.

Run a separate mastitis herd if you can.

Use gloves when milking mastitis cows.

If mastitis cows are not milked last as a separate group, use aseparate, good quality cluster for mastitis cows on the testbucket. Mark the cluster with some red tape to remind allpeople milking that it is only to be used for mastitis cows.

Rinse and then sanitise the cluster after milking each mastitiscow. Remove the long milk tube and run water through thecups and claw bowl for 30 seconds. Then dip the cluster andyour hands in a disinfecting solution such as 1% Iodophor.Disinfectants take time to kill bacteria, so don’t touch anyother cluster or cow for at least 20 seconds. Drying hands on apaper towel after this will also help reduce the bacteria thatstill remain.

ïïïïï Refer to FactSheet E – Recordsto keep on clinicalcases of mastitis,page 97

Do not dip the clusterunless you have rinsed itfirst because progressivecontamination of thebucket leads to a ‘soup’of bacteria.

4.13 Consult your veterinarian for advice about thefollowing options if a clinical quarter fails to respondby the end of a full course of treatment (as listed onthe label):

n repeating the same treatment

n trying a different antibiotic

n drying-off the quarter (provided it is not hot or swollen)

n drying-off the cow

n culling the cow, after the withholding period for meathas expired

n culturing the pre-treatment sample or re-sampling thequarter.

Do not use drugs in any way other than specified on the label.Don’t change the dose rate or dose frequency specified on thelabel. This will change the withholding period required.

If drying off a quarter, stop milking it and monitor the quarterto ensure it does not become hot and swollen. If it does, stripit out again.

Do not use Dry Cow Treatment in a quarter when you arecontinuing to milk the other quarters. Dry Cow Treatmentsare not registered for use in lactating cows. Some antibioticwill be absorbed into the bloodstream and passed out in themilk from the normal quarters, so there is a high risk ofantibiotic contamination of the vat.

If culling the cow, check that the withholding period for meathas elapsed for all drugs used.


Withholding period, ððððð refer page 12

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LACTATION

Guideline Page

5 Use good milking technique and aconsistent routine 27

6 Monitor and maintain milking machinefunction 31

7 Use post-milking teat disinfection –spray or dip every teat at every milking 37

8 Practise good hygiene during milking 40

9 Manage teat sores and cracks 42

10 Rapidly find, treat and record clinicalcases 44

11 Monitor Bulk Milk Cell Counts 47

12 Use Individual Cow Cell Counts formanagement decisions 49

13 Seek professional advice if problemspersist 51

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Use good milking techniqueand a consistent routine5

nnnnn calm cowsnnnnn clean, dry teatsnnnnn foremilk strippingnnnnn good stockmanship

nnnnn machine strippingnnnnn teatcups onnnnnn teatcups off

ïïïïï Staph aureus and Strepagalactiae , refer page 3

GUIDELINE

ïïïïï Bulk Milk Cell Count, referpage 7

ïïïïï Foremilk stripping

During lactation, cow-associated mastitis bacteria such as

Staph aureus and Strep agalactiae are transmitted between

cows during milking. Milk from one infected quarter is spread

to the teat skin of other quarters and cows by milkers’ hands,

teatcup liners and cross flow of milk between teatcups.

Damaged teat ends are particularly susceptible. Malfunction or

poor use of the milking machine can contribute to

transmission of infection.

Prevention of infection involves: keeping cows calm and teat

ends healthy; careful use of machines that are operating well;

disinfection of teat skin after milking.

Staph aureus is a major cause of mastitis in Australia. It is

difficult to cure, especially during lactation, so prevention is

essential.

5.1 Ensure that cows enter the milking shed willingly byuse of good stockmanship.

Calm cows manure less frequently, kick the cups off less oftenand have better milk let-down.

5.2 Consider foremilk stripping for all cows in their firstmonth of lactation.

Foremilk stripping is the single most effective way to detectclinicals. Consider foremilk stripping all cows in their firstmonth of lactation in periods of high risk. (For example, if theclinical case rate is high, or when Bulk Milk Cell Count isapproaching a penalty threshold.)

Flaming is singeing hairswith a cool flame. Yourveterinarian can adviseyou on flaming.

Guideline 5Milking technique

Refer to Guideline 27 – ðððððFix areas that make udders

muddy, page 83

Routine fore-stripping of cows in the first month of theirlactation also helps to accustom cows to having their teatstouched and provide an effective ‘signal’ for milk let-down.

If done poorly, however, fore-stripping contributes to thespread of bacteria from teat to teat via milkers’ hands. Goodmilkers will take care to avoid ever getting milk on theirhands while foremilk stripping.

An effective technique is to squeeze the base of each teatbetween the thumb and the first two fingers, then pull gentlydownwards. If no clots, flecks or other abnormalities appearin the first two squirts, move to the next teat.

5.3 Put teatcups on clean, dry teats – only wash dirtyteats.

Ideally, teatcups should only go on to clean and dry teats.

Milking wet teats is unacceptable, both for risk of mastitisand milk quality issues. Avoid wetting the udder – just wet theteats if they need to be washed.

Always use clean, low pressure water to wash dirty teats.

Teats are rarely dry when teatcups are put on if they aresimply left to ‘drip’ dry. Effective drying is achieved withsingle use paper towels or suitable woven cloths (such as‘Chux’ towels). Each cloth must only be used for one cow permilking. Cloths should then be placed in disinfectant solution,washed and wrung out before the next milking. Never userags.

Minimise hair contamination by trimming or flaming hair onudders.

Trim cows’ tails. Completely remove the long hair on the end.Repeat twice a year if necessary.

If teats are dirty, check that laneways and areas aroundtroughs, gates and the entrance to the shed are drainingadequately and not contributing to dirty teats. Do repairs ifnecessary.

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5.4 Put teatcups on when teats become plump with milk.

Putting cups on too soon usually results in teatcups crawlingduring the first minute of milking. When teatcups crawl earlyin milking, milk harvesting is less complete and less efficientnear the end of milking.

The optimum time to apply teatcups is 60–90 seconds afterthe cow’s teats and udder are first touched by the milker, orthe sights and sounds of milking and the predictability of acalm, consistent milking routine have stimulated good milklet-down.

Choose a set of procedures that allows or (preferably) requireseach milker to be absolutely consistent at every milking.

In herds which have good milking routine without physicalstimulation of the teats, the simplest way to match the timingof cup application with milk let-down is to delay the time ofcups–on by about 30–60 seconds. For example, on rotaries thecups–on operator could move one cow further round.

5.5 Eliminate machine stripping from your milking routine.

Extra weights on cups affect their balance and increase cupslippage which increases the risk of mastitis.

5.6 Allow minimum air to enter cups when attachingclusters.

The milk carrying capacity of the milkline is reduced by theair admitted when teatcups are attached or removed.

To minimise air leakage through teatcups:

n ensure that teatcups match claws correctly (so cupshang over claw inlets properly)

n during milking, balance the cluster carefully, and lifteach teatcup with a ‘kink’ in the short milk tube untilthe moment of attachment.

Refer to Guideline 6 – ðððððMonitor and maintain

milking machinefunction, on page 31


Taking off cups by kinkinglong milk tube and cupsfalling away by gravity.

5.7 Take teatcups off by cutting the vacuum and allowingthem to slip free of the teats. Do not break the vacuumat the mouthpiece lip of the liner.

Air entering at the cup mouth, because of liner slip or roughcup removal, causes vacuum fluctuation in the cluster. Milkdroplets may be thrown back against the teat ends. Theseimpacts carry bacteria into the teat canal where they arebeyond the reach of a teat disinfectant.

5.8 Avoid under and over milking.

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6 Monitor and maintainmilking machine function

nnnnn air ventsnnnnn changing teatcup linersnnnnn cow behaviournnnnn cup slipsnnnnn daily checksnnnnn milking machine techniciannnnnn milking time guides

nnnnn monthly checksnnnnn pulsatorsnnnnn receival cannnnnn regulatorsnnnnn vacuum gaugennnnn vacuum reservennnnn weekly checks

The most common reason for milking machine problems is inadequate routine maintenance of

mechanical components and rubberware. A series of regular, systematic checks gives a simple

method of finding problems and guiding preventative maintenance.

If more than one person milks in your shed, it is important to assign these checking tasks to

particular people, and ensure that the right person is alerted to any problems that are found or

suspected. Daily and weekly checks should be conducted by milking staff as part of their regular

list of responsibilities. The monthly checks should be done by the herd owner or manager or

other skilled observer.

Recording the results of monthly checks enables subtle changes due to wear and age to be

detected more easily.

GUIDELINE

6.1 Use daily, weekly and monthly guides to checkmachine function.

Daily, weekly and monthly checklists are provided on thefollowing pages.

Typical vacuum levelrecommendations are:

High line 48–50 kPa

Mid line 46–48 kPa

Low line 42–45 kPa

Guideline 6Machine function

Daily checksn Check the air admission holes (air vents). If the air vent is

blocked, the claw bowl fills with milk and leads to more cupfalling, slow or incomplete milking, and difficulty removingclusters even after the vacuum is cut off. Remove any debriswith the probe designed for the task – avoid using drill bits orother tools that may enlarge the holes.

n Read the vacuum gauge. Tap the face of the gauge to ensurethat the needle isn’t sticking.

n Listen to pulsators. The sound of air entering the external airport should be both regular and intermittent. It should be thesame sound for all pulsators.

n Watch milk entering the receival can. Flow should be even,without flooding or slugging.

n Check teats as the cups come off at the end of milking.Look for discolouration (reddish, bluish or purplish teat skincolour).Look or feel for swelling or hardness at the top, middle or endof the teats.Examine teat openings for signs of cracking, sores or teatcanal lining pulled out of the opening.Observe if teats are unusually sensitive to touch.

n Check cow behaviour. Are cows nervous and uncomfortablewhen teatcups are put on or removed from teats, or duringmilking?

Daily checks 4

Check air admission holes (air vents)

Read the vacuum gauge

Listen to pulsators

Watch milk entering the receival can

Check teats as cups come off

Check cow behaviour

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Note: Liners should beremoved from jettersystems which stretchmouthpieces. Preferablyuse jetters which washboth the inside and outsideof the mouthpiece and canbe left connected so thatafter washing the system issealed. This reducescontamination by dust orflies.


Weekly checksn Check for twisted liners.

Align marks on mouthpiece and stem of liner, or place yourthumb in each liner.

n Check liner condition.

Look particularly for distortion of the mouthpiece lip or holesin the short milk tube. Split liners lead to fluid between theliner and the teatcup shell.

n Check filters on pulsator airlines especially on rotary dairieswhere the filters are close to the feeders.

n Listen to the regulator(s).

Weekly checks 4

Check for twisted liners

Check liner condition

Check filters on pulsator airlines

Listen to the regulator(s)


Monthly checksn Check ‘effective reserve’ of vacuum and regulator function.

With the machine running, open one set of cups (or if morethan 32 units, open two sets). If vacuum drops more than 2kPa, then effective reserve is not adequate.

During this test, check that the regulator closes or almostcloses. The hiss of air entering the regulator should be greatlyreduced when the cups are opened. If this does not happen,check the regulator filter and clean if necessary. If cleaningdoes not improve the regulator response, call your AMMTAmilking machine technician.

n Measure completeness of milking and milking times.

If cups are applied before milk let-down, these average milk-ing times should be extended by approximately one minute.

n Count cup squawks and slips requiring correction by milker.A running tally over 15 minutes of milking provides a guide.To assess machine function, exclude cows with very poorudder conformation which always have cups slip.

Preferred machine function:

n no more than five slips per 100 cows.

Machine requires service:

n more than 10 slips per 100 cows.

Milking time guideUnder milking: Handstripping of at least 10 cowsshould give less than anaverage of 250 mL/cow. Ifmore than 500 mL/cow ismeasured, there is asignificant problem withunder milking.

Average milking: With goodmilk let-down (teats plumpwith milk) and correctlyadjusted milking equipment,95% of cows giving:

nnnnn 10 L/milking should milk in5 minutes (+/– 1 minute)



Monthly checks Your figures this month

Check effective reserve andregulator functions

Measure completeness ofmilking and milking times

Count cup squawks and slipsrequiring correction by milker

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ïïïïï Refer to Fact Sheet F –AMMTA milking machinetest report form example,page 99


Most manufacturersrecommend that rubberliners are used for 2000–2500 cow milkings, afterwhich they should bechanged.

6.2 Call a milking machine technician if you observe anyabnormalities in the dairy shed during your daily,weekly or monthly checks.

Arrange a visit by a technician with a current AMMTAqualification to correct the problem you have observed and:

n ensure vacuum levels and airflows are appropriate formachine

n check pulsation

n service faulty pulsators

n correct all faults promptly.

Vacuum recordings made during milking can be helpful inpinpointing some machine faults.

You should receive a full written report on a current AMMTAform from your milking machine technician service.

6.3 Change liners at regular intervals.

Teatcup liners are designed to flex and squeeze the teat duringeach pulsation. This is essential to massage the teat andmaintain its blood supply. When fitted into a correctlymatched teatcup, the liner should be stretched 5–15% morethan its original length.

As soon as they start work, liners begin to lose tension, absorbfat and hold bacteria. Once they have been used for too manycow milkings, the deterioration is sufficient to reduce thespeed and completeness of milking, increaseteat end damage, and increase spread of mastitis bacteria.

The effective life of liners is influenced by the characteristicsof the materials they are made from, and the storage, cleaningand use they experience. Most manufacturers recommend thatrubber liners are used for 2000–2500 cow milkings, afterwhich they should be changed. Some manufacturers alsospecify a time of 4–6 months as the maximum recommendedlife for liners under tension and exposed to sun, heat, chemi-cals and ozone.

Number of days =

2500 x number of milking units

number of days = = = 125 days 2500 x 12

120 x 2

30,000

240

herd size x number ofmilkings per day

For example:

A herd of 120 cows (herd size) milking twice per day(milkings per day) in a 12 unit swingover shed (milkingunits) would take 125 days (number of days).

Measure liner life in ‘cow milkings’.

When liners are changed, estimate when the next 2500cow milkings (or manufacturer’s recommendation) willhave occurred, and mark the date to replace liners on yourcalendar.

Guide to estimating number of daysfor 2500 cow milkings:


Most liners have two or more ‘tension notches’ at their base.These enable the liners to fit a number of teatcups of slightlydifferent lengths, and also allow the liners to be ‘pulled up’onto the next notch to increase tension after some use hasoccurred. Over-stretched liners may provide good milkingcharacteristics but are more likely to cause teat damage.

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7 Use post-milking teatdisinfection – spray or dipevery teat at every milking

nnnnn applicationnnnnn dip cup cleaningnnnnn disinfectantsnnnnn emollients

nnnnn ingredientsnnnnn iodinennnnn operator techniquennnnn water quality

ïïïïï Staph aureus , refer page 3

GUIDELINE

Bacteria in milk from infected quarters may contaminate the

skin of many other teats during milking. For example, after a

liner has milked an infected quarter, bacteria may be

transferred to the next 5–6 cows milked with that cup.

After milking, bacteria multiply on the teat skin and may

extend into the teat canal. If the whole surface of each teat is

disinfected immediately after milking, this spread can be

minimised.

Teat disinfection after milking reduces by 50% new infections

due to cow associated bacteria such as Staph aureus . It is one

of the most effective cell count and mastitis control measures

available, but it only works if it is done thoroughly.

Teat disinfectants must be diluted to the correct concentration

for use. The active ingredients often lose their disinfectant

ability with time after mixing, and if you include additives to

improve skin condition (emollients) these may reduce

disinfectant activity. Any contamination with milk and other

organic material also reduces activity. Correct mixing each day

is best to get maximum performance.

Some emollients (for example, bloat oil) are not suitable for

use with particular disinfectants.

Failure to cover the whole teat of every cow at every milking is

the most common error in teat disinfection.

Refer to Fact Sheet G – ðððððThe correct way to mix

teat disinfectant, page 103

Guideline 7Teat disinfection

Pseudomonas, refer ðððððpage 4

7.1 Use a teat disinfectant registered by the NationalRegistration Authority.

These have a ‘Poisons Schedule’ rating shown on the label.

7.2 Mix a fresh batch every day.

7.3 Use water of very high quality.

Cooled water from the hot water service is a good source.

River or dam water or water from tanks with high organicmatter content is unacceptable because of the inactivation ofthe disinfectant, and the risk of contamination with bacteriasuch as Pseudomonas which cause very severe mastitis whichis virtually impossible to treat.

Water very high in minerals is also unacceptable.

7.4 Ensure the dilution gives at least 0.5% iodine forIodophor products. Mix other products according tothe label directions.

7.5 Maintain teat condition – emollients (such asglycerine) may be added to improve teat skincondition.

Glycerine is a preferable teat skin emollient to bloat oil oremulsified paraffin (white oil) products. Although bloat oil orparaffin is relatively cheap, it does not mix with water and ithas to be shaken frequently to avoid it ‘separating out’.

Other good emollients include glycan, sorbitol andlanolinated esters.

Never use bloat oil (or any white oil) in chlorhexidine disin-fectants.

Do not use any emollients with chlorine disinfectants.

Do not exceed 10% glycerine for regular use. Higher levelsmay interfere with killing power of the disinfectant. If teatcondition is particularly bad or irritation of teat skin hasoccurred with a change in chemical use (for example withchange of teat disinfectant or teatcup liners) glycerine concen-tration may be increased to 20% but for no more than twoweeks.

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Checking teat disinfection spray pattern.

Guideline 7Teat disinfection

7.6 Spray or dip the whole surface of all teats after everymilking throughout lactation.

Ensure the whole teat surface is covered with disinfectant. Allthe teat surface touched by the teatcup liner must be covered.A drop of teat disinfectant seen at the end of the teat does notindicate adequate coverage.

Spray upwards from beneath teats, not from the side.

Do not spray cows as they walk past.

Dipping is more reliable than spraying for getting completecoverage.

7.7 Check operator technique.

Check that at least 20 mL of prepared teat disinfectant isbeing used per cow per milking if spraying (10 mL per cowper milking if dipping). Adequate volume alone, however,does not ensure teats are being covered.

Check spray pattern of spray units. Hold a sheet of whitepaper 10 cm from spray and spray it like you would a teat.Hollow ring spray patterns miss the teat. If required, changeor service nozzles.

Check the ‘far sides’ of teats of at least some cows afterspraying or dipping every day to ensure they have been cov-ered.

7.8 When dipping, clean out dip cup as teat dip gets low –don’t just top up the dip.

Minimise the amount of milk or other organicmaterial that accumulates in the dip cup.Clean out immediately if there is dirt ormanure dropped into the cup, and wash outthe dip cup every day.

8 Practise good hygieneduring milking

nnnnn cluster techniquesnnnnn disinfectant use

nnnnn milk splashesnnnnn separating infected cows

Bacteria are present in milk from all infected quarters. They are

spread to other quarters and cows by splashes or aerosols of

milk that occur during stripping, by milkers’ hands, teatcup

liners and by cross flow of milk between teatcups.

Clinical cases and chronically infected cows are a source of

infection for healthy, young cows – if these mastitis cows are

milked last, the risk of spreading infection is markedly reduced.

If clinical cases are not milked last, using a separate cluster for

mastitis cows on the test bucket also reduces the risk of

spread from contaminated liners.

GUIDELINE

Do not dip clusters orhands unless you haverinsed them first becauseprogressive contaminationof the bucket leads to asoup of bacteria.

8.1 Avoid splashes or sprays of milk aerosol. Never getmilk on your hands.

Gloves should always be used when searching for or dealingwith clinical cases of mastitis. Good milkers learn to avoidgetting milk on their hands.

8.2 Use running water and disinfectant solution to removeinfected milk from gloves, liners and other equipment.

Rinsing with running water for about 30 seconds provides aphysical wash. Then dipping in a disinfecting solution such as1% Iodophor provides a sanitising effect.

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ïïïïï Refer to Guideline4 – Rapidly find,treat and recordclinical cases in freshlycalved cows, page 20

Guideline 8Good hygiene

ïïïïï Cell counts, refer page 7

Disinfectants take time to kill bacteria, so don’t touch anyother unit or cow for at least 20 seconds. Drying hands on apaper towel after this will also help reduce the bacteria thatremain.

8.3 Draft out clinical cases where possible, and milk themlast. Run a separate mastitis herd if you can.

8.4 Use a separate cluster for clinical mastitis cowsmilked with the herd and clean thoroughly betweeneach cow.

Mark the cluster with some red tape to remind all peoplemilking that it is only to be used for mastitis cows.

Rinse and then sanitise the cluster after milking each mastitiscow.

8.5 Consider identifying high cell count cows and milkingthem last, preferably by running a separate herd.

9 Manage teat soresand cracks

nnnnn disinfection mixnnnnn machinery checknnnnn mud problemsnnnnn teat ointmentsnnnnn teat skin

nnnnn teat soresnnnnn veterinary advicennnnn water accessnnnnn washing teats

1 Normal teat after milking (photo 1).

2 Red discolouration and swelling after milking (photo 1).

3 Small haemorrhages at the teat end (photo 3).

4 Haemorrhages extended to break the skin (photo 4).

Teats 2 to 4 have been milked with inadequate pulsation.

GUIDELINE

Teat sores (especially at the ends of teats) provide sites where bacteria can multiply. Mastitis risk

is a numbers game – greater numbers of bacteria near the teat end increases the risk of

infections occurring. Teat sores are painful and lead to poor cow behaviour, with increased

dunging and kicking and poor milk let-down.

Healthy teat skin is easier to keep clean, minimising preparation before milking.

Teat skin health is affected by exposure to mud and water, and milking machine factors. Water is

harmful to teat skin because it removes protective natural oils. It increases the likelihood of

cracks developing on teats (and milkers’ hands).

1 2 3 4

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A teat sphincter isthe teat canalopening.

ïïïïï Refer to Guideline 6 –Monitor and maintainmilking machine function,page 31

Guideline 9Teat sores

ïïïïï Refer to Guideline 7 –Use post-milking teatdisinfection, page 37and Fact Sheet G – Thecorrect way to mix teatdisinfectant, page 103

9.1 Assess teat skin and teat ends every milking.

If teats are discoloured (red, blue or purplish) there is likely tobe teat end damage due to faulty machine function. Teatsphincters should be clean, white rings.

9.2 Reduce mud problems by maintaining clean and drytrough areas, farm tracks, laneways, gates, andentrances and exits to the dairy area.

9.3 Ensure cows don’t have access to creeks, dams andwatercourses.

9.4 Minimise use of water on cows in the dairy.

Ideally, teatcups should only go on to clean and dry teats.

Avoid wetting the udder – just wet the teats if they need to bewashed.

Always use clean, low pressure water to wash dirty teats.

9.5 Check teat disinfectant mix, particularly emollientconcentrations.

The addition of 10% emollient, such as glycerine, to teatdisinfectant helps improve teat skin condition. If required,glycerine may be used at 20% for short periods – not morethan two weeks.

9.6 Check important machine factors.

Check vacuum level.

Check pulsators.

Check liner suitability.

9.7 Avoid the use of teat ointments, especially those thatcome in tubs or jars.

Teat ointments which are dispensed by repeated dipping into ajar become easily contaminated with bacteria and may spreadinfection.

9.8 Seek advice from your veterinarian if problems persist.

10 Rapidly find, treat andrecord clinical cases

nnnnn abnormal milknnnnn checking suspect cowsnnnnn clots on milk filternnnnn foremilk stripping

nnnnn increased Bulk Milk CellCounts

nnnnn milk samples for culturennnnn swollen quarters

Throughout lactation, milking staff must keep a close watch for mastitis cases. Finding cases can

sometimes be a challenge, especially in large herds, but the effort is worth it.

If clinical mastitis cases are missed, they pour millions of cells into the vat and can significantly

increase Bulk Milk Cell Count. Rapid detection and treatment of cases means fewer chronic

infections develop, and there is less chance of infection being passed to other cows.

A case of clinical mastitis which requires treatment occurs when there is heat, swelling or pain in

the udder, or there are changes in the milk (wateriness or clots) that persist for more than three

squirts of milk.

You need records of clinical cases and treatments to assess individual cows for culling and to

monitor herd mastitis. Your herd has a significant problem if there are more than five clinical

cases per 100 cows in the first month of lactation, or two clinical cases per 100 cows in

subsequent months of lactation.

Milk cultures are recommended to identify which bacteria are involved if a herd problem emerges.

A sterile sample must be taken before treatment is started for each case.

Bulk Milk Cell Counts, ðððððrefer page 7

GUIDELINE

10.1 Monitor daily Bulk Milk Cell Counts (if available).

A sudden increase may indicate one or more missed clinicalcases. If your Bulk Milk Cell Counts are usually less than200 000, a 10% increase may indicate a missed clinicalcase.

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ïïïïï Refer to Guideline 5.2 –foremilk stripping,page 27

Guideline 10Clinical cases

Checking the milk filter.

ïïïïï Refer to Guideline 12 – UseIndividual Cow Cell Countsfor management decisions,page 49

10.2 Check for swollen quarters and quarters that don’tmilk out.

Both cups-on and cups-off operators should be looking forswollen quarters at every milking. Cups-off operators maysee ‘strings’ of mastitis hanging from teat ends.

10.3 Watch for clots on the milk filter.

Check the filter after every milking, beforewashing the plant.

If there is a separate mastitis herd, check beforethese cows are milked.

Learning to assess the nature of the material on themilk filter (reading the filter) can be very useful.

If there are any clots on the filter, examine suspectcows at the next milking.

Check the filter again at the next milking. If clots are stillpresent, perform a close examination of all cows at thesubsequent milking.

10.4 If close examination of cows is required, check everyquarter of ‘suspect cows’ for clots before applyingthe machines.

Suspect cows include:

n cows which have not milked out

n cows which have recently had a case of mastitis (checkclinical records for last month)

n cows known to have had a high Individual Cow CellCount (check last Milk Recording sheet).

Stripping foremilk involves squirting a few streams of milkpreferably onto a black surface. Milk containing infectionmay be spread during this procedure, so avoid splashes orsprays of milk.

Gloves should always be used. Good milkers learn to stripwithout getting milk on their gloves.

Look for clots, watery or discoloured milk that persists formore than three squirts.

TIP: if you can’t checkevery quarter of every cowat one milking (becauseyou milk too many cows),spread the job over twomilkings. Check one side(eg left front and backquarters of every cow) atone milking, and the otherside (right quarters ofevery cow) at the next.

Guideline 10Clinical cases

Strep agalactiae, refer ðððððpage 3

Hand-held conductivity ðððððmeters , refer page 9

Refer to Fact Sheet A – ðððððMilk cultures, on page 87

Refer to Guideline 4 –Rapidly find, treat and

record clinical cases infreshly calved cows,

page 20, and ðððððFact Sheet E – Records

to keep on clinical casesof mastitis, page 97

Refer to Guideline 5 – Use ðððððgood milking technique

and a consistent routine,page 27

Quarters with a few small flecks only in the first threesquirts may be left untreated and checked again next milk-ing. If these flecks continue every milking, consider taking amilk sample for culture and check the Individual Cow CellCount history.

Current knowledge does not support the use of Rapid MastitisTest, Individual Cow Cell Counts or hand-held conductivitymeters to identify clinical cases for treatment.

For cows that are not sick, treatment during lactation shouldonly be used when there are visible changes present in themilk (or if Strep agalactiae is the infecting bacteria, inwhich case you should consult with your veterinarian).

10.5 Check every quarter of every cow for abnormal milkbefore applying machines in the next milking, if thecause of the clots is not found in the suspect cows.

Use the technique for stripping foremilk described in Guide-lines 5.2 and 10.4. If in doubt, recheck the cows again nextmilking.

10.6 Send milk samples for culture to establish theorganisms involved in the herd, if concerned by thenumber of cases.

If you have had more than two cases per 100 cows permonth in the past two months, or are concerned about thetype of clinical cases of mastitis occurring, it is worthwhilechecking the organism involved.

Samples for mastitis culture can be frozen and stored, sotaking samples from all cases and freezing them allows youto send them for laboratory examination later, if necessary.Frozen storage of more than about four weeks reduces thechance of obtaining a positive culture result.

10.7 Treat and record clinical cases as recommended bythe guidelines in this Countdown Downunderpublication.

10.8 Consider daily foremilk stripping, especially at high-risk times such as during outbreaks of clinical cases.

FACT Sheet reference needed!

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11 Monitor Bulk MilkCell Counts

nnnnn checking trendsnnnnn clinical casesnnnnn seeking advice

The BMCC is an indirect way of estimating the level of

subclinical mastitis in the herd. Each 100 000 cells/mL

indicates approximately 10% of cows are infected.

A series of BMCCs should be assessed to see both the level

and the trend for a herd.

In herds with BMCCs below 200 000, a sudden increase (of 10%

or more) may indicate that a clinical case has been missed.

Herds with higher BMCCs have much more fluctuation of

BMCCs on a day-to-day basis because there are so many

infected quarters.

ïïïïï Bulk Milk Cell Count,refer page 7

GUIDELINE

11.1 Check Bulk Milk Cell Counts whenever they arrive, tosee if they have risen.

Ask your factory to send each Bulk Milk Cell Count as soonas it is available.

Use a graph to help watch out for rising trend changes.

11.2 Consult with your factory field officer or veterinarianif close to, or in receipt of, Bulk Milk Cell Countswhich would downgrade milk.

11.3 Check for clinical cases – undetected clinicals cancause Bulk Milk Cell Counts to rise.

If your Bulk Milk Cell Counts are usually less than200 000/mL, a 10% increase may indicate a missed clinicalcase.

As you receive Bulk Milk Cell Counts from your factory, plot themon a graph like this one.

This graph shows a ‘spike’ in September and a worrying trend ofincreasing BMCCs from December. If your graph shows this typeof trend, consult with your factory field officer or veterinarian.

Guideline 11Monitoring BMCCs

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12 Use Individual CowCell Counts formanagement decisions

nnnnn chronically infected cowsnnnnn infection spread

nnnnn seeking advicennnnn monitoring heifers

ïïïïï Strep agalactiae, referpage 3

GUIDELINE

ïïïïï Selective Dry CowTreatment , refer page 18

ïïïïï Bulk Milk Cell Count ,refer page 7

Chronically infected cowshave multiple ICCCsabove 250,000 cells/mL.

Regular ICCCs enable you to monitor udder health over each

lactation. They also give you an option for Selective Dry Cow

Treatment , and allow you to assess the contribution of

individual cows to Bulk Milk Cell Count problems if they arise.

Recent Australian evidence shows that it is not economic to

treat high cell count cows with antibiotics during lactation,

unless these cows have Strep agalactiae infections.

12.1 Consult your veterinarian or factory field officer foradvice on management of cows contributing highnumbers of cells to the vat, if Bulk Milk Cell Countpremiums are being lost or you are approachingpenalty levels.

Management options may include:

n using high cell count cows to feed calves

n strategic culling

n drying off cows or quarters

n treatment if Strep agalactiae is identified as a problemin the herd.

12.2 Consider milking chronically infected cows last toavoid contaminating other cows.

Staph aureus, refer page 3 ððððð

Guideline 12Using ICCCs

12.3 Watch for evidence of spread of infection in the herdby checking the percentage of cows and heifers withincreased cell counts each month.

Heifers are likely to be clean of contagious mastitis bacteriaat calving, and so can be an ‘indicator group’ for spread ofinfection.

Cell counts are a guide to infection status of individualanimals, and will only give a guide to infection spread.Where contagious mastitis bacteria are concerned (espe-cially Staph aureus) fluctuations in cell count occur ininfected animals, and a peak cell count over the seasonshould be used. A reduction in cell count in tests later inlactation does not necessarily mean that the infection hascleared up.

In herds with satisfactory mastitis control, no more than 1%additional heifers should have a peak ICCC of greater than250 000 cells/mL each month.

For example, if 10% of heifers have a peak cell count ofgreater than 250 000 cells/mL in November, no more than11% should have a peak cell count of 250 000 cells/mL byDecember.

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13 Seek professional adviceif problems persist

nnnnn acting on warning levelsnnnnn preventative actionnnnnn recording problems

Assistance in investigating and solving mastitis and milk

quality problems is available in all dairying regions. A team

approach is often required because solutions require the

expertise of a number of professionals. Countdown

Downunder is providing training in these skills for

veterinarians, milking machine technicians and dairy field

officers throughout Australia.

GUIDELINE

Factor W arning level, seek helpYour

figures

Bulk Milk Average for past six months above250,000 cells/mL---------------------- OR ----------------------More than five consecutive 10-dayperiods above premium threshold

Clinical More than five clinical cases per 100 cowscase rate in the first month of lactation

---------------------- OR ----------------------More than two clinical cases per 100 cowsin subsequent months of lactation

Cultures The presence of Strep agalactiae

Individual More than 1% extra cows and heifers haveCow Cell peak cell counts over 250,000 cells/mLCounts each month

Teat Is unacceptable and does not improvecondition three weeks after changes are made to

machines or disinfectant mix.

13.1 Seek professional advice from your veterinarian,factory field officer or AMMTA-qualified milkingmachine technician if mastitis indexes are abovewarning levels.

Seek advice and put into action the advice you are given.

13.2 Record problems and actions taken.

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LATE LACTATION

Last 2–3 months of lactation.Continue all recommendations from lactationperiod and the following:

Guideline Page

14 Decide dry cow mastitis strategy –drying off dates and Dry CowTreatment 55

15 Cull persistently infected cows 58

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Decide dry cow mastitisstrategy – drying-off dates,and Dry Cow Treatment

14nnnnn blanket DCTnnnnn collecting datannnnn dates to dry-offnnnnn DCT choice

nnnnn DCT storagennnnn high cell count cowsnnnnn selective DCTnnnnn veterinary advice

Drying-off datesAfter each lactation, dairy cows require a dry period which is

sufficiently long to allow the udder tissue to repair and

rejuvenate. Many of the cells that produce milk are removed

and replaced again before the next calving. A minimum of six

weeks (preferably eight weeks) is recommended between

drying-off and calving.

GUIDELINE

ïïïïï Bulk Milk Cell Counts,refer page 7

14.1 Use expected calving dates to make a list of drying-off dates, ensuring that all cows get at least sixweeks (preferably eight weeks) dry period.

In seasonal herds it is often practical to plan to dry-offbatches of cows.

14.2 Consider drying-off high cell count cows early tohelp lower Bulk Milk Cell Counts.

These cows may jeopardise milk quality, especially inseasonal herds.

Other considerations (e.g. body condition score, productionlevels, feed availability) may also indicate that earlierdrying-off dates are appropriate for some cows.

Use Dry Cow Treatment in these high cell count cows ifthey are to be kept for the next lactation.

Guideline 14Dry cow strategy

Individual Cow Cell ðððððCounts, refer page 6

Refer to Fact Sheet C – ðððððGuide to the choice of

Selective or Blanket DryCow Treatment, page 93

14.3 Collect data to assess herd mastitis level.

You will require:

n Bulk Milk Cell Counts for the last six months

n Individual Cow Cell Counts. At least three ICCCs areneeded, spread through the current lactation for allcows to be dried-off. It is unreliable to use milk record-ing ‘spot test’ to select Dry Cow Treatment

n records of clinical cases.

14.4 Plan to use Dry Cow Treatment in all appropriatecows in the herd.

Use Selective Dry Cow Treatment if possible, or BlanketDry Cow Treatment if necessary. Seek advice from yourveterinarian.

Dry Cow TreatmentDry Cow Treatment is used to:

nnnnn treat existing infections which have not been cured during lactation

nnnnn reduce the number of new infections which may occur during the dry period.

Dry Cow Treatment is a formulation of antibiotic prepared for administration into the udder

immediately after the last milking of a lactation. It is designed to remain in the udder in

concentrations high enough to kill mastitis bacteria for a period which depends on the product

used (usually between 20 and 70 days). The prolonged time of exposure to antibiotic and the

formulation enhance penetration and give an increased chance of curing infections embedded

deep in the udder.

Dry Cow Treatment also protects udders from new infections in the dry period. Research in New

Zealand has shown that this occurs directly through the antibiotic presence soon after drying-off,

and indirectly by promoting the formation of the natural keratin plug which seals the teat canal.

Dry Cow Treatment products do not protect against some environmental bacteria which may be

introduced into the udder if administration is not done very cleanly. These environmental bacteria

may cause severe clinical mastitis.

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Note: At the time ofpublication there wasinsufficient information tomake recommendationsabout the use of non-antibiotic intramammaryproducts (such as ‘TeatSeal’) at drying-off.

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Guideline 14Dry cow strategy

If using Blanket DCT, treat all quarters of all cows.

If using Selective DCT, treat all quarters of all cows with apeak ICCC of above 250,000 cells/mL during the currentlactation, and all cows which have had a clinical case in thecurrent lactation.

Do not omit to treat first lactation cows if indicated – theyhave the best cure rates.

Do not treat cows which are to be culled after drying-off.

14.5 Choose the Dry Cow Treatment product to be used –consult your veterinarian.

Your veterinarian will help you assess factors such as:

n previous culture results and antibiotic responses on yourproperty

n published cure rates of products for existing infections

n claimed period of protection of products for new infec-tions

n minimum dry periods of products and anticipated dryperiod lengths of cows.

14.6 Purchase and store the Dry Cow Treatment you willneed at drying-off.

Purchase the required number of tubes for all quarters of allcows to be treated.

Store in cool, clean environment, preferably in a refrigera-tor.

Do not store Dry Cow Treatment near tubes of LactatingCow antibiotic. This reduces the risk of accidental adminis-tration of DCT to milking cows.

Ensure you have methylated spirits and cotton balls, ordisinfectant teat wipes to disinfect teat ends.

15 Cull persistentlyinfected cows

nnnnn high cell count cowsnnnnn problems in consecutive

lactations

Culling cows is the only way to eliminate some infections. It

reduces bacterial challenge to clean cows, and may have a

significant impact on Bulk Milk Cell Counts .

Despite long action and formulation to maximise penetration,

Dry Cow Treatment does not cure all existing infections. Many

studies worldwide have established that cure rates are lower

for older cows with chronic infections. Some particular

bacteria are also very difficult to treat successfully in all age

groups.

Culling infected (particularly older) cows is a key strategy in

mastitis control. Chronically infected cows are likely to be a

source of bacteria for other cows. Culling cows with chronic

infections helps protect the healthy, young cows which are the

future of the herd.

A small number of high cell count cows can have a significant

effect on Bulk Milk Cell Count level and milk quality payments.

A decision to cull these cows should be based on economics –

loss of net milk yield versus gain in milk quality payment

(BMCC premium).

Although culling is important in mastitis control, it is an

expensive option. Farm cell count problems are seldom solved

by culling alone. Failure to prevent new infections will mean

that other cows take their place at the top of the high cell

count list.

GUIDELINE

Dry Cow Treatment, ðððððrefer page 8

Bulk Milk Cell Counts, ðððððrefer page 7

nnnnn recurrent clinical cases

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15.1 Consider culling any cow when you find her thirdclinical case for this lactation.

If only one quarter is involved, you may prefer to dry-offthat quarter and milk the cow as a ‘three teater’, but thesecows increase the risk of errors in cup application at milk-ing.

Ensure that cows with three clinical cases (per cow) duringthe current lactation have been considered on the cullinglist.

Do not use Dry Cow Treatment on cows which you aregoing to cull.

15.2 Consider culling cows with high cell counts in twoconsecutive lactations, despite treatment with DryCow Treatment in the dry period in between.

If strategic (voluntary) culling is possible in the herd, in-clude cell counts as a factor to be assessed.

Cows to consider for culling are those which are unlikely tocure. For example, cows which have had high cell countsthroughout two consecutive lactations (despite receivingDry Cow Treatment in the dry period between). Other issuessuch as age, level of production and reproductive statusmust also be considered for each cow.

A high cell count is greaterthan 250,000 cells/mL.

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Guideline 15Culling

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One week before drying-off to one week after

Guideline Page

16 Dry-off abruptly taking steps toreduce yield to between 5 and 12 L/day 63

17 Administer Dry Cow Treatment asrecommended 65

18 Check udders each day for a week 68

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Dry-off abruptly takingsteps to reduce yieldto between 5 and 12 L/day

16nnnnn drying-off areasnnnnn last milking datesnnnnn maintaining water supplynnnnn manipulating diet

nnnnn reducing yieldsnnnnn teat canal sealingnnnnn yields below 5 L

ïïïïï Cow-associated mastitis,refer page 3

ïïïïï Environmental mastitis,refer page 4

GUIDELINE

ïïïïï Bulk Milk Cell Count,refer page 7

As cows near the end of lactation their milk quality changes. Milk

from low-producing cows may cause processing problems for

some dairy products. Cows producing less than five litres per day

may have an elevated cell count even if uninfected. They may

contribute to a higher Bulk Milk Cell Count (especially in seasonal

herds), even though their milk volume is low.

Udder infections during the dry period can be minimised by events

at drying-off. The aim is to shut down milk secretion and seal the

teat canal as rapidly as possible – this sealing usually takes about

two weeks. Studies in New Zealand have shown that virtually all

new infections occur in quarters where the teat canal has not

sealed.

Intermittent milking provides an on-going stimulus to produce milk

and impedes teat sealing. If ‘skip-a-day’ milking is practised,

mastitis risk is greatly increased.

During the first two weeks after drying-off, it is also important to

minimise the number of bacteria that contaminate the teats.

Teat dipping after the last milking ensures complete coverage of the

teat by disinfectant and reduces the number of cow-associated

mastitis bacteria present on the skin.

To reduce the number of environmental mastitis bacteria, areas

where cows lie should be as clean as possible, with no bare ground

or heavy manure soiling. Outbreaks of Pseudomonas mastitis have

been recorded in situations where cows lie in wet conditions in the

first few days immediately after drying-off. These infections may be

very severe (often fatal) and are virtually impossible to treat.

Refer to ‘Reducing yields’ ðððððabove

Refer to Guideline 17 – ððððð Administer Dry Cow

Treatments asrecommended, page 65

Guideline 16Drying-off

Reducing yieldsOne week prior to the finalmilking date:nnnnn stop feeding allconcentrates.

Three days prior to thefinal milking date:nnnnn Move to a paddock with

very little feed.nnnnn Reduce feed intake to

maintenance level egapprox 7–8 kg hay for acow weighing 500 kg.

nnnnn Separate the cows fromthe main herd if practical.

nnnnn Change routine formilking if practical egbring the cows to themilking area through adifferent entry.

Animal welfare codesrequire that water isavailable throughout.

16.1 Dry-off cows as soon as their production reaches 5 Lor less per day.

16.2 Cease milking cows producing 12 L or less per day atdrying-off.

16.3 Take steps for cows producing more than 12 L/day, toreduce production to 12 L or less by the drying-offdate. These steps involve reducing food intake andchanging routine.

Decide the date of the final milking for target cows.

Start preparation for drying-off at least a week before dateof final milking.

16.4 Dry off abruptly; do not skip days and preferably donot skip milkings.

Milk out as usual at each milking until drying-off.

Do not deliberately leave some milk in the udder (undermilk). It is not necessary to leave milk in the udder at thelast milking to improve the action of Dry Cow Treatment.

At the last milking:

n Milk out as usual.

n If Dry Cow Treatment is to be used, administer it asrecommended by Countdown Downunder.

n Cover whole surface of teat in freshly prepared teatdisinfectant (dip is preferable to spray).

16.5 Don’t leave cows in laneways or yards immediatelyafter drying-off.

Avoid allowing them to lie down on bare ground or areasthat are soiled with manure in the two hours immediatelyafter you give Dry Cow Treatment.

16.6 Put the cows in a dry, clean paddock (not heavilysoiled with manure, no bare ground, no exposure todairy effluent) for 3–4 days after drying-off.

This paddock should be well away from the milking herdand the milking area, so cows don’t have the stimulus to letdown milk.

16.7 Continue the ‘maintenance only’ diet for another3–4 days for cows that were producing 12 or morelitres/day in the week before drying-off.

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Administer Dry CowTreatments asrecommended

17nnnnn avoiding injuriesnnnnn disinfecting teat endsnnnnn drying-off environment

nnnnn recording treatmentnnnnn udder markingnnnnn withholding periods

Administration of Dry Cow Treatment has some hazards, for cows and operators. It is critical that

it is carried out properly.

It is easy to introduce bacteria into the teat if the teat end is not disinfected properly, or it is

contaminated before it has sealed. Infection with environmental bacteria can cause severe

mastitis.

Operators can be injured by cows during administration of Dry Cow Treatment; it is important to

take time and have help.

Antibiotic residues in milk and meat (including calves) must be avoided by observing the

minimum dry periods and withholding periods after calving which are specified for each product.

This is particularly important where cows are culled during the dry period, or calve earlier than

expected.

GUIDELINE

17.1 Plan for the time and effort that treating cows withDry Cow Treatment takes. Administration of Dry CowTreatment is a critical and difficult job. Ensure thatresponsible operators are trained adequately in theprocedure and supervised well.

To do a good job with Dry Cow Treatment, one person canonly handle about 20 cows per hour.

More than one person is often needed to do the job well andreduce the hazards associated with the procedure, especiallyif cows are not used to having their teats handled.

Select reasonable sized groups of cows to be treated afterany one milking, especially in seasonal herds.

Refer to Guideline 14 – ðððððDecide dry cow mastitis

strategy, page 55

Refer to Fact Sheet C – ðððððGuide to the choice of

Selective or Blanket DryCow Treatment, page 93

Refer to Fact Sheet B – ðððððThe correct way to give

intramammary treatments, page 91

Guideline 17Dry Cow Treatment

If practicable, at the previous milking, draft out the nextbatch of cows to be treated. Milk and treat these cows beforebringing the remainder of the herd through the dairy. Thisensures maximum cleanliness of the plant at the time oftreatment.

Wash out the dairy between batches of cows if severalbatches are to be treated after one milking.

17.2 Treat all cows if using Blanket Dry Cow Treatment. Ifusing Selective Dry Cow Treatment, treat all cows withany ICCC above 250 000 cells/mL during the lactation,and any cow which has had a clinical case during thelactation.

17.3 Do not use Dry Cow Treatment on cows that are to beculled.

17.4 Use Dry Cow Treatment only at the cow’s last milkingfor the current lactation.

Dry Cow Treatment is registered only for use immediatelyafter a cow’s last milking for a lactation. Off-label use isstrongly discouraged because drug residue risks increase andcure rates are likely to be reduced.

17.5 Administer the treatments as recommended ensuringthe teat ends are sanitised properly.

17.6 Treat all quarters of cows to receive Dry CowTreatment (except quarters that have been dried offfor some time in cows milked as ‘three teaters’).

If a quarter is dry, absorption of the Dry Cow Treatment inthe quarter will be changed. Off-label use is strongly dis-couraged because drug residue risks increase and cure ratesare likely to be reduced. Injectable antibiotics may be usedin these cases – consult with your veterinarian.

17.7 Dip teats with freshly made up teat disinfectant aftertreatment.

Even if you usually spray, dipping is preferable after DryCow Treatment to ensure complete coverage of the teat.

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Guideline 17Dry Cow Treatment

17.8 Mark the udder (e.g. with a spray paint) so that cowsthat have received Dry Cow Treatment can be easilyrecognised.

This allows easy recognition if cows rejoin the herd in error.

17.9 Record cow ID, date and product details of all DryCow Treatments.

If cows calve early, or a decision to cull them during the dryperiod is made, the date of treatment and the withholdingperiod of the particular product must be known.

For each batch of cows treated, mark the earliest calvingdate allowable for the meat withholding period and mini-mum dry period to pass. Calves born before this date maycontain antibiotics, whether they have sucked or not. Theyshould not be sold for slaughter until the meat withholdingperiod for that product has elapsed. Check the label.

17.10 Don’t leave cows in laneways or yards immediatelyafter Dry Cow Treatment.

Avoid allowing them to lie down on bare ground or areasthat are soiled with manure in the two hours immediatelyafter you give Dry Cow Treatment.

17.11 Put the cows in a dry, clean paddock (not heavilysoiled with manure, no bare ground, no exposure todairy effluent) for 3–4 days after Dry Cow Treatment.

This paddock should be well away from the milking herd. Itis essential that cows treated with Dry Cow Treat-ment are not able to rejoin the herd in error. Ifthey enter the dairy they will probably let-down milk (reducing teat plug formation)and may have the cups put on, leading toantibiotic contamination of the vat milk.

17.12 To minimise milk and antibioticleakage, do not walk cows long distancesfor 3–4 days after Dry Cow Treatment isadministered.

18 Check udders each dayfor a week

nnnnn clinical quartersnnnnn manual check

nnnnn swollen quartersnnnnn veterinary advice

Cows are susceptible to new infections particularly in the first

week of the dry period before their teats have sealed.

These infections must be identified and treated so that they do

not persist and create problems after calving. Remember,

however, the objective is to achieve teat plug formation

quickly.

GUIDELINE

18.1 Look at udders of all cows for swollen quarters(larger than other quarters on the same cow), whilecows are in the paddock.

Avoid bringing cows near the dairy area (or they may startrunning milk).

Observe every day for a week.

Do not handle – just look.

If a quarter is swollen, bring the suspect cow into the dairyarea and check the udder manually.

18.2 Check swollen quarters manually.

Check for heat and pain – compare between all quarters.

Strip secretion from suspect quarter and check. It may bedifferent from milk prior to drying off (e.g. thicker and more‘stringy’) and therefore difficult to assess.

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ïïïïï Oxytocin, refer page 11

Guideline 18Checking udders

ïïïïï Dry Cow Treatment, referpage 8

If suspicious, treat as a clinical case.

Do not remove milk or secretion from adjacent normalquarters.

18.3 Treat clinical quarters by stripping out completelyand using a full course of lactation antibiotic.

Veterinary advice is recommended.

Use Lactating Cow intramammary antibiotic (even if DryCow Treatment was previously used in the quarter).

Use the full course of the antibiotic (as recommended on thelabel).

Strip out completely and continue to strip out at least twiceevery day during the course of the treatment.

Avoid using high doses (greater than 3 mL) of Oxytocin inlate pregnant cows.

Injectable antibiotic may be appropriate.

Record clinical details.

18.4 Treat again with Dry Cow Treatment and amendrecord of date for Minimum Dry Period when the caseis resolved.

For clinical cases that occur in the first week after dryingoff, re-treatment with Dry Cow Treatment is advised.Consult with your veterinarian.

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DRY PERIOD

Guideline Page

19 Observe cows weekly 73

20 Selling cows – check withholdingperiods 74

21 Buying cows – check cell count andtreatment histories, examine udders 75

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19.1 Observe cows regularly (each week) during the dryperiod.

Observe udders for signs of swollen quarters when carryingout normal observation of dry cows.

If quarters look swollen, bring in and check udders manu-ally.

19.2 Check swollen quarters manually.

Check for heat and pain – compare between all quarters.

Strip secretion from suspect quarter and check. It may bedifferent from milk prior to drying–off, and therefore diffi-cult to assess.

If suspicious, treat as a clinical case. Do not remove milk orsecretion from adjacent normal quarters.

Do not repeat the use of Dry Cow Treatment in these quar-ters – withholding periods may exceed the remainder of thedry period time.

19 Observe cows weekly

n antibiotic treatmentn manually check swollen quartersn watch for swollen quarters

GUIDELINE

Dry cows should be checked regularly for changes in the udder

because clinical cases can occur during the dry period and

quarters that are not treated may have lower production in the

next season. Visual observation of udder size and symmetry is

all that is required, and often all that is possible where dry

cows are kept. Some facilities for handling suspect cows are

essential.

ïïïïï Refer to Guideline 4 –Rapidly find, treat andrecord clinical cases infreshly calved cows,page 20

Swollen quarter in a dry cow.

20 Selling cows – checkwithholding periods

n selling for meat

Local and overseas consumers demand ‘clean beef’, free from unacceptable chemical residues.

Cows culled from our dairy herds must be free from all unacceptable residues when they are sold

for slaughter. Errors have the potential to jeopardise Australia’s beef export trade (two-thirds of

our beef production and worth $2.6 billion a year).

All cows must be identified if treated with any antibiotic. Dairy farmers tend to maintain markings

which can be easily seen on cows during the milk withholding period, but not for the full length of

the meat withholding period. They generally rely on permanent identification and written records

to check when meat withholding periods have expired.

It is essential to keep records of all treatments and check these for every cow that is to be sold.

Withholding period, ððððð refer page 12

GUIDELINE

20.1 Check withholding periods.

Do not sell for meat unless the antibiotic withholdingperiod for meat has passed.

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21 Buying cows – check cellcount and treatmenthistories, examine udders

n BMCC historyn buying heifersn checking cowsn DCT history

n ICCC historyn introduced cowsn milk sample culture

One of the most common ways of introducing the cow-

associated mastitis bacteria into a herd is in the udders of cows

that are bought in. Bacteria such as Strep agalactiae can spread

rapidly through a herd – it is better not to introduce the bacteria

in the first place.

GUIDELINE

ïïïïï Strep agalactiae , refer page3

ïïïïï Bulk Milk Cell Counts, referpage 7

ïïïïï Individual Cow Cell Counts,refer page 86

21.1 Buy heifers before first calving (rather than cows),where possible.

It is likely (although not certain) that a heifer that has neverbeen in another dairy area will be free of the major bacterialcauses of mastitis.

21.2 Don’t buy cows unless the Bulk Milk Cell Counts fromthe herd of origin are available.

If the average BMCC for the past six months is less than200,000 cells/mL, it is unlikely to be a Strep agalactiaeherd.

21.3 Don’t buy cows unless they have Individual Cow CellCounts.

Don’t buy cows with any cell counts above 250,000 cells/mL.

Be especially wary of older cows.

Refer to Fact Sheet A – ðððððMilk cultures, page 87

Guideline 21Buying cows

Dry Cow Treatment, ðððððrefer page 8

Refer to Guideline 5.2 – ðððððForemilk stripping,

page 27

21.4 Ask about Dry Cow Treatment history.

If cows have received Dry Cow Treatment, you shouldknow the product used and the date of treatment.

21.5 Check cows before buying them.

Feel udders for uneven consistency or lumps.

Look at teats for teat sores or damage.

If lactating, check foremilk by stripping milk, preferablyonto a black surface, and definitely not onto your hand.

21.6 Check new cows again before milking them with theherd.

Feel udders for uneven consistency or lumps.

Look at teats for teat sores or damage.

Check foremilk by stripping milk, preferably onto a blacksurface, and definitely not onto your hand.

Milk containing infection may be spread during this proce-dure, so gloves should always be used, and hands washed inrunning water between cows.

If abnormalities are detected, have a milk sample cultured.

21.7 Consider having a milk sample cultured even if noabnormalities are found when you check the udder.

A milk sample (containing an equal portion of milk fromeach quarter) is very likely to show Strep agalactiae if it ispresent. The cost of the culture is likely to be a good invest-ment.

If Strep agalactiae is found, segregation and treatment isadvised.

Consult your veterinarian for more advice.

21.8 Milk introduced cows last until you are confident thatthey are free of mastitis.

21.9 Don’t milk other people’s cows with your herd.

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REVIEW ANDPLANNING

Each herd to set a specific time that suits

Guideline Page

22 Set a time to do annual mastitiscontrol activities and reviewachievements 79

23 Sign on for milk recording – IndividualCow Cell Counts are a keymanagement tool 80

24 Review Countdown Downunderrecords 81

25 Test, service and up-grade milkingmachines 81

26 Service teat spray units and reviewteat disinfectant which is to be used 82

27 Fix areas that make udders muddy 83

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nnnnn involve everyone

22 Set a time to do annualmastitis control activitiesand review achievements

nnnnn set time aside

GUIDELINE

Each year, time must be set for mastitis program activities

affecting the whole herd or milking system. This set time may

be the dry period for all cows in seasonal herds, or a

convenient period in year-round herds.

ïïïïï Refer to Guideline 25.2 –Use a milking machinetechnician who tests toAMMTA standards, page 81

ïïïïï Refer to Guideline 25 –Test, service and upgrademilking machines, page 81


22.1 Mark ‘a day in the office’ on your calendar ordiary. Set time aside well in advance.

22.2 Involve all members of staff and family workingon the farm in developing and reviewing mastitiscontrol activities and achievements.

Consider also involving your factory field officer andveterinarian.

22.3 Make an appointment with your milking machinetechnician for testing, servicing and (wherenecessary) upgrading your milking system.

Make the appointment well in advance. The technicianshould be qualified.

Your milking machine should be fully tested and serviced atleast once a year.

In addition, it should be monitored, tested and adjusted asoften as necessary during lactation.

23–27 Review and planningchecklists

nnnnn milk recordingnnnnn milking machinesnnnnn muddy areas

nnnnn review recordsnnnnn teat spray unitsnnnnn teat disinfectant

Sign on for milk recording (herdtesting) – ICCCs are a keymanagement tool

23

Guidelines 23 to 27 have been combined to make a ‘to do’ list for

you to use during the review and planning period. A space has

been provided for you to tick and date each activity when it has

been completed.

done

Refer to Guideline 12 – ðððððUse ICCCs for

management decisions, page 49

GUIDELINES

Good management requires information. Without records ofclinicals and subclinicals revealed by cell count data, mastitisis an invisible disease.

By milk recording you can access valuable information aboutlate lactation yield to aid drying-off decisions, have IndividualCow Cell Counts and keep records of clinical cases.

Regular ICCCs enable you to monitor udder health over alactation, give you an option for Selective Dry Cow Treat-ment, and allow you to assess contribution of individual cowsto Bulk Milk Cell Count problems if they arise.

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Testing, servicing and upgrading milking machines is abso-lutely essential.

Virtually all infections enter the udder through the teat open-ings.

Your milking machine spends a total of 50–100 hoursattached to each teat in a lactation. Machine malfunctionscause teat damage and increase risk of infection.

25.1 Fully test and service your milking machine atleast once per year.

In addition, it should be monitored, tested and adjusted asoften as necessary during lactation.

25.2 Use a milking machine technician who teststo AMMTA standards.

Make sure the technician performs the tests according toAMMTA (Australian Milking Machine Trade Association)standards. Guideline 22.3 advised that you confirm this beforemaking the booking and the technician should preferably havea current AMMTA qualification and/or have completed aCountdown Downunder accredited continuing educationcourse.

Review Countdown Downunderrecords

24done

Test, service and upgrademilking machines

25done


Guidelines 23–27Checklists

ïïïïï Refer to Guideline 13.1 –Seek professional advicefrom your veterinarian,factory field officer orAMMTA qualified milkingmachine technician ifmastitis indexes are abovewarning levels, page 51

24.1 Calculate the figures for your farm in the past12 months, and set targets for the next 12months.

24.2 Seek advice if farm indexes are above thewarning levels.

25.3 Insist that the technician provides andexplains a full written report.

An AMMTA test report form provides a summary on the firstpage, and full details of milking machine performance beforeand after adjustment. The report should compare your ma-chine performance against the current AMMTA recommenda-tions.

The technician should explain the details of the report to you.

25.4 Carry out all recommendations.

Make a plan with a schedule which will fit in with workcommitments and cash flow. Don’t put off making your planfor some other time.

You may also find it useful to discuss the plan with your othermilk quality advisers (your factory field officer, veterinarianor other milk harvesting specialist).

Refer to Fact Sheet F – ðððððAMMTA milking machine

test report form example,page 99

26doneService teat spray units and

review teat disinfectant which isto be used


26.1 Clean and check teat spraying equipment.

26.2 Review teat disinfectant and method ofapplication to be used.

Factors to consider include:

n previous experience on the property (including handskin reactions, teat skin condition)

n published effectiveness of products

n how much you want to be able to see the teat disinfect-ant on the teats after application – some products arecoloured and easier to see

n price (taking account of dilution – larger volume prod-ucts may not be as cost-effective as smaller volumes ofstock solution when diluted to the recommended con-centrations)

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done27 Fix areas that make udders

muddy


ïïïïï Refer to Fact Sheet G– The correct wayto mix teatdisinfectant, page 103

27.1 Clean and renovate areas around troughs,gates, laneways and the entrance to the dairyarea.

Adequate drainage and proper formation of lanes will de-crease problems with dirty teats and udders.

Don’t allow cows to enter dams, channels or other waterwaysto drink. If it is impossible to replace these water sources,limit access to the edge of a small pond area by fencing, andreinforce the bank with sleepers or wire grating.

n how the teat disinfectant is to be applied to teats – it iseasier to do a better job of covering teats by dippingthan spraying. Spraying typically uses twice as muchdisinfectant to get the same teat coverage.

FFFFFACT SHEETSACT SHEETSACT SHEETSACT SHEETSACT SHEETS

Fact sheet Page

A Milk cultures 87

B The correct way to give intramammarytreatments 91

C Guide to the choice of Selective orBlanket Dry Cow Treatment 93

D Guide to withholding periods afteruse of Dry Cow Treatment 95

E Records to keep on clinical casesof mastitis 97

F AMMTA milking machine test reportform example 99

G The correct way to mix teat disinfectant 103

H The impact of genetics on mastitisand cell counts 105

I The impact of nutrition on mastitisand cell counts 107

J The role of vaccination in mastitiscontrol 109

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A Milk cultures

What is milk culturing?

It isn’t possible to tell which bacteria are responsible for infections by looking at milk,udders or cell counts – you have to actually grow the bugs to know for sure.A milk sample can be processed in microbiology labs so that the bacteria that are present canbe identified. This involves the lab spreading some of the milk on sterile plates covered withparticular growth factors, incubating the plates for defined periods and assessing the bacterialcolonies that grow. This is called milk culturing.

The lab can also check which antibiotics are likely to be effective against each bacteria (called‘sensitivity testing’), but these tests only provide a guide because conditions in the lab arenever exactly the same as in the cow.

When is it worthwhile culturing milk samples from cows?

Milk cultures are recommended whenever a herd problem emerges – either more clinical casesthan acceptable, or rising cell counts. They are used to indicate which bacteria are presentwithin the herd, so samples from a number of cows (a minimum of 10) are required to give arepresentative picture.

Virtually all mastitis is caused by bacterial infection. It is essential to know which bacteria(e.g. Staph aureus, Strep agalactiae, Strep uberis) are present to choose where to look forproblems and select appropriate management strategies.

Cost is important but if a herd mastitis problem is emerging, the cost of the cultures is likely toonly be a small issue. Cultures vary from about $6 to $20 per sample depending on factorssuch as the number submitted at the same time and transport costs, etc.

Would you sample quarters with clinical mastitis?

Yes, in most cases it is a good insurance policy to take samples – but you won’t necessarilychoose to have them all cultured. You can collect them from all clinical cases beforetreatment (any antibiotic in the sample will make it very difficult to culture), store themfrozen and only submit them if a cow fails to respond to treatment, or there are a highernumber of cases than you expected (e.g. more than five clinical cases per 100 cows in the firstmonth of lactation).

FACT SHEET

Fact Sheet AMilk cultures

If you only end up having a couple of cases and they respond to treatment, you don’t need tosend the samples for culture, but if you do wish to investigate further, you’ve got some to startwith.

What about cows with high cell counts?

To investigate a herd cell count problem, it is sensible to sample some of the individual cowswith high cell counts. Here the sample is often a composite one (some milk from all fourquarters) and some infections will be missed because the bacteria from an infected quarter arediluted by milk from the others. To ensure you get results from at least 10 cows, it is worthtaking samples from a few extras.

Current research shows that it is not economic to treat lactating cows with high cell countscaused by Staph aureus infections, but infections with Strep bacteria are more responsive toantibiotic treatment and may be worth treating. Cultures are essential if you are contemplatingtreatments, and discussion with your veterinarian is recommended.

Are there any traps in milk culturing?

The main problems are associated with collection and transport of samples. Milk is a goodplace for contaminants to survive, and most of these bacteria can also cause mastitis, so veryconfusing results can occur if any contamination occurs. Spread of bacteria between cows canalso occur, so it is important to use gloves and disinfectant.

There is a specific procedure to follow to collect good quality samples. Bottles must be sterile(not just clean) and teat ends must be scrubbed with 70% alcohol to disinfect them adequately.You can get sterile containers from your vet or lab. The step-by-step guide below tells you howto collect the milk.

Ideally samples should be kept cool and arrive at the lab within 24 hours. If this isn’t possible,most mastitis bacteria survive freezing, so you can store them in the freezer until delivery.

Collecting milk samples

Sterile collection is the most important step for successful culturing of milk samples. Poortechnique will give misleading results and resampling will be required. A good techniqueinvolves planning and some patience.

nnnnn Have the following ready in the dairy:

o Sterile sample bottles. You can obtain these from your vet or lab. Sterile collectionrequires using only sterile bottles. It doesn’t matter how well washed a Vegemite jaris – it won’t do.

o A marker to label the bottle

o Disposable gloves

o Paper towels

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o Cotton balls

o A mixture of 70% alcohol (seven parts methylated spirits and three parts water) orteat wipes

o A cooled esky or similar portable and temporary cooling system.

nnnnn Label the bottle.

o Unlabelled samples are useless, so make sure you identify the sample.

o Do this before collection as it can be difficult to write on a label with milk sprayed onit.

o Use the marker pen to clearly label details of the sample – the date, your name, thecow’s ID, the quarter samples, and why the sample was collected.

nnnnn Restrain the cow so she can’t move around too much.

o Sometimes this is difficult on a platform, but do what is possible.

o Another person holding the cow’s tail as a ‘tail jack’ can be helpful.

nnnnn Put on disposable gloves.

nnnnn Wash and dry the teats.

o You might skip this step if the teats look clean.

o Wash the teats with running water. Avoid getting too much water on the udder – theudder is hard to dry, and drops of contaminated water can easily fall in the sample.

o Dry with a paper towel.

nnnnn Completely disinfect the end of the teats to be sampled. This step is critical.

o If you are sampling more than one teat, disinfect the ones furthest away first. Thisreduces the risk of unintentionally contaminating an already disinfected teat.

o Disinfect by vigorously scrubbing the teat opening with acotton ball and alcohol (or teat wipes) for a minimum of10 seconds.

o Check the cotton ball. If there is any dirty colour,repeat the scrub using a clean cotton ball until there isno more dirt seen.


nnnnn Get the sterile bottle ready.

o Remove the cap and place upside down in a position not likely to be contaminated.

o Do not touch the inside surface of the cap or bottle.

nnnnn Establish the direction of flow from the teat.

o Squeeze the first couple of squirts of milk ontothe ground.

o This also helps to remove any contaminants thatmight be just inside the opening of the teat.

nnnnn Collect the sample in the bottle.

o Hold the bottle at an angle (to avoid anythingfalling into it) at least 3–4 cm from the end of the teat.

o Squirt 2–4 mL of milk into the bottle. Only a small amount of milk is required forculture – trying to get a large sample increases the chance of contamination.

o If you are collecting a combined sample from all quarters, move the bottle away fromthe first teat and repeat the intial squirts of the next teat before moving the bottleback. Take the first samples from the teats closest to you. Try to get the same amountfrom each teat. (Note: a combined sample from all quarters may be less likely togrow bacteria because milk from one infected quarter is diluted by milk from theclean quarters.)

nnnnn Replace the cap and secure it tightly.

nnnnn Place the sample in the cooled esky.

nnnnn Wash your hands.

o Use running water and dry on paper towel.

o Wash your hands after each cow, including thelast cow.

nnnnn Deliver the sample to the vet or lab thatday, or freeze until delivery is arranged.

o Samples for mastitis culture can be frozen andstored before being sent to the laboratory.

o Frozen storage of more than four weeks reducesthe chance of obtaining a positive culture result.

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The correct way to giveintramammary treatments

It is easy to introduce bacteria into the teat with a treatment nozzle if the teat end is notdisinfected properly. Before any material is infused into a quarter, the teat end must bedisinfected very carefully. Infection with environmental bacteria can cause severe mastitis.

Operators can be injured by cows during administration of intramammary treatments. It isimportant to take time and have help. More than one person is often needed to do the job well,especially if cows are not used to having their teats handled.

nnnnn Have the following ready in the dairy:

o disposable gloves

o cotton balls

o a mixture of 70% alcohol (seven parts methylated spirits and three parts water) or teatwipes

o intramammary antibiotic tube(s). Keep the tube sterile; do not warm tubes by puttingthem in a bucket of warm water (this increases the chance of contamination); do notremove the tube cap until ready for use.

nnnnn Restrain the cow so she can’t move around too much.

o Sometimes this is difficult on a platform, but do what is possible.

o Another person holding the cow’s tail as a ‘tail jack’ can be helpful.

nnnnn Before infusing any antibiotic into a quarter, ensure thequarter is completely milked out.

nnnnn Ensure that your hands and the teats are clean anddry.

nnnnn Put on disposable gloves.

B

FACT SHEET

Fact Sheet BIntramammary treatments

nnnnn Completely disinfect the end of the teats to be treated. This step is critical.

o If you are treating more than one teat, scrub the ones furthest away first. This reducesthe risk of unintentionally contaminating an alreadydisinfected teat.

o Disinfect by vigorously scrubbing the teat openingwith a cotton ball and alcohol (or teat wipes) for aminimum of 10 seconds.

o Check the cotton ball. If there is any dirty colour,repeat the scrub using a clean cotton ball until there isno more dirt seen.

nnnnn If you are treating more than one teat, treat the onenearest you first, followed by treatment of the more distant teats.

nnnnn Insert the antibiotic tube into the teat canal.

o Remove the cap of the tube and, without touching its tip with your hand, gently insertthe nozzle into the teat canal.

o It is not necessary to insert the nozzle to its full depth – this can dilate the teat canalexcessively and predispose the cow to mastitis.

o The technique of only partially inserting the nozzle into the teat canal reduces teatend damage and has been shown in some trials to reduce the incidence of new infec-tions at calving.

nnnnn Infuse the contents of the syringe into the teat. Massage itup the teat into the udder.

nnnnn Teat dip treated quarters with freshly made up teat dipimmediately after treatment. Refer to Fact Sheet G onpage 103.

nnnnn Clearly mark the treated cow and treated quarter.

nnnnn Record all treatments on mastitis record sheet.

For more information about using Dry Cow Treatment, refer to Guideline 17 – AdministerDry Cow Treatment as recommended, on page 63.

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1 ððððð

2 ððððð

3 ððððð

4 ððððð

5 ððððð

6 ððððð

Yes

Yes

Yes

Yes

Yes

Yes

Use Blanket DryCow Treatment






C Guide to the choice ofSelective or BlanketDry Cow Treatment

FACT SHEET

If answers to all questions are‘No’, then use Selective DCT.

If the answer to any question is‘Yes’, then use Blanket DCT.

If using Blanket Dry Cow Treatment, treat all quarters of all cows. If using Selective Dry CowTreatment, treat all quarters of cows with any ICCC above 250,000 cells/mL during thelactation, and cows which have had a clinical case during the lactation.

Is your herd average BMCC for the last 6 monthsabove 250,000 cells/mL?

No

òòòòòDo more than 30% of your cows have peak ICCCsabove 250,000?

No

òòòòòDid you have more than five clinical cases per 100cows in the first month of lactation?

No

òòòòòDid you have more than an average of two clinicalcases per 100 cows per month after the first monthof lactation?

No

òòòòòDid you have more than two clinical cases per 100cows per month in either of the last two months oflactation?

No

òòòòòDo your milk cultures indicate the presence of Strepagalactiae or significant numbers of Strep uberis ?

No

òòòòòSelect cows for Dry Cow Treatment

Use the information here and consult your veterinarian for advice. If you have less thanthree Individual Cow Cell Counts (ICCCs) for each cow, use Blanket DCT. If you have three ormore ICCCs for each cow, and wish to consider selective treatment, proceed down thischart.

Fact Sheet CSelective or Blanket DCT

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Dry Cow Treatment (DCT) is an antibiotic preparation infused into each quarter immediately after thelast milking of a cow’s lactation. It is an important management procedure for removing existing udderinfections and preventing new infections during the dry period.

All DCT products are registered with a specified Minimum Dry Period (MDP) after treatment. If a cowcalves before this time has expired, withholding periods for milk and bobby calves are longer thanusual. These withholding periods (WHP) are shown on the product labels and in the table in this FactSheet.

Follow these guides to minimise risk of antibiotic residues in meat or milk after use of DCT:

nnnnn Ensure all cows to be culled have passed their recommended withholding periodfor meat.

o Withholding periods for cull cow meat are counted from the date the DCT is administered.

nnnnn Check each cow that received DCT has passed her Minimum Dry Period whenshe calves.

o If not, withhold milk from the vat and withhold the calf from sale for meat for the periodshown on the product label, and in the following table.

nnnnn Keep colostrum milk from all freshly calved cows out of the vat.

o For milk quality reasons, all cows should have their colostrum milk withheld from the vat forat least the first eight milkings after calving (10 milkings for induced cows). This applies toall cows whether they received DCT or not.

o For cows that did receive DCT (and their Minimum Dry Period has elapsed), a withholdingperiod for milk after calving is specified for each product (see labels and the following table).This withholding period for all current products is equivalent to or less than the eightmilkings of the colostrum mob. Colostrum milk from these cows should be fed to replace-ment calves only.

nnnnn Follow these guides for calves:

o Keep all calves for a minimum of four days (navels must be dry). Calves from induced cowsmay need to be kept for much longer before being sold.

Animal welfare codes require that all calves must be at least four days of age before beingsold. This applies to all calves, whether their dams received DCT or not.

o All calves should receive at least 2 L of colostrum in the first 12 hours of life.

D Guide to withholdingperiods after use ofDry Cow Treatment

FACT SHEET

Fact Sheet DWitholding periods DCT

Recommended withholding periods following use of each Dry Cow Treatment.

o Bobby calves whose dams had received DCT (and their Minimum Dry Period has elapsed)should be removed from their mothers after 12 hours and then fed milk. The milk shouldpreferably be from cows in the colostrum mob that did not receive DCT. Residues in bobbycalves are unlikely to occur as a result of intake of DCT in first sucked colostrum becauseabsorption from the gut is relatively poor for most DCT antibiotics, and the calves will be atleast four days old when sold.

After their calves are removed, cows that had received DCT should be milked out com-pletely, and this milk discarded or fed to replacement calves only.

nnnnn Have a milk sample tested by your factory before putting milk in the vat from aparticular cow you are concerned about.

o If you suspect an error in cow identity, or treatment or calving date records, don’t put themilk in the vat until the issue is resolved.

o Although milk antibiotic tests are not designed for use on milk from individual cows, a checktest will avoid the possibility of an inadvertent inclusion of positive milk. Request yourfactory to perform their regular test procedure for antibiotics in milk.

Figures in italic are not from material approved by the National Registration Authority (NRA), but provided by the

pharmaceutical companies, as consistent with NRA-approved WHPs in other products.Contact the manufacturing company, or your veterinarian for further information.

Withholding Withholdingperiod after period aftercalving if cow calving if cowcalves calvesBEFORE MDP AFTER MDP

Product Company Withholding Minimum Dry Milk Calf Milk Calfperiod after Period (MDP) WHP WHP WHP WHPtreatment for Welfaresale of cull cow codes– meat WHP requireDays Days Days Days Days Days

Albadry Plus Upjohn 30 30 14 30 3 4

Ampiclox Dry Cow Jurox 30 30 10 30 4 4

Cepravin Dry Cow Schering 21 56 Test 21 4 4Plough after 4

Elaclox DC Elanco 30 30 21 30 4 4

Elaclox DC Xtra Elanco 30 35 21 30 4 4

Neodry Upjohn 30 30 14 30 3 4Suspension

Noroclox Dry Cow Heriot 30 30 30 30 4 4

Orbenin Dry Cow Pfizer 30 30 21 30 4 4

Orbenin Enduro Pfizer 30 35 21 30 4 4

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E Records to keep on clinicalcases of mastitis

FACT SHEET

Mark cows with clinical cases of mastitis with a highly visible band, tape or paint.

Keep a temporary record of all current clinical cases of mastitis. The record should be clearand easy-to-see and located in the dairy for quick reference during milking. A whiteboard, forexample, displays information about cows for special handling (such as withholding milk).

It is also essential to keep permanent records of clinical mastitis cases. This record shouldinclude information about the cow and the drug used. This record allows you to:

o make better decisions for individual cows at drying off and culling times

o assess numbers of cases and responses to treatment for the whole herd. This is animportant part of monitoring udder health and mastitis control.

The Australian Dairy Herd Improvement Scheme (ADHIS) has established cow record detailsfor mastitis cases and treatments in its database. This means it is now possible to permanentlyrecord details of clinical cases through most of the Milk Recording services, and it is possibleto easily combine ICCC data and information about clinical cases for each cow. For moreinformation see your Herd Improvement service.

nnnnn Set up a record sheet in the milking shed, or a pocket book page to record thefollowing for each case:

Date

Cow identity

Quarter affected

Severity

Sample taken(Yes or No)

Treatment (Drug)

Number of tubes(mark a stroke for each asgiven e.g. I I I I )

Comment

Fact Sheet ERecords for clinicals

n Record these details when you first detect a case of clinical mastitis.

n If you are Milk Recording, use a system which allows you to have the dataincluded on your cows’ records.

o You may be entering your own records on a computer, or you may be able to sendthe records to your data processing centre for them to enter.

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F AMMTA milking machinetest report form example

(Reproduced with permission from AMMTA)

FACT SHEET

Fact Sheet FMachine test report

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Teat disinfection after milking is one of the most effective cell count and mastitis controlmeasures available. However, it only works if it is done correctly.

Teat disinfectants must be diluted to the correct concentration for use. After mixing, the activeingredients often lose their disinfectant ability with time, and if you include additives toimprove skin condition (emollients) these may reduce disinfectant activity. Any contaminationwith milk and other organic material also reduces activity. Correct mixing each day is best toget maximum performance.

Each time you buy a new stock of teat disinfectant:

nnnnn Read the label on the teat disinfectant container.

o Familiarise yourself with the mixing instructions and anynecessary safety precautions.

nnnnn Calculate the approximate amount of diluted teat disinfectant needed for oneday or, for large herds, one milking.

o If applying the disinfectant in a dip cup, you will need approximately 10 mL ofsolution for each cow in the milking (1 L per 100 cows). For example, you will need1.2 L of disinfectant solution each milking if you are milking 120 cows.

o If applying the disinfectant by spray, you will need approximately 20 mL of solutionfor each cow in the milking (2 L per 100 cows) to achieve complete coverage of theteat. For example, you will need 2.4 L of disinfectant solution each milking if you aremilking 120 cows.

nnnnn Select a clean container which is large enough to hold the volume ofdisinfectant solution you will need for one day or, for large herds, one milking.

o A clear plastic container (such as a large fruit juice container) is ideal so you cansee how much of each ingredient you are adding to the mix.

nnnnn Calculate how much stock disinfectant solution, clean waterand emollient (if required) you will need to make up a day’svolume of disinfectant solution.

o 10 mL of solution for each cow in the milking

o one part iodine disinfectant to three parts water.

G The correct way to mixteat disinfectant

FACT SHEET

Fact Sheet GMixing teat disinfectant

For example, if you are spraying a 120 cow herd:

ððððð solution

20 x 120 x 2 milkings = 2400 mL x 2 = 4800 mL 4800 mL = 4.8 L

You will need 4.8 litres of solution each day.

ððððð disinfectant and clean water

1 part iodine to 3 parts water (1 + 3 = 4)

4.8 divided by 4 = 1.2 litres; 1.2 x 3 = 3.6

You will need 1.2 L iodine and 3.6 L water.

ððððð if you want the solution to contain 10% glycerine

10% of 4.8 L = 480 mL

Glycerine is taken from the water volume.

3.6 L minus 480 mL is 3.12 L

You will need 1.2 L iodine, 3.12 L water, and 480 mL of glycerine.

nnnnn Permanently mark the mixing container for all future mixing. Accuratelymeasure each of the quantities for your solution (use water instead of iodineand glycerine). Mark the container with a permanant marking pen.

nnnnn Measure and mix the solution.

o Accurately measure the volume for each ingredient and add consecutively to theplastic container.

o Clearly mark on the container (with a permanent marker pen) the fluid level andthe name of each ingredient.

Each day as you make up the teat disinfectant required:

nnnnn Use water of very high quality.

o Water from the dairy hot water service is recommended over otherwater sources including town water and rainwater.

o Cool and store the water in a clean container ready for use.

nnnnn Make up the disinfectant solution by adding the disinfectantbase, water and emollient according to the levels marked onthe plastic container.

o Ensure that the correct dilution is made each time.

nnnnn Wash out the plastic mixing container after each use.

n Wash and clean all teat dip cups before each milking.All teat spray containers should be washed and cleanedeach day.

n Tip out all teat disinfectant solution not used at the end of the day.

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With the spotlight focused on cell counts and udder health, do genetics have a part to play inachieving the best results?

Nearly all udder infections are caused by bacteria that enter the quarter through the end of the teat.The likelihood of an infection occurring is a balance between the number and type of bacteriapresent, and the cow’s natural defences designed to stop bacteria entering the teat or multiplying inthe quarter. Although the end of the teat is marvellously set up to reduce entry of bacteria, it stillsometimes occurs.

Most of the factors that affect the balance of infection and defence are influenced very significantlyby the cow’s environment. For example, the number of bacteria present and ‘challenging’ a cowmay be greatly increased if she has sores and cracks on her teat skin, and these may have occurredfor many reasons. Perhaps the laneways are wet and muddy; the teatcup liners may not matchcorrectly to the teatcup shells; the teat spray may have been made up to the wrong concentration.These are factors in the cow’s environment which are influenced by management.

Generally, the greatest impact on udder health is achieved by activities to do with managing cowsbefore, during and after the milking process. However, genetics play a part, too. For example, thecow with the teat sores may have a genetic tendency for poor teat skin health, or she may havelonger than average teats which are more prone to damage.

There is a slight tendency for higher production bulls to leave daughters with higher mastitis levels.Currently selection for production also leads to a small increase in the genetic susceptibility ofcows to mastitis. The level of mastitis inheritance is low (clinical mastitis is about 5% and cellcount level about 15%). Despite this and the fact that genetic changes take many years, improvedudder health from genetics should not be ignored.

How could an improved genetic component to udder health, which reduces the occurrence ofclinical mastitis cases, be achieved?

Logically, it would be sensible to measure the occurrence rate of cases for every progeny testdaughter of each bull. However, because of the low heritability of clinical mastitis, we would needmany more daughters than are currently available for each bull to achieve a reasonable level ofaccuracy.

What about using cell count? Almost all Milk Recorded cows in Australia now have regular cellcounts. This means there is a considerable bank of data which could be used to evaluate bulls. Butdo we know the best way to statistically analyse the data?

H The impact of genetics onmastitis and cell counts

FACT SHEET

Fact Sheet HGenetics

The short answer is ‘no’ – but a number of countries have used different approaches that Australiacould consider. In the United States, a ‘Somatic Cell Score’ is mathematically derived from the cellcounts. In Holland an udder health index has been developed which includes cell count(contributing 50% to the index), udder traits such as attachment and teat length (33%) and greaterthan average milking speed (17%).

One of the problems of the different approaches is that you can’t directly compare one country’smethod with another – like bull proofs!

As it turns out, the simpler methods for doing these calculations may not be too much differentfrom the fancier methods. Various simple techniques have been tested, such as counting theproportion of cell counts for a cow which are above a standard level, and calculating a simpleaverage of the cell counts throughout a cow’s lactation. There are some research groups which areexperimenting with the so called ‘test day model’ which tries to account for the tendency for highercell count cows to be culled during lactation.

The ideal way to evaluate bulls would involve combining both cell count information with anyrecords where cows had been treated for mastitis. The new record design for the Milk Recordingdatabase at Australian Dairy Herd Improvement Scheme (ADHIS) makes it possible for farmers torecord all mastitis events (date, cow identity, quarter, treatments used and culture results ifavailable) in the record for each cow. So this assessment will be possible in the future.

If we did have any of these genetic assessments of bulls, how would we use them? What’s thebottom line?

Now that we are using indexes for selection of bulls, where various factors can be weighted – asoccurs in the Australian Selection Index (ASI) – the inclusion of a factor for udder health makessense too.

But we need to know the extent to which these bull evaluations actually affect profitability on thefarm. Without knowing the dollar differences between bulls due to cell count it is hard to makerational decisions on bulls. For example, Bull A is 20 ASI points higher than Bull B, but Bull A hasa Somatic Cell Score Breeding Value which suggests his daughters may suffer from more udderdisease than normal. Perhaps herds that have low levels of mastitis can ignore the small geneticdifferences between bulls. This might not hold true however, for herds with high Bulk Milk CellCount levels.

When the new Australian Breeding Value (ABV) system has been completed next year, it is verylikely that ADHIS will study udder health scores in an Australian context. We are looking forwardto this step. However, if you currently have a mastitis problem, assessment of the managementfactors in your herd will have a far bigger and faster impact than choice of genetics.

In summary, the gains to be made with respect to mastitis by including a component for udderhealth in indexes for bull selection are likely to be fairly small in the short term, but they will becumulative. These gains will be worthwhile in our efforts to control mastitis, but they will not beour only focus.

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The incidence and severity of mastitis can be affected by a cow’s nutrition. Malnutrition andimbalance of the major dietary nutrients can increase susceptibility to all infections, includingmastitis.

Cows at risk of milk fever (hypocalcaemia), both clinical and subclinical, may have a higherincidence of mastitis cases at calving.

Mammary white blood cell (leucocyte) function, the important defence mechanism againstbacterial infection of the udder, is modulated by antioxidants and other nutrients in the diet.Antioxidants believed to have an effect on the intramammary infection rate include vitamin E(alphatocopherol), vitamin A (beta-carotene), caeruloplasmin (a copper plasma protein) andvitamin C. Copper, zinc and selenium are three micronutrients that are also required forleucocyte antioxidant activity.

Deficiency of these trace elements and vitamins in the diet of dairy cows may predispose theseanimals to increased occurrence and/or severity of mastitis. Supplementation can reduce bothoccurrence and severity of mastitis cases.

There is no evidence that supplementation of dairy cows receiving adequate trace elementsand vitamins has any beneficial effects.

Under normal conditions in Australia, vitamin A and E supplements are not required forpastured cattle. During drought both vitamin A and E supplements are needed if the rationconsists essentially of grain and conserved fodder.

If bloat treatments such as ‘teric’ or oil-based liquids are given to grazing cows, vitamin Esupplementation may be needed.

Suggested nutritional management for mastitis control is:

nnnnn Ensure that dairy cow rations are adequate and balanced in major nutrientsof water, energy, protein and fibre.

nnnnn Use dry cow rations and ‘springer’ or ‘close up’ rations that do notpredispose to milk fever.

I The impact of nutrition onmastitis and cell counts

FACT SHEET

Fact Sheet INutrition

nnnnn If dry cow and heifer rations are deficient in trace elements and antioxidantvitamins, supplement the rations or administer supplements to the cow.

ooooo Ideally supplements should be given by injection at least three weeks before calving,or one month before drying off if given by intraruminal bolus.

nnnnn During drought, supplement with both vitamin A and E if the ration consistsmostly of grain and conserved fodder.

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Many attempts have been made to develop vaccines to increase a cow’s immunity to bacteria

within the udder. This is not an easy task because the action of antibodies and white blood cells in

milk is hard to stimulate by usual vaccination routes – an increase in antibodies in the

bloodstream does not necessarily indicate an enhanced action in the udder.

No vaccination routines for mastitis bacteria are currently recommended in Australia. Despite

this, it is interesting to look at some of the experimental work which has been done over the past

20 years, and the vaccine against coliforms which is used overseas. It is highly unlikely, given

current technology, that a vaccine could be prepared which would protect against all of the wide

range of bacteria that cause mastitis. Rather, vaccines must be targeted against particular bacteria

species. It is also important to emphasise that no vaccination procedures, however successful, are

likely to eliminate the need for good hygiene and milking management on dairy farms.

Staph aureus is very hard to treat with antibiotics and E. coli causes severe clinical cases that

rapidly progress. As a consequence, they have both been studied extensively. Recently a novel

approach to development of a vaccine against Strep uberis has also been explored.

Vaccine research using Staph aureus has found that new infections are not prevented, but severity

of clinical cases can be reduced, and the likelihood that a cow will eliminate the infection (self-

cure) can be increased in vaccinated animals. Australian work in the 1980s led to an experimental

vaccine that helped somatic cells to engulf bacteria that entered the udder. This vaccine was

trialled in an extensive field experiment in Australia, but the results were not significantly

encouraging to proceed with commercial production of the vaccine.

Commercial progress has been made in the United States with a vaccine against coliform mastitis

(using a mutant E. coli called J-5). It is not available in Australia. J-5 is injected subcutaneously

at drying–off, 30 days later and again within 14 days of calving. It stimulates antibodies against a

number of related coliform bacteria. The J-5 vaccine does not eliminate coliform infections in

herds, but combined with good management practices, especially at high risk times in the calving

J The role of vaccination inmastitis control

FACT SHEET

Fact Sheet JVaccination

period, it decreases the number of new infections. One field study with the vaccine showed a

decrease of coliform mastitis from 13% in unvaccinated animals, to 3% in cows that had been

vaccinated.

Recent studies in the UK on the growth and invasion characteristics of Strep uberis have

shown that these bacteria gain some essential nutrients in the udder by activating an enzyme

(plasminogen) in milk. Experimental vaccination has been used to immobilise the activating

molecule and protect the quarters (which were subsequently challenged with Strep uberis

infused into the quarters) from infection by the bacteria. This research is continuing, with

hopes that a commercial vaccine may be available in the future.

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INDEX

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Index

Aabnormal milk

checking for 54–6post-calving 16, 20

acute clinical mastitis 5air admission holes 32air vents 32AMMTA milking machine technician

advice 34, 35, 51, 81testing, servicing and upgrading 79, 81–2

AMMTA milking machine test report 82, 99–101annual mastitis control activities 79antibiotic administration 22antibiotic contamination of milk or meat 2, 23, 24antibiotic selection 21–2antibiotic therapy 1, 20, 22Australian Breeding Values 106Australian Dairy Herd Improvement Scheme 97

Milk Recording database 106Australian Selection Index (ASI) 106average milking time 34

Bbacteria

contagious mastitis 3–4environmental mastitis 4minimising spread between cows 23transmission 3, 37, 50

Bactoscan Counts 6beastings 8black mastitis 5Blanket Dry Cow Treatment 8, 56–7, 66

choice of 93bloat oil 38bloat treatments 107bobby calves 19, 96body cells 6Bulk Milk Cell Counts (BMCC) 7, 20, 27, 80

and drying-off high cell count cows 55culling infected cow effect on 58determining trends 47, 48factory field officer/veterinarian advice 47, 49guidance levels 7herd of origin details, purchased cows 75milk quality payment 10, 58monitoring 44, 47–8

bulls, indexes for selection of 106buying cows 75–6

Dry Cow Treatment history 76udder checks 76

Ccalcium levels 10Californian Mastitis Test (CMT) 12calves

colostrum requirements 95sale of 67, 95

calvingcare with two year old cows and freshly calved cows 17–18clinical cases in freshly calved cows 20–4, 46milk quality check 19reducing exposure to environmental mastitis 15–16

calving environment 15calving pad 15cell counts 6, 50, 88

genetic impact 105–6nutrition impact on 107–8

cells in milk 6–7checking quarters of freshly calved cows 21checking teats as cups come off 32chemical residues 66, 74chlorhexidine disinfectants 38chlorine disinfectants 38chronic mastitis 5chronically infected cows, management 49‘Chux’ towels 28clinical mastitis 5

detection through foremilk stripping 27during lactation 44–6early detection 20freshly calved cows 20–4, 46records to keep 23, 92, 97–8sampling quarters in 87–8

clots on milk filter 45clusters

disinfection 23, 41minimising air leakage when attaching 29use with mastitis cows 23, 41

coliforms 4, 109collecting milk samples for culture 88–90colostrum 8, 17

calf requirements 95colostrum milk 8, 21

withholding from vat 19, 95colostrum mob 8, 96conductivity of milk 9contagious mastitis 3–4, 27, 63

transmission 3, 37, 50Countdown Downunder 1

goals 2records 81

cow associated mastitis 3–4, 27, 37, 50, 63purchased cows 75

cow behaviour 32, 42cow symptoms 5cows, sale of 11, 74cows’ tails, trimming 28

culling 58cows with high cell counts in two consecutive lactations 59cows with three clinical cases in current lactation 59

cup squawks and slips requiring correction 34

Ddaily checks, of machine function 32diet manipulation, drying-off period 64dip cup 39dipping of teats 39, 66dirty teats

fixing areas that contribute to 28, 43, 83washing 28, 43

discard all milk from treated cows 23disinfectants, effectiveness 23, 40disinfection

clusters 23, 41gloves, liners and equipment 40

drug residues 66, 74dry cow mastitis strategy 55–7Dry Cow Treatment 7, 9

administration 64, 65–7avoidance of laneways and yards 64, 67basis of 8choice of Selective or Blanket treatment 56–7, 66, 93cow management 67mark udders of treated cows 67Minimum Dry Period 95, 96not to be used for clinical cases 22not to be used with lactating cows 24paddock requirements 67purchase and storage 57recording details 67, 69usage 56, 66veterinary advice 57withholding periods 12, 19, 57, 67, 95–6

dry cows, weekly check 73dry period

buying cows 75–6observing cows weekly 73selling cows and withholding periods 74

drying-offDry Cow Treatment administration 64, 65–7manipulating diet 64paddock suitability 64

drying-off dates 55, 64drying-off high cell count cows 55drying-off period

Dry Cow Treatment administration 65–7dry-off abruptly to reduce yield to between 5–12 litres per day63–4udder checks 68–9

drying-off the quarter 24

EE. coli 4, 21, 109early lactation, foremilk stripping 27–8effective reserve of vacuum and regulator function, check 34elevated ICCC levels 7emollients 37, 38, 43

emulsified paraffin 38environmental mastitis 4, 63

reducing exposure to at calving 15–16Export Slaughter Interval (ESI) 9

Ffactory field officer advice 51, 81

Bulk Milk Cell Count problems 47, 49filters on pulsator airlines, check 33flag 12, 17–18flaming hair on udders 28foremilk stripping 27–8, 45–6

technique 28when purchasing cows 76

freshly calved cowsfinding and treating clinical cases in 20–4taking time in moving and milking 17

freshly calved heifers, mastitis in 16

Ggenetics, impact on mastitis and cell counts 105–6gloves

disinfection of 40use of 21, 22, 23, 40, 45, 76, 89

glycerine 38good milking technique and consistent routine 15, 18, 27–30

Hhair contamination on udders 28hand-held conductivity meters 9, 46heifer nutrition 18heifers

buying 75cell counts 50

herd cell count problem 88herd improvement 23, 97herd mastitis level

assessment 56Bulk Milk Cell Counts for 47–8

herd testing 80hygiene during milking 40–1hypocalcaemia 10, 107

IIndividual Cow Cell Counts (ICCC) 6, 7, 8, 45, 46

bought cows 75in management decisions 49–50, 56, 80

induced cows 16inflamed udder 5, 11, 20, 21, 45injectable antibiotics 22, 66, 69intermittent milking 63intrammammary treatment 22, 66

correct way to give 91–2

JJ-5 vaccine 109

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LLactating Cow intramammary antibiotic 69lactation period

finding, treating and recording clinical cases 44–6good hygiene during milking 40–1good milking technique and consistent routine 27–30management of teat sores and cracks 42–3monitoring and maintaining milking machine function 31–6post-milking teat disinfection 37–9

late lactation periodculling persistently infected cows 58–9dry cow strategy 55–7

‘let-down’ 11hormone 11, 18, 20, 22

linerscondition check 33disinfection of 40life estimation 36replacement 35–6

Mmachine function 31, 43, 81

daily checks 32milking machine technician assistance 35monthly checks 34–6weekly checks 33

machine stripping, elimination from routine 29‘maintenance only’ diet 64marking systems

for Dry Cow Treatment cows 67for treated cows 22, 92, 97

mastitis 1forms of 5genetic impact 105–6types of 3–4

mastitis controlbenefits 2importance of 5–6nutritional management 107–8vaccination in 109–10

mastitis cows, milking of 23, 41, 49mastitis record sheet 23, 92, 97–8Maximum Residue Limit (MRL) 10, 12meat withholding period 67, 74, 96methylated spirits 57, 89microabscesses 3mild clinical mastitis 5milk aerosol, avoidance of 40milk cultures 11, 20, 21, 76

collecting samples 88–90costs and value 87delivering to vet or lab 90fact sheet 87–90freezing and storage of 46, 87traps 88what are they? 87

milk fever 10, 16, 107milk filter, clots on 45milk let-down 11, 29

hormone 11, 18, 20, 22milk quality check 19

Milk Quality Payment Schemes 10, 58Milk Recording systems 23, 80milk samples for culture 21, 46

collecting samples 88–90purchased cows 76value of 87

milk splashes, avoidance of 40, 45milk symptoms 5, 20milking machine function, checks 31–6, 81milking machine technician

advice 34, 35, 51, 81testing, servicing and upgrading by 79, 81–2

milking machines, testing, servicing and upgrading 79, 81–2milking out 18milking shed routine

good stockmanship in 27training heifers in 17

milking time guide 34mixing teat disinfectant 38, 66, 103–4monitoring

Bulk Milk Cell Counts 44, 47–8milking machine function 31–6

monthly checks, of machine function 34–6muddy udders, fixing areas that contribute to 28, 43, 83

NNational Vendor Declaration Form 9, 11non-antibiotic intramammary products 57nutrition

drying-off 64heifers 18impact on mastitis and cell counts 107–8

Oovermilking, avoidance of 18, 30Oxytocin 11, 18, 20, 22

late pregnant cows 69

Ppost-calving check 16post-milking teat disinfection 37–9premilking preparation of udders 16professional advice 24, 34, 35, 43, 47, 49, 51, 81Pseudomonas 4, 38, 63pulsators, listen to 32

RRapid Mastitis Test (RMT) 12, 46recording details of clinical cases 23, 92, 97–8regulators, listen to 33replacement heifers 19review and planning period

annual mastitis control activities 79Countdown Downunder records 81fix areas that make udders muddy 83milk recording (herd testing) 80milking machines testing and servicing 81–2teat disinfectants review 82–3teat spray units servicing 82

Sscar tissue 3Selective Dry Cow Treatment 8, 56–7, 66, 80

choice of 93selling calves, withholding periods 67, 95selling cows 11

withholding periods 74severe clinical mastitis 5singeing hair on udders 28‘skip-a-day’ milking 63Somatic Cell Count (SCC) 6Somatic Cell Score 106somatic cells 6spraying of teat disinfectant 39Staph aureus 3, 5, 7, 27, 87, 88, 109

transmission 3, 37, 50sterile bottles (for milk samples) 89, 90Strep agalactiae 3, 5, 7, 46, 49, 76, 87

cell counts 6penicillin sensitivity 4, 88transmission 3

Strep uberis 4, 87, 109, 110stress, and ICCC levels 7stripping out 20, 22, 24

clinical quarters, drying-off cows 69subclinical mastitis 5, 7, 9

detection 12suspect cows, checking 45–6swollen quarters

checking 21, 45, 68, 73dry cows 73drying-off cows 68

Tteat canal 63

inserting antibiotic tube into 92teat disinfectants 37

addition of emollients 37, 38, 43, 103daily mixing 38, 66, 103–4dilution 38highest quality water for mixing 38review 82–3

teat disinfection 37–9following Dry Cow Treatment 66operator technique 39prior to collecting milk samples 88prior to intramammary treatment 92spray or dip whole surface 39spray pattern 39

teat end damage 43teat ointments 43‘Teat Seal’ 57teat sealing 63, 67, 68teat skin condition 38, 42–3teat sores and cracks 42–3teat sphincters 43teat spray units

servicing 82spray patterns 39

teatcup linerscondition check 33‘cow milkings’ life estimation 36disinfection of 40replacement 35–6

teatcupsair leakage through 56placement on clean, dry teats 28, 43placement when teats become plump with milk 29removal method 30

teats, check as cups come off 32‘three teaters’ 59, 66Total Plate Counts 6, 10trace element deficiency 107training heifers in milking area before calving 17trimming cow’s tails 28twisted liners, check for 33two year old cows

severe udder oedema 17–18taking time in moving and milking 17

Uudder checks

drying-off cows 68–9when purchasing cows 76

udder health index 106udder oedema 12

in fresh cows 17–18udder symptoms 5undermilking 34

avoidance of 18, 30drying-off 64

Vvaccination in mastitis control 109–10vacuum gauge readings 32veterinary advice 51, 81

Bulk Milk Cell Count problems 47, 49Dry Cow Treatment 57swollen quarters, drying-off cows 69teat sores and cracks 43where quarter fails to respond to treatment 24

vitamin deficiency 107

Wwashing dirty teats 28, 43watch milk entering the receival can 32weekly checks, of machine function 33wet teats, dry before placing teatcups 28, 43white blood cells 5, 108white oil 38withholding periods 12, 23, 24

Dry Cow Treatment 12, 19, 57, 67, 95–6selling calves 67, 95selling cows 74

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Acknowledgements

Members of the Australian Mastitis Advisory Council since 1996. The asterisks denote

people who participated in developing these guidelines:Jeff Andrews Department of Primary Industries, Qld

Pauline Brightling* DRDC

John Bone Capple Vale, Vic

John Bywater* Dairy Farmers Group, Qld

Harry Collins* Pharmacia Upjohn, NSW

John Craven DRDC

Bill Darmody* Moe Veterinary Clinic, Moe, Vic

Tom Davison DRDC

Lee Fitzgerald* Milkerware, Tatura, Vic

John Furphy* Murray Goulburn Co-operative Co. Ltd, Vic

Richard Habgood Department of Natural Resources and Environment, Vic

Terry Hehir (Chair)* Kyabram, Vic

Ian Hubble* Department of Primary Industries, Water and Environment, Tas

Angus Hume* Australian Milk Harvesting Program

Peter Maguire Westfalia Landtechnik, Vic

Jakob Malmo* Maffra Veterinary Centre, Vic

Jill McKenzie Mt Compass, SA

Graeme Mein* University of Wisconsin, United States

John Oldaker Mawbanna, Tas

Kem Perkins* Latrobe, Tas

Robert Poole Australian Dairy Herd Improvement Scheme

Sally Reid DRDC

Graeme Rogers* Bonlac Foods Ltd, Vic

Diane Ryan* NSW Agriculture, NSW

Invaluable help was also offered by many farmers and professional service providers with

an interest in milk quality throughout Australia. Written contributions were receivedfrom:Pierre Baychelier Pfizer Pty Ltd, NSW

Glen Beath Willunga Veterinary Services, Willunga, SA

Greg Cavanagh Gympie and District Vet Services, Gympie, Qld

David Chaffey Kiama Veterinary Hospital, Kiama, NSW

Russell Coote Victorian Dairy Industry Authority, Vic

Gabriel Hakim Dairy Equipment Specialists, Warragul, Vic

Stuart Halliday University of Queensland, Dayboro, Qld

Graham Hancock Buffalo, Vic

Sue Hides Department of Natural Resources and Environment, Maffra, Vic

Ian Holmes Department of Natural Resources and Environment, Echuca, Vic

Meaghan Johnston Milking Research Centre, Ellinbank, Vic

Sandy McClintock Genetics Australia Co-op, Bacchus Marsh, Vic

Mal Maroske Department of Primary Industries, Oakey, Qld

George Miller Department of Natural Resources and Environment, Benalla, Vic

Bill Morgan Timboon Veterinary Group, Timboon, Vic

John Ryan ProV Dairy Systems, Beaudesert, Qld

Richard Shephard Herd Improvement Co-op, Maffra, Vic

Greg Stevens Primary Industries SA, Flaxley, SA

Jos Vermunt Maffra Veterinary Centre, Maffra, Vic

Peter Wendell-Smith Smithton Veterinary Service, Smithton, Tas

Jack Winterbottom Maffra Veterinary Centre, Maffra, Vic

Peter Younis Timboon Veterinary Group, Timboon, Vic.

Farm Guidelines for Mastitis Control

Documents

Transcript of Farm Guidelines for Mastitis Control