CHICKS

AGAB, H., ABBAS, B. & MOHAMED, A.S. 2008. Causes of mortality among ostriches (Struthio camelus) and emus (Dromaius novaehollandiae) raised commercially in Saudi Arabia. Assiut Veterinary Medical Journal, 54: 244-260. The incidence and causes of mortality in a mixed ratite farm which produced ostriches and emus were recorded over 4 production seasons (1998-2001). The mean annual mortality rates for ostrich and emu chicks during the rearing phase were 29.1 and 21.6%, respectively. The mortality rate was 46.3% for the whole chick population during 4 production seasons. Notable causes of chick mortality were leg deformity, fading chick syndrome, Newcastle disease (NCD), suffocation and enteric infection. The crude mortality rate for ostrich and emu growers throughout the study period was 18.7% with an annual mean of 12.3%. Sand impaction, NCD and leg deformity were the main causes of mortality among this group of birds. Septicaemic pasteurellosis was the major cause of death among breeding ostriches, whereas wound infection and peritonitis assumed minor roles. Egg peritonitis, accidents and enteritis were the most important causes of death among emu breeders.

AKINCI, Z. & BAYRAM, I. 2002. Growth and survival rate of ostrich chicks in Usak province. Ankara Universitesi Veteriner Fakulltesi Dergisi, 49 (2): 143-150.

This study was conducted in order to investigate the growth, survival rate and phenotypic correlations between the body weight and some body measurements from 3 to 12 weeks of age of ostrich chicks (Struthio camelus) which were brought to a farm in Usak province (Turkey) from Belgium at 16 days of age. A total of 73 ostrich chicks aged 17 days were used in this study. Two diets were used throughout the experiment: firstly, a prestarter diet containing 20.00% crude protein and 2.850 kcal/kg of ME from 17 to 58 days of age, secondly, a starter diet containing 18.00% crude protein and 2.800 kcal/kg ME from 59 days to the end of the study (90 days of age). Individual body weights and circumference of chest, the length, circumference and thickness of metatarsus were recorded weekly from 3 to 12 weeks of age. The growth curves of birds were evaluated by the Gompertz equation. Mean body weights, the amount of concentrate feed consumed per 1 kg weight gain and survival ratios were found to be 3440, 7550, 10820 g. 1.11, 2.4, 5.07 and 90.41, 89.04 and 84.93% at 4, 8 and 12 weeks of age, respectively. In this study, maximum weight gain was observed at 6 and 7 weeks of age and mortality related to leg and toe disturbance was recorded as 5.63 per cent. All positive and significant (P<0.001) phenotypic correlation estimated between body weight and body measurements. As a result, it was concluded that Usak province could be suitable for growth of chicks aged 0-3 months.

ALVARENGA, A.B.B. & BOERE, V. 2008. The size of the egg does not predict the physical development of ostriches (struthio camelus) at fifteen days old. Ciencia Rural, 38: 802-806. The size of the eggs is related to survival and chick growth in precocial birds. The interrelationship between egg and chick development can be important for the animal production, supplying data for strategic decisions of economy, handling and animal welfare. This study analyzed the relation between the weight of the eggs and the development of ostrich chicks (N=48) at age of fifteen days old. The chicks were kept in indoor nurseries, in groups, without parental care, and fed commercial feed. It was recorded the weight, the back height and the length of the tarsus-metatarsus. There was a significant difference in the weight of the eggs, but the correspondent body chicken measures were not statistically different. In agreement to the studies in other species of birds, the weight of the egg does not seem to influence the growth of the ostriches at fifteen days old.

ASLAN, L., GENCCELEP, M., KARASU, A., DUZ, E., ALKAN, I. & BAKİR, B. 2009. Extremity problems in ostrich chicks and their treatment. Journal of Animal and Veterinary Advances, 8: 903-906. Extremity problems in 120 ostrich chicks were investigated in this study. Fledglings were followed for 1 year and extremity problems were evaluated as congenital or acquired. In the study, congenital lower extremity problems were found in 17.5% of the cases (both

extremities extended sideways in 10 cases, 1 extremity extended sideways in 3 cases, one leg extended forward and the other back in 4 cases, big toe retrovert in 2 cases, 5th toe deviated towards underneath of the big toe, totaling to 21 cases) and acquired lower extremity problems in 19.64% of the cases (tibiotarsal luxation in 6 cases, tarsal bone fracture in 1 case, fractures in radius-ulna in 1 case, injuries of the extremities in 9 cases and arthritis in the tarsal joint in 2 cases and in proximal interphalangeal joint in 3 cases, totaling to 22 cases). Extremity problems were found in 43 (35.83%) ostrich chicks out of 120 (congenital in 21 cases and acquired in 22). Of these 43 cases, it was observed that 29 (67.44%) were healed with the treatment applied, whereas, 14 (32.56%) did not heal. It was concluded in the study that the extremity problems causing great economic losses in ostrich husbandry can be minimized with prevention, early diagnosis and proper treatment.

ASLAN, L., KARASU, A., OZKAN, C., DUZ, E., KAYA, A. & AKGUL, Y. 2009. Medical and surgical treatment of gastric impaction in juvenile ostriches. Journal of Animal and Veterinary Advances, 8: 1141-1144. Radiological diagnosis and medical and surgical treatment options of the constipation problem seen in ostrich chicks were investigated in this study. The study was performed in a farm that 60 ostrich chicks were kept that are between 8 and 12 weeks of age. Our clinic was applied to upon seeing loss of appetite, weight loss and sudden death in 2 animals in the farm. Fifteen sick ostrich chicks that gastric impaction problem was found with clinical and radiological examination were included in the study. In the ostrich chicks that were found to be sick in clinical examination, clinical symptoms were observed like loss of appetite, weakness, dehydration, reduced number of defecations, drooping wings, messiness of feathers and inability to stand. Medical treatment was applied to 7 animals that general health status was not severe and that obstruction was found to be not complete in radiological examination and proventriculotomy operation was performed in 8 animals that stomachs were found to be full with foreign materials in radiological examinations and with serious health condition and also in 2 ostrich chicks that did not respond to medical treatment. Five patients out of 7 that medical treatment was applied and 8 patients out of 10 that were treated surgically responded to the treatment and got well. In the autopsies of the animals that did not respond to the treatment and died, macroscopic edema, erosion and hemorrhagic ulcers were found in proventriculus and ventriculus mucosa and in addition, stomach was filled with stones, sand, pieces of wood, metal and glass, rough feed particles and clover fibers. It was concluded that radiological examination will determine the level of obstruction, make the treatment easier and will direct it. It was also, concluded that emergency surgical treatment in cases with complete obstruction not responding to medical treatment would be beneficial if performed with no time loss.

BAYRAM, I. & AKINCI, Z. 2003. Effect of hazelnut meal added to the ostrich rations on growth. Indian Veterinary Journal, 80: 1022-1025. Effects of 10 and 20% hazelnut meal substitutions in place of soyabean meal was studied in ostrich chicks (Turkey). The experimental period was 8 weeks. There were no significant differences among the groups in bodyweight gain and feed conversion ratio. Hazelnut meal addition decreased the feed consumption (P<0.001).

BLUE-MCLENDON, A. & HOMCO, L.D. 1995. Ultrasound determination of yolk sac size in ostrich chicks. Association of Avian Veterinarians Main Conference Proceedings, 1995: 311-312.

BOCKHEIM, G. 2002. Raising ostrich chicks at Potawatomi Zoo. Avicultural Magazine, 108: 127-135.

BONATO, M., EVANS, M.R. & CHERRY, M.I. 2009. Investment in eggs is influenced by male coloration in the ostrich, Struthio camelus. Animal Behaviour, 77: 1027-1032. Life history theory predicts that females should modify their investment in a particular breeding attempt according to the likelihood of its success, as the investment of females in reproduction is typically higher than that of males. The ostrich mating system is promiscuous,

and is thus a particularly interesting one in which to investigate differential investment by the sexes. To date, there has been no evidence that female ostriches discriminate between males as potential mates, but the degree of dimorphism in this promiscuous species and the variation in chick size within clutches suggest that differential maternal investment is likely. We investigated the relationship between egg mass and coloration of the feathers, bill, neck and legs of 15 male ostriches, maintained in a breeding flock at an ostrich farm in South Africa. Paternity was determined using microsatellite markers. We found that the colour of the neck, white and black body feathers, and the brightness of black feathers, predicted egg mass. These traits are exposed during the male courtship display, so we suggest that these visual cues influence the degree of maternal investment in eggs through their influence on female perception of mate quality.

BONATO, M., EVANS, M.R., HASSELQUIST, D., CLOETE, S.W.P. & CHERRY, M.I. 2009. Growth rate and hatching date in ostrich chicks reflect humoral but not cell-mediated immune function. Behavioral Ecology and Sociobiology, 64: 183-191. A tradeoff between immune response and life history traits, in particular growth rate, has been documented in various bird species. Ostriches are fast-growing birds and a typical feature of cohorts is that offspring often differ greatly in size. We investigated the relationship between hatching date and growth rate of chicks and both cell-mediated (measured using a phytohaemagglutinin (PHA) injection) and humoral immune responses in ostrich chicks maintained on a research farm. Chicks with higher growth rates had intermediate responses to both diphtheria and tetanus toxoids. By contrast, no relation between growth rates and responses to PHA injection were found. We conclude that chick growth rate variation may be explained beyond a certain threshold by a tradeoff between the humoral response and growth. Both responses to PHA injection and humoral responses in chicks were found to decrease with chick hatching date. Within the context of ostrich farming, these results could partially explain size variations observed in cohorts of chicks, as well as high mortality rates during their first 3 months of age.

BOUDA, J., NUNEZ-OCHOA, L., ÃVILA-GONZÃLEZ, E., DOUBEK, J., FUENTE-MARTINEZ, B. & AGUILAR-BOBADILLA, J. 2009. Blood acid-base and plasma electrolyte values in healthy ostriches: the effect of age and sex. Research in Veterinary Science, 87 (1): 26-28.

The effect of age and sex on blood acid-base and plasma electrolyte values was determined in venous blood samples from 45 clinically healthy ostriches (Struthio camelus) from 26 days to 6 years of age. Animals were divided by age into four groups and the group of adults was divided by sex into two subgroups. Blood samples were collected without sedation. There was a significant (P<0.05) age difference in blood values of base excess (BE), plasma HCO3-, total CO2 (TCO2), Na+, K+, Cl- and anion gap (AG). The highest plasma concentrations of Na+, Cl- and value of AG were found in adult ostriches with a steady decrease to chicks. A significant (P<0.05) sex difference in adult animals with higher blood pH, lower blood values of pCO2, BE, plasma concentrations of HCO3-, TCO2 and K+ was found in females. We concluded that blood acid-base values and plasma electrolyte concentrations in ostriches are affected by age and sex. BRAND, M.M., CLOETE, S.W.P., HOFFMAN, L.C. & MULLER, M. 2005. A comparison of live weights, body measurements and reproductive traits in Zimbabwean Blue ostriches (Struthio camelus australis) and South African Black ostriches (S. camelus var. domesticus). World Poultry Science Association (WPSA), Beekbergen, Netherlands, Proceedings of the 3rd International Ratite Science Symposium of the World's Poultry Science Association (WPSA) and 12th World Ostrich Congress, Madrid, Spain, 14th-16th October, 2005 : 73-80.

Data obtained from a pair-mated ostrich flock located at Oudtshoorn in South Africa were used to estimate possible line differences for live weight, body measurements and reproductive traits in sexually mature ostriches of the Zimbabwean Blue (ZB) and South African Black

(SAB) strains. At the commencement of breeding ZB males were heavier (P0.50) by any of the independent variables considered. The percentage of shell deaths was affected (P0.50) by any of the independent variables considered. The percentage of shell deaths was affected (P0.50) by any of the independent variables considered. The percentage of shell deaths was affected (P0.10). Overall, SAB females produced 84% more chicks than their ZB contemporaries in a season (27.0±1.7 vs. 14.7±2.1 chicks respectively; P<0.01). Further studies are needed to determine the applicability of a structured crossbreeding programme for improving production in the commercial ostrich industry.

BRAND, T., BRAND, Z., AUCAMP, B. & KRUGER, A. 2003. Energy and protein for growth and breeding. Feed Mix, 11: 11-13. Experiments were conducted at the Ostrich Research Unit of the Elseburg Agricultural Research Centre in South Africa to quantify the nutrient requirements of ostriches and to determine the nutritive value and optimum inclusion levels of various ingredients. These were done to optimize feeding standards in an attempt to reduce input costs for the ostrich industry. To determine protein and energy requirements for growers, nine diets with three different protein and amino acid levels as well as three different energy levels were fed ad libitum to slaughter birds (4-11 months of age, 25-89 kg body weight). Eighteen groups of ostriches consisting of 5 individuals per group were formed. Ostriches on low energy diets were observed to feed more frequently than ostriches on high energy diets, with a resultant lower feed conversion ratio. The skin surface of ostriches on high energy diets was ~3% greater than that of birds on low energy diets. Protein content had a significant effect on growth rate between 4-5 months of age (between 25.0-34.5 kg); however, this difference was not observed during the weighing interval at 4-6 months. A higher protein content led to a lower percentage of grade 1 skins, or more skin damage. In a follow up study to further examine the effect of protein content on skin grade, two isoenergetic diets were used either with high or low protein levels. The birds were fed ad libitum from 4-9 months of age (41-91 kg body weight). It was confirmed that skins of birds fed high protein diets obtained a lower grading value due to significantly more kick marks. Skin surface and other leather characteristics did not differ in birds receiving a diet with 13 or 16% crude protein with attended amino acid profiles. For breeders, energy and protein requirements were determined using 9 different breeding ostrich diets with three energy and protein levels, with corresponding levels of lysine. The diets were fed to 90 breeding pairs during the breeding season from June to January. Higher energy levels tended to produce heavier females by the end of the breeding season. Females consuming the low energy diet, that had lost mass during the breeding period, regained their mass within the first three months of the normal rest period from February to May. In a follow up study using 90 breeding pairs, both protein and energy levels were lowered in order to determine the level at which production starts to be negatively affected by these nutrients. Energy levels below 8.5 MJ ME/kg DM had negative effects on production, lowering the body weights of female birds by ~24 kg over the breeding season as well as decreasing egg production by 28% and the number of chicks produced per female by 23%. The combined results indicate that the current nutrient levels of ostrich diets may potentially be lowered under certain circumstances. However, the lack of sufficient scientific information regarding the nutrient requirements of ostriches as well as the nutritive value of raw materials for these animals currently limit such decisions.

BRAND, Z., CLOETE, S.W.P., MALECKI, I.A. & BROWN, C.R. 2008. Genetic relationships between water loss and shell deaths in ostrich eggs, assessed as traits of the female. Australian Journal of Experimental Agriculture, 48 (10): 1326-1331.

The ostrich industry suffers from a high rate of embryonic mortality during artificial incubation of eggs. Data from 34 285 eggs were used to derive 969 female-year records for evaporative water loss (WL), treated as a trait of the female. Heritability was significant for WL at a level of 0.40-0.41 (both after 21 and 35 days of incubation). WL at 21 and 35 days was negatively correlated on the genetic level with chick weight at hatching (-0.84 and -0.81, respectively). Shell deaths did not exhibit high levels of genetic variation (0.06), but were affected by the permanent environment of the female (0.33). Shell deaths were correlated with WL on a genetic level (-0.34 to -0.41), but the estimated genetic correlations were associated with

high standard errors and are, therefore, not very robust. Further research is needed to obtain more accurate genetic relationships between traits influencing incubation.

CARVALHO, S.F.M., FRENEAU, G.E. & SANTOS, A.L.Q. 2006. Methods for semen collecting in ostrich (Struthio camelus Linnaeus, 1758) and emu (Dromaius novaehollandiae Linnaeus, 1758), and some quantitative and qualitative characteristics. Bioscience Journal, 22: 159-168. Due to the importance of the ostrich S. camelusand emu D. novaehollandiae eggs in the agribusiness sector in Brazil as it is being imported for a high price specially for the fertile eggs, chicks and adults it is a must to maintain and continuously improved on the reproductive management of the ostrich hens. Thus a review on the reproductive diseases, reproductive behaviour, management and treatment of the disease is discussed. Emphasis of the study also focused on the methods for collecting semen and subjecting it to qualitative and quantitative analysis.

CHRISTENSEN, J.W. & NIELSEN, B.L. 2004. Environmental enrichment for ostrich, Struthio camelus, chicks. Animal Welfare, 13: 119-124. Commercially reared ostrich chicks are typically kept in barren, indoor environments. This experiment investigated the effects of environmental enrichment on the pecking behaviour, exploration, food consumption and novelty responses of ostrich chicks aged 10 to 21 days. Four groups of 20 randomly selected ostrich chicks were housed in heated huts at one day of age (Day 1), and at Day 10 were allowed access to sand-covered areas (30 m2) that were either barren (control: n=2 groups) or enriched with cabbage, coniferous cones and sticks (enriched: n=2 groups). Pecking behaviour was recorded by focal sampling the behaviour of five chicks per group for four 5 min periods per day on Day 10 and Day 13. All enriched chicks pecked at the cabbage, of which they consumed considerable amounts (26±3 g/chick/day). The enriched chicks did not have higher overall pecking frequencies but tended to peck less at fixtures in the pen, compared to control chicks. Additionally, the enriched chicks showed increased exploration in terms of the percentage of chicks observed outside the heated huts. In a novel object test, enriched chicks stayed closer to and delivered more pecks at sorrel (Rumex acetosa) than did control chicks, whereas there was no difference between the treatment groups in their response to adult ostrich feathers. Enriched chicks consumed more food (79±0.4 g/chick/day) than did control chicks (67±0.9 g/chick/day) during the experimental period. We suggest that environmental enrichment improves the welfare of ostrich chicks in terms of increasing exploration and reducing pecking at fixtures in the pen, without compromising food consumption.

CILLIERS, F. 2004. Husbandry and nutritional practices in chick rearing. Veterinarski Fakultet Sveučilišta u Zagrebu (Faculty of Veterinary Medicine, University of Zagreb), Zagreb, Croatia, Proceedings of the 11th Ostrich World Congress, Island Great Brijun, Croatia, 15-17 October 2004, : 121-129.

Chick rearing is defined as the growth phase from one-day-old to 4 months of age. Numerous factors could influence chick quality like the genetic quality of breeders and the incubation procedures, but the most important factor is the nutritional status of the breeders. Majority of nutrition related disorders experienced during the first three weeks of life could be associated with nutritional deficiencies of breeders. Chick rearing is by far the most challenging phase in ostrich production. Although it is high risk, this stage has the highest potential for maximum return per unit input.

CLOETE, S.W.P., BRAND, M.M., HOFFMAN, L.C. & MULLER, M. 2008. Live weight and reproduction performance of Zimbabwean Blue and South African Black ostriches. South African Journal of Animal Science, 38: 65-73. Data obtained from a pair-mated ostrich flock located at Oudtshoorn in South Africa were used to derive line differences for liveweight and reproductive performance in sexually mature ostriches of the Zimbabwean Blue (ZB) and South African Black (SAB) strains during 2003 to 2006. At the commencement of breeding, ZB breeding stock averaged between 9 and 13%

heavier than SAB. At the cessation of breeding, the superiority of ZB birds was reduced to between 4 and 8%, expressed relative to SAB breeding stock. Liveweight at the commencement of breeding was complicated by an interaction between sire line and year. The interaction resulted from no line differences between SAB and ZB males in 2003, contrasted to marked differences in subsequent years. Egg production was affected by dam line, but not by the line of the sire or the interaction between dam line and sire line. Egg production of SAB females was almost twice that of ZB, at 43.3 and 23.3 eggs per season, respectively. The number of infertile eggs was not affected by any of the independent variables considered. The number of shell deaths was affected by both sire line and dam line. Overall, SAB females sustained lower levels of shell deaths than ZB females, while the eggs produced by mates of SAB males had higher shell deaths than mates of ZB males. Chick production was affected by dam line; the effects of sire line and the dam line × sire line interaction being non-significant. Overall, SAB females produced more than double the number of chicks produced by their ZB contemporaries, at 23.1 and 10.6 chicks per season, respectively. Both egg production and chick production were affected by a dam line × year interaction. No dam line difference was observed during 2003, whereas SAB females clearly outperformed ZB females in subsequent years. Further studies on ostrich bloodlines and their crosses are needed to devise a selection and crossbreeding strategy for improving production and profitability in the industry.

CLOETE, S.W.P., BRAND, Z., BUNTER, K.L. & MALECKI, I.A. 2008. Direct responses in breeding values to selection of ostriches for liveweight and reproduction. Australian Journal of Experimental Agriculture, 48: 1314-1319. Estimates of genetic parameters and genetic trends for reproductive traits and for liveweight at the commencement of breeding were obtained using data from a pair-mated ostrich flock located at Oudtshoorn in South Africa. Heritability estimates were 0.17-0.18 for egg production, 0.15-0.17 for chick production and 0.35-0.37 for liveweight. Female permanent environmental effects amounted to 0.11-0.17 for egg production, 0.14-0.19 for chick production and 0.30-0.31 for liveweight. Service sire exerted significant effects only on egg production (0.03-0.08) and chick production (0.05-0.10). Genetic correlations of reproductive traits with liveweight were not different from zero. Initial selection in the flock was based on reproduction, in the sense that replacements were descended from the females with the highest uncorrected number of chicks produced during their season of hatch (Chick Production line). Animals that were hatched during the period from 1996 to 2006 were used to establish two more populations. The heaviest birds at ~16 months of age were used as replacements in the line selected for liveweight (Liveweight line). Birds selected for the Control line were of average uncorrected liveweight at ~16 months, and were descended from females that produced an average number of chicks in their season of hatch. Overall, the Liveweight line had higher breeding values than the Control line for the period from 1996 to 2006. The response seemed to be associated with screening from the larger population on breeding values for liveweight, as no cumulative genetic gains were evident since 1996. Breeding values for chick production in the Chick Production line were increased by 3.1% per year from 1990 to 2006. Regressions of individual breeding values in the Control line on the year of hatch indicated no genetic change in either liveweight or chick production. Genetic change in particularly reproduction thus seems feasible in commercial ostriches.

CLOETE, S.W.P., BUNTER, K.L. & BRAND, Z. 2005. Phenotypic performance of ostrich females selected for live weight or chick production relative to an unselected control line. World Poultry Science Association (WPSA), Beekbergen, Netherlands, Proceedings of the 3rd International Ratite Science Symposium of the World's Poultry Science Association (WPSA) and 12th World Ostrich Congress, Madrid, Spain, 14th-16th October, 2005, : 99-104.

Phenotypic selection of animals hatched during the period from 1996 to 2000 was used to establish three selected populations in a pair-bred ostrich flock in the Klein Karoo region of South Africa. The heaviest birds at approximately 16 months of age were used as replacements in the line selected for live weight (Live Weight line). Replacements in the line

selected for chick production (Chick Production line) were descended from the females with the highest uncorrected number of chicks produced during their season of hatch. Birds selected for the Control line were of average uncorrected live weight at 16 months, and were descended from females that produced an average number of chicks in their season of hatch. Phenotypic performance levels in these lines were assessed, using 351 to 380 hen-year records obtained during the period from 1998 to 2003 from females with at least two records in the data set. The data were analysed by least squares procedures, the model including the random effect of animal to account for repeated records yielded by the same individual. Data analysed included live weight at the commencement of breeding, total number of eggs produced, total number of chicks produced and hatchability (calculated as chick production divided by total number of eggs produced for females producing >3 eggs during a mating season, expressed as a percentage). The number of days in the breeding season was used as a linear covariate for egg and chick production to account for differences in the length of the breeding season. Repeatability estimates (±s.e.) derived from the analyses were 0.52±0.05 for live weight, 0.29±0.06 for egg production, 0.35±0.06 for chick production and 0.44±0.06 for hatchability. Egg production increased (P<0.01) by 0.071±0.023 eggs per day increase in the length of the breeding season. The corresponding increase in chick production amounted to 0.033±0.016 (P<0.05). The average (±s.e.) live weight at the commencement of breeding were 111±2 for the Control line, 122±2 for the Live Weight line and 114±2 for the Chick Production line. Females in the Live Weight line were thus approximately 10% heavier (P<0.01) than Control line individuals. Means for number of eggs produced per female per season were 36.6±3.0 for the Control line, 31.5±3.0 for the Live Weight line and 43.7±3.0 for the Chick Production line. Corresponding means for chick production were respectively 16.4±2.4, 16.4±2.4 and 24.2±2.4, demonstrating a 48% advantage in the Chick Production line compared to the other lines (P<0.05). Corresponding means for hatchability were 39.1±3.8, 48.8±3.8 and 49.9±3.8, with the advantage of the selection lines relative to the Control line being significant (P<0.05). Selection line differences were consistent with the selection pressure applied, in the current flock for live weight, and in the next generation for chick production.

CLOETE, S.W.P., BUNTER, K.L., LAMBRECHTS, H., BRAND, Z., SWART, D. & GREYLING, J.P.C. 2006. Variance components for live weight, body measurements and reproductive traits of pair-mated ostrich females. British Poultry Science, 47: 147-158. Estimates of genetic parameters for reproductive traits, live weight and body measurements were obtained using data from a pair-mated ostrich flock at Oudtshoorn in South Africa. Reproductive traits included total egg and chick production, along with hatchability percentage. Live weight, chest circumference and tail circumferences were recorded at the commencement and cessation of breeding. Heritability estimates (h2) were 0.23 for egg production, 0.20 for chick production, 0.10 for hatchability, 0.20 to 0.34 for live weight, 0.12 for chest circumference and 0.30 to 0.38 for tail circumference. Female permanent environmental effects (c2) amounted to 0.18 for egg production, 0.18 for chick production, 0.21 for hatchability, 0.32 to 0.36 for live weight and 0.23 to 0.32 for chest circumference. Service sire exerted significant effects only on hatchability (0.22) and subsequently chick production (0.09). Genetic correlations of reproductive traits with live weight were low to moderate, variable in sign, and did not differ significantly from zero. Correlations between live weight recorded at the beginning and end of the breeding season were unity for additive genetic and permanent environmental effects. Egg and chick production were highly correlated genetically and phenotypically, with the genetic correlation exceeding the theoretical limit. In unconstrained analyses, hatchability was positively related to chick production, including at the service sire level. Selection gains in the current flock and future generations are likely. No significant adverse relationships were found between live weight, body measurements and reproductive traits.

CLOETE, S.W.P., ENGELBRECHT, A., OLIVIER, J.J. & BUNTER, K.L. 2008. Deriving a preliminary breeding objective for commercial ostriches: an overview. Australian Journal of Experimental Agriculture, 48: 1247-1256. Ostrich farmers rely on skins and meat as their most important sources of revenue, with feathers being of secondary importance. This paper provides a summary of parameter

estimates (heritabilities and genetic correlations) estimated from the resource flock held at the Oudtshoorn Research Farm. Traits considered were egg production, chick production, mature liveweight, offspring slaughter weight and skin traits. Feather weight of mature breeding birds was not included, as revenue received for this commodity is comparatively low, and mostly reliant on quality. All the traits considered were moderately to highly heritable, and reproduction traits in particular were highly variable. No substantial unfavourable genetic correlations were noted, and worthwhile gains in all traits appear to be achievable within a selection objective based on economic principles. Economic weights for key traits were obtained from a bio-economical input-output simulation model that was prepared for the industry. A simple preliminary selection index including chick production (as a hen reproductive trait) and slaughter weight (as a measure of growth) appears to be adequate for the present needs, given the limited availability of routinely recorded traits. A key performance trait that is currently missing from the economic assessment is chick survival, which is known to be low and highly variable among ostrich flocks. Further information will be added as it becomes available.

CLOETE, S.W.P., LAMBRECHTS, H., PUNT, K. & BRAND, Z. 2001. Factors related to high levels of ostrich chick mortality from hatching to 90 days of age in an intensive rearing system. Journal of the South African Veterinary Association, 72: 197-202. Ostrich chick mortality was studied in 2522 chicks that were hatched artificially during the 1999/2000 breeding season. High levels of mortality were observed, with 1978 (78.4%) of these chicks dying before 90 days after hatching. A total of 46.7% (1177) of these chicks died before 28 days of age, and a further 30.7% (801) died between 28 and 90 days post-hatching. Chick mortality to 28 days of age could not be conclusively related to sex, day of external pipping or breeder diet. Mortality rates were higher (P18%) was recorded were also at risk of succumbing before 28 days of age. Chick mortality percentages for the period from 28 to 90 days of age exceeded 80% in chicks weighing an average of 1050 g at 28 days. Mortality percentages declined sharply at higher live masses, to between 20 and 30% in chicks weighing ≥1950 g. This 'core' level of mortality remained throughout, even in the heaviest chicks. It was concluded that the high levels of chick mortality could be related to stress in chicks, resulting from an inability to adapt to the rearing environment. The high subsequent mortality percentages of low live mass chicks that survived to 28 days after hatching could probably be attributed to residual setbacks suffered earlier. A better understanding of the underlying principles involved in ostrich chick mortality in intensive rearing environments is required for progress in this field, resulting in more predictable survival rates under these conditions.

COETSEE, J. 2000. Regte rantsoene verseker geil kuikenoes. Landbouweekblad, 25: 34-36. Discusses the correct choice of breeding ratios for ostriches according to the farming environment and good management practices to ensure success with ostrich breeding. An expert, Dr Fanus Cilliers of Camelus Feeds in Oudshoorn advises on feeding ostrich chickens.

COETSEE, J. 2001. Weet so waar volstruiskuikenskoen druk. Landbouweekblad, 19: 14-15. Reports that ostrich farmers' profit on three month old chickens are very vulnerable to market price movements. If input costs are managed correctly, breeding birds are productive and the mortality rate kept at a minimum, possibilities are good for a profitable venture

COOPER, R.G. 2008. Proper incubation and hatching for healthy ostriches. World Poultry, 24: 30-31. The hygienic and incubation factors that assure successful hatching of healthy ostrich chicks are described, including egg disinfection, incubation temperature, egg weight and storage.

COOPER, R.G. 2001. Handling, incubation, and hatchability of ostrich (Struthio camelus var. domesticus) eggs: a review. Journal of Applied Poultry Research, 10: 262-273. Ostrich production is highly management intensive. Losses to producers commonly arise from infertile eggs, poor egg handling, and incorrect storage and incubator settings (temperature, relative humidity, and air flow). Early chick mortality is also a significant factor influencing

successful ostrich management. Microbial infection of ostrich eggs, caused by contaminated nests, inadequate egg cleaning, and poor incubator and hatchery sanitation, results in low hatchability. Adequate breeder nutrition is vital for ensuring fertility, increasing the number of eggs laid, and ensuring good survival rates of hatched chicks. The producer must work closely with veterinary extension officers, health laboratories, ostrich producer associations, researchers, and other farmers so that ostrich egg production is moulded into a process of excellence.

COOPER, R.G. 2000. Critical factors in ostrich (Struthio camelus australis) production: a focus on southern Africa. World's Poultry Science Journal, 56: 247-265. The aim of this paper is to highlight current application of new developments in ostrich production and describe the factors which are important for success. Ostrich production is highly management intensive. The ability to sustain long term profitability is dependent upon the use of strict management techniques by the producer and his workforce. Important factors include those favouring maximization of production, elimination of disease, reduction in transport and abattoir damage, and minimizing feed costs. Given the rise in the global competitiveness of the ostrich industry, the implementation of best practices on the farm is vital if the producer is to remain viable.

COOPER, R.G. 2000. Management of ostrich (Struthio camelus) chicks. World’s Poultry Science Journal, 56 (1) : 33-44.

COOPER, R.G., MAHROSE, K.M.A. & EL-SHAFEI, M. 2008. Spread bow leg syndrome in ostrich (Struthio camelus) chicks aged 2 to 12 weeks. British Poultry Science, 49: 1-6. The incidence of spread bow leg syndrome and associated pathology in 15 ostrich chicks aged 2, 4, 8 and 12 weeks is reported. Measurements were made of hind limbs: femur plus tibiotarsus; tarsometatarus; phalanx I, digit III; phalanx II, digit III plus phalanx III, digit III; and phalanx IV, digit III. A run was constructed (6 m × 1.7 m) and subdivided into 2 m sections and the time taken to traverse it was recorded. Measurements (cm) were made of the left and right footprints; the number of footprints and average stride length in 0 to 2, 3 to 4 and 5 to 6 m. Speed was calculated using distance run (m) divided by time taken (s). The number of steps was greater in bow leg chicks aged 4 and 8 weeks by comparison with healthy birds. Stride length, however, was smaller in all age groups with bow leg. All speeds in bow leg chicks were lower than those in healthy birds, except for that recorded at 2 m in chicks aged 2 weeks which did not differ markedly. In affected birds, feathers were sparse. Icterus was present. The tarsometatarsus was twisted, with severely inflamed joints, eroded distal ends, thickening of the cartilage and the presence of fibrous material surrounding the ligaments. Muscles in the hind limb were emaciated. The syndrome compromises the ability of chicks to keep up with adults in flocks, and may compromise their ability to escape predation.

COOPER, R.G. 2005. Bacterial, fungal and parasitic infections in the ostrich (Struthio camelus var. domesticus). Animal Science Journal, 76: 97-106. The ostrich is susceptible to microorganisms of bacterial, fungal and parasitic origin. Anthrax, caused by Bacillus anthracis, is dangerous to other livestock and humans, Salmonella is transmitted from rodents or wild bird reservoirs. Pausterellosis caused by Pasteurella multocida results in air sac infections in ostriches. Colibacillosis is caused by Escherichia coli. Tuberculosis caused by Mycobacterium avium, is very rare in ostriches. Aspergillosis principally afflicts chicks. Zygomycosis, a secondary fungal infection of the upper gastrointestinal tract, is caused by Basidia, Mucor and Rhizopus. Leucocytozoon struthionis and Plasmodium spp. are harmless Protozoa transmitted from flying arthropods. The tapeworm, Houttuynia struthionis, is dangerous in young ostriches. The adult ratite fluke (Philophthalmus gralli) is transmitted to ostriches following ingestion of infected freshwater crustaceans. Tick infestations of ostrich skin in Africa include Amblyomma spp., Haemaphysalis punctata, Hyalomma spp., Rhipicephalus turanicus and Argus spp. The ostrich quillmite (Pterolichus bicaudatus) and louse (Struthioliperus struthionus) may lower skin and leather quality via pruritis and/or excessive preening and feather loss. Nemododa infections are rare.

COOPER, R.G., HORBANCZUK, J.O. & FUJIHARA, N. 2004. (Review article): Viral diseases of the Ostrich (Struthio camelus var. domesticus). Animal Science Journal, 75: 89-95. The ostrich is an important animal in many livestock industries. A significant threat to this industry is losses from diseases. Newcastle disease is a notifiable, highly contagious viral infection of ostriches. Avian influenza may be transmitted from waterfowl, shorebirds and gulls to ostriches. Borna disease virus is a viral neurotropic infection spread mainly by rodents and felines. Crimean-Congo hemorrhagic fever is a viral disease transmitted by Hyalomma ticks to humans. Avipoxvirus afflicts ostrich chicks and is transmitted by mosquitoes or by direct contact with a pox lesion. Maintenance of a healthy and profitable enterprise requires the implementation, with assistance from the local veterinary authority, of comprehensive, practical and effective methods of health management and preventative medicine.

DURGUN, Z., KESKIN, E., COL, R. & ATALAY, B. 2005. Selected haematological and biochemical values in ostrich chicks and growers. Archiv fuer Gefluegelkunde, 69: 62-66.

In this study, some haematological and biochemical parameters were determined in healthy ostriches (Struthio camelus) of different ages. For this purpose 15 chicks and 13 growers obtained from a commercial hatchery in Konya environment were used. In blood samples, red blood cell counts, haemoglobin amount, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red blood cell size (mean corpuscular diameter), thrombocyte counts, white blood cell counts and percentage of leukocyte types were determined. Additionally, cholesterol, triacylglycerol, creatinine, creatinine kinase, glucose, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, total protein and albumin levels were measured in plasma samples. Although the red blood cell counts, haematocrit values, glucose levels and lymphocyte percentage of the chicks were lower than for growers, the heterophil percentage, total protein, cholesterol, triacylglycerol and creatinine kinase were higher than in growers. There was no significant difference in the other parameters investigated between chicks and growers. Based on the results, it was concluded that selected haematological and biochemical values were influenced by the age differences of the ostriches and the data obtained in the study could be useful to establish some baseline values for haematological and biochemical parameters in different ages of the ostriches.

DZOMA, B.M. & DORRESTEIN, G.M. 2001. Yolk sac retention in the ostrich (Struthio camelus): histopathologic, anatomic, and physiologic considerations. Journal of Avian Medicine and Surgery, 15: 81-89. Yolk sac retention or the failure to absorb yolk is a common problem in recently hatched ostrich chicks (Struthio camelus), and is one of the major causes of mortality in the first 2 weeks after hatching. In a study of 80 yolk sacs from dead-in-shell (DIS) eggs (n=24) and ostrich chicks up to 3 weeks after hatching (n=56), several aspects were considered. A predictive curve for normal growth and yolk absorption was calculated, and a histologic study of 'normal' and 'retained yolk' sacs was conducted. A microbiological evaluation of yolk sacs and the chicks was also performed. Findings were discussed in comparison to comparable data for poultry and in relation to possible causes of yolk sac retention. At necropsy, the diagnosis of retained yolk sac was made 13 times. No differences were observed by histopathologic examination between chicks with yolk sac retention and normal chicks. When the predictive curve was compared with direct observations at necropsy, the direct method had a sensitivity and specificity of 52 and 93%, respectively. Using the predictive curve, 19 yolk sacs were considered to be retained. Bacterial growth was found in the yolk of 42% of the DIS chicks, in 26% of the normal chicks, and in 22% of chicks with retained yolk sacs. In most cases, the same organism was also cultured from the liver of the chick. The bacterium most commonly isolated was Escherichia coli. Omphalitis could not be correlated with any of the isolates.

DZOMA, B.M. & DORRESTEIN, G.M. 2000. Veterinary problems of farmed ostriches up to 12 weeks of age: a review. Part II: Chick rearing. Zimbabwe Veterinary Journal, 31: 95-109.

EISENBERG, S.W.F., ASTEN, A.J.A.M., EDEREN, A.M. & DORRESTEIN, G.M. 2003. Detection of circovirus with a polymerase chain reaction in the ostrich (Struthio camelus) on a farm in The Netherlands. Veterinary Microbiology, 95: 27-38. This study describes for the first time the presence of circoviruses in ostrich tissue including embryos. A polymerase chain reaction (PCR) was used for the detection of the virus in liver samples. The use of a polymerase for low copy detection significantly increased the sensitivity of the test as well as a Southern blot. Viral DNA could be detected in chicks and eggs that did not hatch. For localization of the virus in the liver in situ hybridization was performed on a selection of positive liver tissues.

EL-ATTRACHE, J., VILLEGAS, P., O'CONNOR, B., BUHR, J.R. & ROWLAND, G.N. 2001. Adenovirus pathogenicity in immature ostriches. Avian Diseases, 45: 442-446. Two group I avian adenoviruses implicated as the possible cause of "fading chick syndrome" in ostriches less than 8 wk of age were isolated in primary chicken embryo liver cells. These viruses were identified by virus neutralization and further characterized by a pathogenicity trial in immature ostriches. The results showed that these isolates were non-infectious in ostrich chicks.

ENGELBRECHT, A., CLOETE, S.W.P. & WYK, J.B. 2008. Direct heterosis for liveweight and chick mortality in ostriches. Australian Journal of Experimental Agriculture, 48 (10): 1320-1325.

Ostriches from the South African Black (SAB) and Zimbabwean Blue (ZB) strains, raised to slaughter age in Oudtshoorn, South Africa, were used to investigate the possibility of improving the growth and survival of commercial ostriches through crossbreeding. Growth data from purebred and crossbred ostriches were analysed to estimate heterotic effects at different age intervals. Heterosis was significant at 1 month (P=0.017) and 14 months of age (P=0.03), and approached significance (P<0.071) at 7, 8 and 13 months of age. Different growth patterns were observed between the two purebred strains, with weight at 14 months differing significantly (SAB 89.6±0.9 kg v. ZB 98.3±4.5 kg). The weight advantage relative to SAB birds at this stage amounted to 10% for ZB, 11% for ZB × SAB and 13% for SAB × ZB (all P<0.05). Mortality to 30 days also showed significant heterosis (P<0.05). ZB birds had the highest mortality rate at 0.38±0.03, followed by the SAB × ZB (0.34±0.03), the SAB (0.27±0.01) and the ZB × SAB (0.23±0.02) strains. Results indicate that crossbreeding may be utilised to improve the growth and chick survival of commercial ostriches. The breed combinations should be assessed for other productivity traits to determine the viability of a structured crossbreeding program.

ERHUI, J., KEMEI, P., HUI, S., YAN, W., SHENGHE, L., LAN, W., LI, T., ANNA, D. & JIAXIANG, W. 2008. The morphological observation of the respiratory organs in African ostrich chicks. Chinese Journal of Veterinary Science, 28: 553-556. The morphological characteristics of the respiratory organs in African ostrich chicks were observed by gross anatomy and histology. The mucosa of palatum durum was smooth, on which few papillae were distributed. A couple of mucosa reductus were observed in the ringent wall of choanae which was situated in the pharyngeal portion. The broad and serrated marginal arytenoid cartilage was concrescent with the annular cartilage. The trachea mucosa had a small quantity of goblet cells in the epithelium. Moreover, some homeocytes were present in its lamina propria, which was a layer of dense connective tissue. The cartilagines tracheales was C-shaped, and 5-6 pieces of the cartilage flap were composed of the bronchial cartilage. The atrium were small, and did not lay out radiatively with the centre of the parabronchus. Numerous blood vessels were present in the respiration capillary. These results indicated that the inspiratory organs in ostrich chicks were still immatured, and its structure was more peculiar.

ESSA, F. & CLOETE, S.W.P. 2006. Survival and growth of purebred South African black and Zimbabwean blue ostriches and their reciprocal cross. Instituto Prociência, Minas Gerais,

Brazil, Proceedings of the 8th World Congress on Genetics Applied to Livestock Production, Belo Horizonte, Minas Gerais, Brazil, 13-18 August, 2006, : 10-03. The growth and survival of purebred SAB and ZB ostrich chicks, as well as chicks derived from the reciprocal cross between these lines was investigated. The survival and day-old, 3 month, 5 month, 9 month and slaughter weights of the chicks were recorded and analysed by Chi-square and least squares procedures. Linear contrasts were computed to get an indication of heterosis. The survival of SAB and ZB × SAB chicks was improved relative to that of the ZB and SAB × ZB chicks. SAB chicks displayed the lowest day-old and slaughter weight and ZB chicks the highest. The crosses performed intermediate between the pure lines with a heterosis of 6.5% occurring at 9 months. Crossbreeding has the potential to improve the survival of ZB birds and to improve the slaughter weight of SAB birds. Further research is required to validate these findings and to provide a framework for exploiting heterosis. FAIR, M.D., WYK, J.B. & CLOETE, S.W.P. 2005. Parameter estimates for production traits of ostrich females within breeding seasons. World Poultry Science Association (WPSA), Beekbergen, Netherlands, Proceedings of the 3rd International Ratite Science Symposium of the World's Poultry Science Association (WPSA) and 12th World Ostrich Congress, Madrid, Spain, 14th-16th October, 2005, : 21-27.

Data involving monthly records of egg production (EP), chick production (CP), hatchability (H), mean egg weight (MEW) and mean day old chick weight (MCW) were analysed using REML procedures. All traits were treated as hen traits. In preliminary analyses it was shown that monthly phenotypic EP patterns differ between young (2-year old) and older breeding females. EP of young birds increased to reach a peak of approximately 4-5 eggs per month relatively late in the breeding season (September to December). Older hens reached a higher peak of 6-9 eggs per month earlier in the breeding season (August to September). There was a secondary peak in older birds from November to December. All birds except two year olds exhibited evidence of a slump of production during October. The random effects of animal, temporary environment (TE - unique hen within a year) and service sire (SS) were estimated from the data. Heritability estimates (±s.e.) were 0.14±0.03 for EP, 0.14±0.03 CP, 0.59±0.04 for MEW, 0.56±0.05 for MCW and 0.20±0.04 for H. Corresponding estimates for TE were 0.16±0.01, 0.17±0.01, 0.13±0.01, 0.09±0.01, and 0.18±0.02. The effect of SS was significant but relatively low for all traits, ranging from 0.06±0.02 EP to 0.12±0.03 for MCW. Monthly EP and CP were highly correlated at all levels, ranging from 0.71±0.03 for the TE correlation to 0.91±0.04 for the genetic correlation. EP was favourably correlated with H on a genetic level (0.55±0.13). The genetic correlations of EP and CP with MEW and MCW were variable and in some cases antagonistic as is often found in poultry. The genetic correlations of H with MEW and MCW were positive (0.26±0.12 and 0.34±0.12 respectively). As expected, the genetic correlation of MEW and MCW was very high at 0.85±0.03. The results indicate selection for improved reproduction in ostriches is possible. Selection for reproduction is unlikely to be complicated by unfavourable correlations with H, MEW and MCW.

FASONE, V. 2002. Effect of the utilization of vetch leaves (Vicia sativa L.) in the diet on the productive performance of ostrich chicks (Struthio camelus australis). Rivista di Avicoltura, 71: 29-31. Two groups of Blue Neck ostriches were fed on diets with 10-13% vetch leaves (A) or 10-13% lucerne leaves (B) during 90 days. Data are presented on liveweight gain after 30, 60 and 90 days and feed conversion. Growth of chicks fed on diet B was better.

GALIP, R. & POYRAZ, O. 2003. Hatching results of ostriches under the conditions of Middle Anatolian. Lalahan Hayvancilik Arasturma Enstitusu Dergisi, 43: (1) : 35-46.

The hatching results of ostrich eggs produced in the Middle Anatolian Region, Turkey, was studied. Results showed that hens produce eggs from March to August. Average egg weight was 1583 g. Egg weight from new layers were lower than older layers. The average infertility

rate was 18.63%. The average chick weight was 1067 g, which consisted of 65-67% of egg weight. The malposition and embryonic mortality rates for the first and second years were 8.10 and 5.81%, and 14.29 and 15.48%, respectively.

GLATZ, P.C. & MIAO, Z.H. 2008. Husbandry of ratites and potential welfare issues: a review. Australian Journal of Experimental Agriculture, 48 (10) : 1257-1265. Since the mid-1980s, there has been worldwide farming of ratites, particularly with ostriches, emus and rheas for feathers, meat, skin and oil. Most of these ratites are produced commercially outside their native habitat. This has raised concerns about welfare, particularly whether birds are provided the five freedoms: food and water; shelter; health care; alleviation of pain and suffering; and the freedom of movement. This paper reviews the factors that influence bird welfare before hatch with breeder, egg and hatchery management and after hatch with brooding and rearing systems, stocking density, handling, transport, disease and slaughter. Assessment of bird welfare in each of the production sectors in the industry is based on how well the five freedoms are being met. The review identifies egg handling practices and hatchery hygiene that can have a major impact on the subsequent health of hatched chicks. In addition, feeding of appropriate diets, reducing stocking density and improving housing can improve bird health and freedom of movement. When the husbandry practice of toe trimming is not practiced according to the best practice method, chronic pain may result and impair walking ability of birds. Stress and injuries to birds can be reduced when birds are handled correctly on farm and in the lairage and are transported using appropriate vehicles. Farmers, transporters and abattoir staff can have a major impact on maintaining bird welfare if best practice farming systems and husbandry practices are implemented.

HAMANN, F. 2004. Incubation and hatching in German ostrich farms. Veterinarski Fakultet Sveučilišta u Zagrebu (Faculty of Veterinary Medicine, University of Zagreb), Zagreb, Croatia, Proceedings of the 11th Ostrich World Congress, Island Great Brijun, Croatia, 15-17 October 2004, : 29-32.

This article discusses the natural and artificial incubation of ostrich eggs, hatching rates, causes for losses/embryo mortality during incubation, the proper use of incubators and incubation hygiene in Germany.

HAMANN, F. 2004. Ostrich farming in Germany: chick rearing and chick diseases. Veterinarski Fakultet Sveučilišta u Zagrebu (Faculty of Veterinary Medicine, University of Zagreb), Zagreb, Croatia, Proceedings of the 11th Ostrich World Congress, Island Great Brijun, Croatia, 15-17 October 2004, : 40-42. The problems in chick rearing are not caused by climatic factors or by its susceptibility to diseases but by the lack of knowledge of the farmers. Inadequate hygiene (especially in farms with mixed animal stock) or deficient nutrition often lead to growth problems of various kinds. Based on our experience, there must be thorough training of every person intending to start ostrich farming. The training of veterinarians as well as the scientific research in farms, focusing on preventive medicine and biosecurity, would be helpful to secure the health of German ostrich flocks. A solid know how as well as adequate management are important prerequisites for any successful ostrich farming venture and the well-being of the animals.

HASSAN, S.M., SIAM, A.A., MADY, M.E. & CARTWRIGHT, A.L. 2005. Egg storage period and weight effects on hatchability of ostrich (Struthio camelus) eggs. Poultry Science, 84: 1908-1912. We studied the affects of storage period and egg weight on the hatchability of 314 ostrich (Struthio camelus) eggs. Eggs were stored at 20°C and 65% RH before incubation at the Poultry Research, Teaching and Extension Center at Texas A&M University (College Station, TX). Eggs were classed by storage period (≤5, >5≤10, >10≤15, or >151,450≤1,650, or >1,650 g) to determine the influence of storage period and egg weight on hatchability, egg weight loss, incubation period, and absolute and relative chick

weights. Eggs were incubated at 36.5 to 37.0°C and 25% RH through 38 d of incubation and 36°C and 30% RH thereafter. Mean egg weight loss was greater from eggs of the longest storage period group (>151510≤15 d was not different from eggs stored ≤10 d or >1515 d than was observed in eggs stored ≤15 d. Negative correlations were detected between egg weight and moisture loss at 38 d (-0.55) and between hatch time and moisture loss (-0.25). Hatchability was higher in small eggs than medium eggs (≤1,650 g). A positive correlation was observed between chick and egg weights (0.84). The results indicated that storage period and egg weight affected egg weight loss. Our results suggested that the most effective storage period was less than 15 d to maintain hatchability for ostrich eggs when incubated at 36.5 to 37.0°C with 25% RH.

HEMALATHA, S., GOVINDARAJAN, R., MANOHAR, B.M., VENGADABADY, N. & PURUSHOTHAMAN. 2006. Omphalitis in ostrich chicks. Indian Veterinary Journal, 83: 452-453. Postmortem examinations were conducted on 10 ostrich chicks from Malaysia that died over a period of 2 weeks after their arrival in Tamil Nadu, India [date not given]. The chicks were part of a group of 100 birds. The gross pathological and histopathological findings are described. Retained yolk sac and Klebsiella spp. and Escherichia coli infections were found, which were most likely the causes of death in the chicks and indicates poor hatchery management and/or retrograde infection of the yolk sac by gastrointestinal pathogens.

HEMALATHA, S., GOVINDARAJAN, R., MURALI MANOHAR, B., VENGADABADY, N. & PURUSHOTHAMAN. 2006. Omphalitis in ostrich chicks. Indian Veterinary Journal, 83: 452-453.

HEMALATHA, S., RAMESH, S., TENSING, G. & PURUSHOTHAMAN, V. 2007. Leg problems in ostrich chicks. Tamilnadu Journal of Veterinary and Animal Sciences, 3: 166-168. This paper reported on the leg problems encountered in ostrich chicks brought for necropsy examination. 18 ostrich chicks aged 2 months to one year were brought for postmortem examination at the Central University Laboratory, Madhavaram, Chennai, Tamil nadu. The birds had a history of lameness, recumbency, pressure sores on the legs, inappetence and sudden death. 11 males and 7 female died due to leg problems. Postmortem examination revealed fractures of tibiatarsus (n=3), fracture of tarsometatarsus (n=1), fracture of both tibiatarsus and tarsometatarsus (n=2), tibiotarsal rotation (n=2) and slipped gastrocnemius tendon from the condyles of hock joint with dislocation of joint (n=10). Apart from the leg problems, all birds except for 2 revealed severe haemorrhagic enteritis, hepatitis or both. The incidence of leg problems was greater in male chicks than in female chicks. Moreover, young chicks between 2 and 6 months of age were most commonly affected. Mostly, the left leg was involved in fractures. All the birds with fractures of bones also suffered from severe enteritis and hepatitis. The damage to the intestines and liver probably led to poor absorption of nutrients, resulting to the birds being more prone to fractures.

HORBANCZUK, J.O. & SALES, J. 2000. Influence of assistance during hatching on the mortality and growth rate of ostrich chicks. Archiv fuer Gefluegelgelkunde, 64: 40-41.

The effects of assistance during hatching on survival and growth to 60 days of age of ostrich chicks was investigated (location and dates not given). 240 eggs from 14 females were incubated under standard conditions, sanitized after collection, stored for a maximum of 9 days at 12°-15°C and sanitized again before setting. On day 39 viable eggs were transferred to the hatcher. 36 chicks received assistance at hatching and 63 were not assisted. The chicks were reared in indoor pens at a density of 0.8 m²/chick from 1 to 30 days of age and 1.2 m²/chick from 30 to 60 days of age. From 4 weeks of age the chicks had access to outdoor pens. The initial temperature was 32.5°; this was reduced by 2° per day to 23-24°. Feed concentrate was provided ad lib., supplemented with lucerne from 2 weeks after hatching; fresh water was continually available. Chicks were weighed at 1, 3, 7, 10, 14, 21, 30, 40, 50 and 60 days of age. There were no significant differences in mortality between assisted and unassisted chicks but chicks that had received assistance had a slightly higher mortality rate between 15 and 60 days after hatching. Assistance during hatching had no effect on growth rate.

HORBANCZUK, J.O. 2000. Improving the technology of artificial incubation of ostrich (Struthio camelus) eggs with reference to biological aspects. Prace i Materiały Zootechniczne, Zeszyt Specjalny, 10 : 1-90. This study aimed at improving the artificial incubation of ostrich eggs by determining the optimum parameters for temperature, relative humidity, position of the egg during incubation and frequency of egg turning in the incubator. An attempt was made to determining the optimum storage length and conditions for hatching eggs before their placing in the setter. An examination of the frequency of malpositions of the embryo within the egg and a pathomorphological analysis of dead embryos was made. The studies were conducted at the Garczyn Ostrich Farm, near Gdan´sk, Poland. The analyses included 2400 hatching eggs obtained during 3 laying seasons (1996-1998) from 24 females. The highest hatchability was obtained from eggs stored at 12-18°C over a period not longer than 7 days, incubated at a constant temperature of 36.4° and a relative humidity of 30% with the eggs placed vertically and turned every hour. Storing eggs up to 12 days at 15° also proved acceptable. The highest hatchability was obtained from eggs weighing less than 1800 g and with shells up to 2.1 mm thick. Hatchability decreased markedly when eggs weighed below 1200 g and the shell thickness was below 1.1 mm. The curve of embryo mortality was similar during all years and had 2 peaks, the first before day 6 and the second after day 35 of incubation. The most frequent malpositioning of embryos was with the head in the small end of the egg (44.3%). Nearly 2/3 of dead embryos proved to be in an incorrect position. Up to 60% of them had limited access (or no access at all) to the air cell, which lead to hypoxia and death. The most common abnormalities of dead embryos were malpositioning within the egg (64.9%), unretracted yolk sac (29.3%) and oedema of the neck and legs (34.3%). In chicks hatched with deformities the most common was an unretracted yolk sac (55.4%) and oedema of neck and legs (52.3%). A new malposition was identified and described, with the embryo lying correctly within the egg but the beak twisted onto its back and turned towards the small end of the egg. The mortality of embryos in this position reached 100% but it occurred only in 1.3% of eggs. Optimization of egg storage and incubation rendered it possible to improve the hatchability of fertile eggs (from 74.8% in the first year to 79.1% in the third), decrease the mortality of embryos (mainly during the last 14 days of incubation), lower the percentage of abnormal chicks from 6.3 to 3.8%, lower by 5.3% the share of malpositioned embryos and by 4.4% the share of chicks requiring assistance at hatching. Introducing optimum conditions for storing hatching eggs and for incubation may increase the hatchability of set eggs by about 10% and of fertile eggs by 7%.

HORBANCZUK, J.O., PARADA, R., HUCHZERMEYER, F.W. & PLAZA, K. 2004. Four-legged ostrich (Struthio camelus) chick. Veterinary Record, 154: 736.

HORBANCZUK, J.O., PERELMAN, B. & COOPER, R.G. 2001. Twins from single-yolked ostrich (Struthio camelus var. domesticus) egg. Animal Science Papers and Reports, 19: 167-171. On 28 September 2000 at Garczyn Farm in Poland a case of ostrich twins occurred, in an egg containing single yolk. The egg was laid on August 12, 2000, by a 38-month old female in her second year of production, during the final stages of laying (egg 46 out of a total of 51 eggs laid in the year 2000). The twin-bearing egg was the heaviest egg laid by this female throughout the laying season and its morphological parameters were recorded: mass - 1885 g, length - 168.1 mm, width - 138.7 mm and shape index - 82.5. On day 43 of incubation the egg was opened. One chick (twin 1) was still alive for several hours after removing from the shell, whereas the other (twin 2) was dead-in-shell. The surviving chick had begun pipping and had reached the air space. The embryos were situated with their ventral surfaces opposed with the yolk sac which was positioned between them. Each embryo was fully formed and with complete feathers. The twins weighed 504.9 g (twin 1) and 368.6 g (twin 2).

HORBANCZUK, J.O. 2004. Selection and standard of hatching ostrich eggs as recommended in Europe. Veterinarski Fakultet Sveučilišta u Zagrebu (Faculty of Veterinary Medicine, University of Zagreb), Zagreb, Croatia, Proceedings of the 11th Ostrich World Congress, Island Great Brijun, Croatia, 15-17 October 2004 : 11-15.

The selection of ostrich eggs for incubation in terms of optimal egg weight and egg shell thickness, location and depth of the air shell and the influence of these factors in chick embryonic development and egg hatchability are discussed.

HUI, S., KEMEI, P., SHENGHE, L., YAN, W., LAN, W., LI, T., ANNA, D., ERHUI, J. & JIAXIANG, W. 2007. Microstructure and ultrastructure of spleen and distribution of 5-HT in spleen of ostrich chicks. Scientia Agricultura Sinica, 40: 2861-2868. This article reports on an experiment which examines the microstructure and ultrastructure of the spleen in ostrich chicks. Using light and transmission electron microscope the spleen capsule was observed to be thin and peritrabecular was underdeveloped, the periarterial lymphatic sheath in white pulp was thin, there were splenic nodules occasionally while no germinal centre was observed. The lymphocyte with rich mitochondria, free ribosomes and RER in the cytoplast had double membrane and obvious nuclear pores. There were obvious demarcation line which was composed of acidophilic matter between the ellipsoids and the peripheral lymphatic tissues. The distribution of 5-HT immunoreactive cells was also investigated using immunohistochemical methods.

IPEK, A. & SAHAN, U. 2002. The effects of egg weight on the hatching characteristics of ostrich eggs. Turk Veterinerlik ve Hayvancilik Dergisi, 26: 723-728.

In the following investigation, egg weight (small=1200-1400 g, medium=1401-1600, large>1600 g) was found to significantly affect the hatchability of fertile eggs and hatchability of total eggs (P<0.01). Hatchabilities of fertile eggs were 67.74, 74.42 and 64.28%; and hatchabilities of total eggs were 43.75, 50.00, and 41.86% for the small, medium and large egg weight groups, respectively. The effects of egg weight on early, mid and late embryonic death were also significant (P<0.01). Early embryonic death rates were 9.68, 9.30 and 10.91%; mid embryonic death rates were 6.46, 4.65 and 7.35%; and late embryonic death rates were 16.12, 11.63 and 17.46% for the small, medium and large weight groups, respectively. Egg weight significantly affected egg weight loss (P<0.05). Eggs with medium weight exhibited a weight loss of 13.94%, which was close to the optimum. The effect of egg weight on chick weight was also significant (P<0.01). Chick weight increased as the egg weight increased. Hatching time was significantly influenced by egg weight (P<0.05). Incubation time was longer for the large egg weight groups compared with the small or medium weight groups.

IJI, P.A. 2008. Intestinal development and nutrient utilisation in the ostrich: a brief review. Australian Journal of Experimental Agriculture, 48: 1280-1283.

The ostrich industry is plagued by a high level of neonatal mortality among chicks that are under 3 months of age. Although ostrich chicks hatch with a gastrointestinal tract that is more than 10% of their liveweight, there appear to be deficiencies in structural and functional development of the intestinal mucosa (and possibly pancreatic function) that do not support adequate digestive function. There is also insufficient knowledge of the nutritional requirements of the ostrich, which results in the provision of diets that may not be suitable, particularly for the hatchlings. Recent evidence suggests that ostrich chicks under the age of 10 weeks have poor ability to digest fibre. Further evaluations have revealed generally low activities of amylase, trypsin and lipase in ostrich chicks within the first 10 weeks of life. It is not certain if digestive function can be improved by supplementation with microbial enzymes, which are routinely used by the poultry industry. There is still a paucity of data on the digestive physiology of the ostrich and areas of intervention through applied nutrition are still vague. This paper reviews existing knowledge of the digestive physiology of the ostrich and examines the potential of interventions that could reduce neonatal mortality in the species.

IORDANIDIS, P.I., PAPAZAHARIADOU, M.G., GEORGIADES, G.K., PAPAIOANNOU, N.G. & FRYDAS, S.E. 2003. Cloacal prolapse in ostrich chicks with histomoniosis. Veterinary Record, 153: 434-435. Ostrich chicks (two 23-day-old and two 2-month-old) in Thessalonica, Greece were presented

for cloacal prolapse [date not given]. All other ostriches and chickens from the same farm were physically normal. The birds were euthanized, after which liver, spleen and intestine samples were obtained for culture and the faeces were subjected to parasitological investigations. It was shown that the cloacal prolapse was the only significant clinical sign. No other histopathological changes were detected and liver, spleen and intestine cultures were negative. Faecal examination revealed trophozoites of Histomonas meleagridis. No helminths were found in the alimentary tract of the birds examined. It is suggested that the chickens may have been involved in the transmission of the parasite and that the cloacal prolapses may have been associated with a causative agent other than H. meleagridis.

IPEK, A. & SAHAN, U. 2004. Effect of breeder age and breeding season on egg production and incubation in farmed ostriches. British Poultry Science, 45: 643-647. 1. This research was carried out to investigate changes in egg production and hatchability as influenced by age and breeding season of 10 trios (two females, one male) of ostrich (Struthio camellus) during 1998 to 2002. 2. Breeding season affected number of eggs laid per female per season, average egg weight, length of laying period and clutch sequence. 3. The number of eggs laid per female per season was 25 in the first breeding season and 57 by the fifth breeding season. The laying period lasted 169 d in the first season whereas it was 210 d by the fifth season. The breeding season became longer year by year. 4. The number of clutches was two in the first season, three in the second and 4 in the later breeding seasons: the mean interval between cycles was 9 to 10.6 d and the mean number of eggs in one cycle varied from 12 to 14.4. 5. The breeding season affected the hatchability of fertile eggs, chick weight at hatching, hatchability of total eggs, fertility, malpositioned embryos, deformed chicks and assisted chicks during hatching. The first 4 variables increased and the last three decreased, with each breeding season. 6. Weight loss of eggs and length of incubation were unaffected by the breeding season. Hatchability which was 64.3% in the first season increased progressively and reached 73.1% in the fifth breeding season.

ISLAM, M.Z., ISMAIL, K. & BOUG, A. 2008. Re-introduction of the red-necked ostrich, Struthio camelus camelus, in Mahazat as-Sayd Protected Area in central Saudi Arabia. Zoology in the Middle East, 44: 31-40. As the Arabian Ostrich Struthio camelus syriacus, a distinct subspecies, became extinct in the wild during the mid-20th century, the most closely related subspecies, S. c. camelus occuring in north-eastern Africa, has been chosen for reintroduction into Saudi Arabia. A few individuals of this Red-necked Ostrich were obtained from Sudan in 1988-89 from a private collection, and in 1994 a few birds were translocated to Mahazat as-Sayd Protected Area into a 25 ha fenced enclosure. So far a total of 96 Red-necked Ostriches has been released into the fenced Mahazat as-Sayd and the estimated population is between 125 and 150 individuals. Since captive flocks of Ostriches were translocated to Mahazat, their survival rate increased by >41% up to the end of 2000. On an average 22-30 chicks are hatched annually. A total of 137 Ostriches was recorded dead over the period of 13 years during the drought period. Both captive-bred and wild-born adults and young died of starvation and thirst, despite being provisioned with alfalfa and water during several years.

JANJECIC, Z., MUZÌC, S., DRAZÌC, M. & SOKOLOVIC, M. 2003. Production performance on "Fistrek" ostrich farm. Stocarstvo, 57: 187-193.

Over the recent years, the number of ostrich producers in the Republic of Croatia is growing. The exact record of this production in Croatia was not adequately kept, thus, the objective of this trial was to examine the reproductive and productive performance of ostrich production on an average farm. Two separate ostrich families of one male and one female bird were studied in this trial, as well as records of 120 females from co-operative farms of the Noster d.o.o. Company. Two breeding families at the Fištrek family farm laid on average 43 eggs in 165 days, with an average egg weight of 1.42 kg. From these eggs, an average of 37 chicks hatched (the average hatchability was 85.77%). Average weight of chicks at 30 days was 5073.36 g and feed conversion was 2.15 kg. Mortality during the first 30 days was 3.00%. 120 females from the co-operative produced 4128 eggs (35 eggs per bird on average), with 68.25% of fertilized eggs. Hatchability of the fertilized eggs was 62.50%, while the total

hatchability was only 42.75%. Based on this performance and its comparison to production results achieved throughout the world, it is concluded that the examined production level is about average world level but shows some room for improvement.

JELENA, R., SIMPRAGA, M., ZADRO, R. & LUZAR-STIFFLER, V. 2007. Haematological status of one-day old ostriches (Struthio camelus domesticus). Acta Veterinaria, : 57(2-3):231-239. Measurement of haematologic and biochemical parameters is an important part of evaluating the health of ostrich chicks. Thus aimed to determine haematological and biochemical parameters in the blood of one-day old ostriches in intensive breeding. The blood count, iron and copper concentrations were determined in 30 clinically healthy, one-day old unsexed ostriches of the domesticated subspecies of ostrich Struthio camelus domesticus. Their importance in clinical evaluation and disease condition is discussed. In this study the following mean values were determined in 30 clinically healthy, one-day old unsexed ostriches: erythrocyte count = 1.48 x 1012/L, MCV = 126.6 fl, MCH = 52.9 pg, MCHC = 418 g/L, haemoglobin concentration = 79 g/L, haematocrit = 18.87%, platelet count = 8.6 x 109/L, leucocyte counts 9.1 x 109/L, heterophils = 82%, eosinophils = 0.5%., basophils = 2.5%, lymphocytes = 11%, monocytes = 3.4%, iron = 4 mmol/L and copper = 2.6 [mu]mol/L. We hope that the data presented in this study will be an incentive to clinicians and scientists in the field, to use haematological and biochemical examinations as an aid to the diagnosis of diseases in ostriches.

JIN, E.H., PENG, K.M., WANG, J.X., DU, A.N., TANG, L., WEI, L., WANG, Y., LI, S.H. & SONG, H. 2008. Study of the morphology of the olfactory organ of African ostrich chick. Anatomia Histologia Embryologia, 37: 161-165. The anatomy and histology of the olfactory organ of African ostrich chick were carefully observed by gross anatomy observation, paraffin sectioning and haematoxylin-eosin (HE) staining. The results showed that there were no keratotic nose lids at the entrance of the external naris, and that the nasal cavity was separated into two imperforate compartments by the nasal septum. The posterior conchae were connected with the middle conchae without cohering to nasal walls, and appeared to be part of a palinal elongation of the middle conchae. Olfactory cells were distributed in the mucosal epithelium of middle and posterior conchae. Nasal glands were shaped like irregular rectangles, and their connective tissue extended to the parenchyma, which was divided into many glandular lobules. The layers of the olfactory bulb were indistinct, the globular structure was inconspicuous and the granular cells were scattered relatively in the lamina granularis externa.

KANYARI, P.W.N., NGATIA, T.A., MATHIU, P.M., OYEJIDE, A. & SRIVASTAVA, K.K. 2005. Some causes of poor performance and chick mortality in farmed ostriches in Alabama [USA] and Kenya. The Kenya Veterinarian, 28: 6-10. Commercial ratite farming is rapidly becoming a desirable alternative source of profitable meat production among small holder farmers. However, ratite ranching, particularly ostrich production is severely constrained by a very high chick mortality rate (up to 40%). To help rural farmers, including those in developed countries such as the United States, gain a successful foothold in this potentially lucrative farming enterprise, the causes of chick mortality must be identified and controlled. The present collaborative study was designed to characterize and compare causes of mortality in chicks in small holder ratite farms in Macon and adjoining counties of Alabama and some selected localities in Kenya between 1997 and 2000. The study established that, in both Alabama [USA] and Kenya, ostrich farmers incur losses of considerable magnitude from a wide range of causes, some of which could not be established. Losses were experienced right from the embryonic stages whereby embryos developed poorly causing death before hatching. In USA, hatchability was 72% while in Kenya, hatchability was only 56% on average. In Kenya, a high mortality rate in the early weeks of life (<3 weeks) [27-40%] was noted. Pathogens isolated at postmortem from inflamed tissues and septic yolk sacs were mainly common bacteria such Enterobacter sp., Escherichia coli, Staphylococcus, Streptococcus sp., Pseudomonas sp., Corynebacterium sp. and Clostridium sp. Other causes of death were impaction, dehydration, generalized oedema, joint infection and non-specific peritonitis. Limb deformities constituted the main cause of culling among the chicks. Histopathological lesions were observed in virtually all organs examined including the

abdominal, thoracic and even the brain tissue. Lesions associated with circulatory disturbances were common. Bacteriological analysis of feeds in Kenya showed that bacterial contamination of feed, especially fish meal, was quite possibly a cause of infection.

KIMWELE, C.N. & GRAVES, J.A. 2003. A molecular genetic analysis of the communal nesting of the ostrich (Struthio camelus). Molecular Ecology, 12: 229-236. The ostrich breeding system is complex and unique; communal clutches are laid by several females, although only one female, the major female, and the resident territorial male provide parental care. More eggs are laid in the nest than can be incubated and the major female ejects surplus eggs from the incubated central clutch. Microsatellite markers were used to analyse the parentage of communal nests in Nairobi National Park. This revealed that major females contributed a disproportionate number of fertile eggs to the central, incubated clutch and that multiple paternity and maternity within a nest were common; 68.9% of all incubated eggs on a nest were not parented by both the resident territorial male and the major female of that nest. All the males fertilized eggs on the clutches of neighbouring males. Unexpectedly, every major female with her own nest was also simultaneously a minor female with incubated eggs on neighbouring clutches. The relatedness between females laying in the same nest was not significantly different from the population average and significantly less than that between chicks hatched from the same nest.

KNOBL, T., BACCARO, M.R., MORENO, A.M., GOMES, T.A.T., VIEIRA, M.A.M., FERREIRA, C.S.A. & FERREIRA, A.J.P. 2001. Virulence properties of Escherichia coli isolated from ostriches with respiratory disease. Veterinary Microbiology, 83: 71-80. Eight Escherichia coli isolates from ostriches with respiratory disease were investigated for the presence of genes encoding the following adhesins: type 1 pili (fim), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afaI), temperature regulated adhesin, curli (crl, csgA) and temperature-sensitive hemagglutinin (tsh). Genes for heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf), alpha-haemolysin (hly) and aerobactin (aer) production were also investigated. Other characteristics investigated were the presence of hemagglutination activity, growth on an iron-deficient medium, aerobactin production, serum resistance, adherence to chicken tracheal cells, pathogenicity for day-old chicks, and serogroup. Serogrouping showed that four isolates belonged to serogroup O2, two to serogroup O78, one to serogroup O9, and one to serogroup O21. The virulence genes found were: fim in all eight isolates, csgA in seven, aer in six, and pap, crl and tsh in one isolate each. All isolates analyzed were positive for mannose-resistant hemagglutination, adhered in vitro to ciliated tracheal epithelium, grew on iron-deficient medium, and showed serum resistance. Pathogenicity tests on day-old chickens revealed one highly pathogenic isolate, three of low pathogenicity and four isolates with intermediate pathogenicity.

LOPES, M.A.E., FERREIRA, C.S.A. & FERREIRA, A.J.P. 2005. Use of competitive exclusion in ostrich chicks, and the economical benefits. Proceedings of the 3rd International Ratite Science Symposium of the World's Poultry Science Association (WPSA) and 12th World Ostrich Congress, Madrid, Spain, 14th-16th October, 2005 : 307-311.

Front of the mortality of chicks that are notice in the breedings around the world, solutions were studied to be possible to reduce the losses. One of the solutions to minimize this losses is the use of competitive exclusion. The competitive exclusion were produced from benefits bacterias isolated of ostrich enteric flora. And that bacterias show to be very effective in prevention of pathogenic bacteria infection, reducing the mortality, besides the increase of the weight gain and better absorption of yolk sac. The decrease of mortality, according to the studies and tests done in the field, reached about 30 to 40% in different conditions for the breeds. The weight gain increased 49% and demonstrated that the animals could use better the offered feed. The reduction of the mortality associated with better weight gain of birds leads to a increase of profits in 54%, from approximately US$ 8400,00 to US$ 13.000,00 in 100 birds hatched.

MAGIGE, F.J., MOE, B. & ROSKAFT, E. 2008. The white colour of the Ostrich (Struthio camelus) egg is a trade-off between predation and overheating. Journal of Ornithology, 149: 323-328. Most ground nesters lay pigmented eggs, and egg pigmentation generally matches the environment. Pigmentation of eggs has evolved as a protective device against predation, but dark-pigmented eggs can be susceptible to overheating when exposed to solar radiation. The Ostrich (Struthio camelus) lays white eggs that are unattended for the first few weeks before incubation, and are quite visible to predators. To evaluate the effect of colour on the surface and core temperatures, we painted some Ostrich eggs dark brown or white, and left some unpainted (control), and exposed all of them directly to the sun during the day. The surface and core temperatures of brown eggs were significantly higher than those of the white-painted and control eggs. In addition, the core temperature of brown eggs exceeded 37.5°C, which is the temperature at which embryo mortality starts to increase. In a second experiment, we placed eggs (brown-painted and control) in various types of vegetation to study their visibility to an observer walking towards them. The white eggs were discovered from a significantly longer distance than the brown eggs, indicating that the predation risk may be much higher for white eggs. The results thus suggest that white eggs minimise overheating and allow the Ostrich to leave its eggs unattended before incubation starts, but they are more susceptible to predation.

MALAGOJUNIOR, W., FRANCO, H.M., MATHEUCCI JUNIOR, E., MEDAGLIA, A. & HENRIQUE-SILVA, F. 2002. Large scale sex typing of ostriches using DNA extracted from feathers. BMC Biotechnology, 2 (19) (1 October 2002) : 1

Background: Ostrich (Struthio camelus) breeds have been gaining increasing significance around the world. The large-scale sex determination of chicks is an important task in the development of these breeds. To date, two PCR-based methods have been established for ostrich sex typing, neither of them intended for large-scale analyses. Here, we report on a protocol adapted to carry out large-scale gender scoring using DNA obtained from chick feathers. Results: The DNA was extracted using a fast and simple alkaline extraction protocol that provided sufficient template for an early diagnosis. Tests with several primer sets enabled us to determine the best internal control primers associated with the sex-specific primers, avoiding spurious bands. Using DNA extracted from a single bulb and the best set of primers, we applied this protocol to simultaneously sex-type 96 individuals accurately. Conclusion: We have established a fast, safe, accurate and inexpensive procedure for large-scale sex typing of ostriches using DNA extracted from feathers. This procedure is useful for the gender identification of chicks in the first days of nestling life.

MALECKI, I.A., RYBNIK, P.K. & MARTIN, G.B. 2008. Artificial insemination technology for ratites: a review. Australian Journal of Experimental Agriculture, 48: 1284-1292. In ratite farming, the low male to female ratio in the mating system restricts genetic improvement and prevents reduction of the number of males kept on-farm for fertilisation of the female flock. These issues can be overcome and the industry can better realise its potential by using artificial insemination (AI) technology. It is the only practical method for intensive genetic improvement of reproduction and the production of eggs, chicks, oil, meat and leather. For AI to be feasible, we need reliable methods for semen collection, artificial insemination, prolonged storage of spermatozoa in the female tract, high rates of lay, efficient protocols for semen storage, and a panel of quantitative methods for measuring true fertility and hatchability, sperm supply rates in vivo and sperm viability in vitro. For both emus and ostriches, prolonged sperm storage in females has already been demonstrated. Methods for semen collection and artificial insemination, using animal-friendly techniques, have also been developed. Semen storage and cryopreservation protocols are yet to be optimised and we still need to overcome the male-dependent rate of lay, but adoption of AI technology by the ratite industries is now feasible. It also seems likely that these technologies will be relevant to wild ratites that need intensive conservation efforts, such as cassowaries, rheas and ostrich subspecies.

MEYER, A., CLOETE, S.W.P. & BROWN, C.R. 2003. The influence of separate-sex rearing on ostrich behaviour and skin damage. South African Journal of Animal Science, 33: 95-104. Separate-sex rearing of slaughter ostriches was investigated as a management strategy to minimize skin damage. Day-old ostrich chicks were divided into three treatment groups (a group of mixed-gender and two single-sex groups, one male and one female). At three months of age, because of the large variation in live weights, the birds were sorted within treatment according to weight. Each gender treatment was represented by six replications and each weight class treatment was represented by nine replications. At slaughter, chest circumference, slaughter weight, carcass weight, skin weight, skin area and skin grading were recorded. The only slaughter trait that was affected by gender treatment was skin weight without fat, with all-male groups having significantly heavier skins than all-female groups. Behavioural observations, carried out at nine and 13 months of age, indicated that aggression was more prevalent in all-male groups compared to all-female and mixed-gender groups. The all-female groups had the lowest levels of aggression. Diurnal time-activity budgets were largely unaffected by the gender composition of the groups. Evaluation of the skins at slaughter showed that kick marks on the area outside of the crown were more prevalent in all-male groups, indicating that increased aggression was associated with increased kicking behaviour which led to skin damage. However, because of the location of the kick marks, skin grading was not influenced. Weight class treatment also affected the prevalence of kick marks. Aggression and kick marks on the skin were generally more pronounced in the groups comprising the heavier chicks, suggesting that body weight may have an important effect on hormone levels and aggressive behaviour. Because of the general lack of improvement in the skin grading of the ostriches due to the increased skin damage in all-male groups when separated, it is concluded that the practice of separate-sex rearing has no definite benefits for slaughter ostrich production and product quality.

MEYER, A., CLOETE, S.W.P., BROWN, C.R. & SCHALKWYK, S.J. 2003. The persistence to slaughter age of scars resulting from damage inflicted to ostrich skins during the grow-out phase. South African Journal of Animal Science, 33: 32-37. Damage to ostrich skins in the form of cuts and scratches obtained during the grow-out phase results in lower quality skins that fetch lower prices. This represents major financial losses to the ostrich industry. The stage at which such damage occurs and its persistence to slaughter age, when it affects skin grading, is not known. In this study we assessed the persistence through to slaughter age of wounds inflicted on the skins of ostrich chicks at ages 1, 4, 7, 10 and 13 months. Superficial and deep wounds were investigated by either scratching the skin with a nail, or by cutting through the skin with a scalpel blade. Experimental animals were slaughtered at either 11 or 14 months of age and visible scars were assessed on the processed skins. The length and surface area of each scar were measured to obtain an adjusted scar size. Orientation of lacerations (dorso-ventral or anterior-posterior) proved to be unimportant. Cut wounds were persistent to slaughter as were scratch marks, with only a small percentage of scratch wounds incurred at a young age not persisting to slaughter age. Mean scar size at slaughter became smaller with an increase in age at which the wounds were inflicted, except at 13 months of age where it was assumed that the wounds had not had sufficient time to heal properly. Deep cut wounds caused larger scars at slaughter age than superficial scratch damage. It seems that both superficial (scratches) and deep (cuts) wounds will result in lower skin grading, irrespective of age of infliction. This indicates that changes in chick rearing practices are necessary to reduce the incidence of skin damage if skin quality is to be improved.

MEYER, A., CLOETE, S.W.P., BROWN, C.R. & SCHALKWYK, S.J. 2002. Declawing ostrich (Struthio camelus domesticus) chicks to minimize skin damage during rearing. South African Journal of Animal Science, 32: 192-200. Leather is one of the main products derived from ostrich farming. Current rearing practices lead to a high incidence of skin damage, which decreases the value of ostrich skins. In the emu and poultry industry, declawing is commonly practiced to reduce skin damage and injuries. We consequently investigated declawing of ostrich chicks as a potential management practice to minimize skin lesions that result from claw injuries. A group of 140 day-old ostriches was declawed and a second group of 138 chicks served as the control. The two

groups were reared separately to slaughter but were rotated monthly between adjacent feedlot paddocks to minimize possible paddock effects. Overall, the declawed group had fewer scratch and kick marks on the final processed skin than the control group, which resulted in the proportion of first grade skins in the declawed group being more than twice that of the control group. Behavioural observations at 9 and 13 months of age indicated that declawing resulted in no impairment in locomotive ability or welfare. There was a tendency for the declawed group to have higher average liveweights towards the end of the growing-out phase that resulted in a 3.7% higher average skin area at slaughter than in the control group. Survival to slaughter was independent of the treatment group but absolute means favoured the control group. In conclusion, declawing does not compromise the wellbeing of ostriches and has a significant benefit in terms of the quality and the grading of the skin, with important economic implications for ostrich farmers.

MINKA, M.S. & AYO, J. 2007. Road transportation effect on rectal temperature, respiration and heart rates of ostrich (Struthio camelus) chicks. Veterinarski Arhiv, 77: 39-46. The responses of rectal temperature (RT), respiratory rate (RR) and heart rate (HR) of ostrich (Struthio camelus) chicks during road transportation were investigated using standard recording procedures. The RT and RR of the ostriches increased significantly (P 0.05) from the value of 68.5 ± 2.2 beats per minute recorded during the journey. The RT, RR and HR values recorded six hours after the journey were not significantly (P > 0.05) different from the corresponding pre-transportation values of the ostriches. The results showed that transportation of ostrich chicks for four hours induced a transient increase in RT and RR values. It is concluded that road transportation of ostrich chicks for four hours apparently has no adverse effects on health and performance of ostrich chicks (Copyright applies to all Abstracts.)

MINKA, N.S. & AYO, J. 2007. Road transportation effect on rectal temperature, respiration and heart rates of ostrich (Struthio camelus) chicks. Veterinarski Arhiv, 77: 39-46. The responses of rectal temperature (RT), respiratory rate (RR) and heart rate (HR) of ostrich (S. camelus) chicks during road transportation were investigated using standard recording procedures. The RT and RR of the ostriches increased significantly (P0.05) from the value of 68.5±2.2 beats per minute recorded during the journey. The RT, RR and HR values recorded 6 h after the journey were not significantly (P>0.05) different from the corresponding pre-transportation values of the ostriches. These results showed that transportation of ostrich chicks for 4 hours induced a transient increase in RT and RR values. In conclusion, road transportation of ostrich chicks for 5 h apparently has no adverse effects on health and performance of ostrich chicks.

MUSHI, E.Z., BINTA, M.G. & CHABO, R.G. 2004. Yolk sac utilization in ostrich (Struthio camelus) chicks. Onderstepoort Journal of Veterinary Research, 71: 247-249. The mass of residual yolk sac expressed as a percentage of initial mass of the egg from which the chick hatched decreased sharply in the first 2 days post-hatching. A gradual reduction occurred between 3 and 10 days after which a sharp decline was noted between 11 and 13 days post-hatching. The highest number of chicks with unabsorbed yolk sac was noted on day 5 post-hatching followed by days 6 and 7. Chick mortality followed the same pattern. The dynamics, causes and clinical consequences of yolk sac utilization are discussed.

MUSHI, E.Z., BINTA, M.G., CHABO, R.G. & TOTO, P.A.S. 2003. A note on endoparasites of wild ostriches (Struthio camelus) in the Mokolodi Nature Reserve, Gaborone, Botswana. Journal of the South African Veterinary Association, 74: 22-23. A study was undertaken to investigate the prevalence of endoparasites of wild ostriches at Mokolodi Nature Reserve, Gaborone, over a 7-month period. Large numbers of strongyle eggs were recovered from faecal material in April and September and a decline in the strongyle egg counts was evident during June and July. Noteworthy was the absence of helminth eggs in faecal samples collected from chicks and coccidia oocysts from any of the ostriches.

NAVARRO, J.L. & MARTELLA, M.B. 2002. Reproductivity and raising of Greater Rhea (Rhea americana) and Lesser Rhea (Pterocnemia pennata) - a review. Archiv fuer Gefluegelkunde, 66: 124-132. The greater rhea (Rhea americana) and the lesser rhea (Pterocnemia pennata) are ratites that have conservation and economic relevance. The two most common schemes for rearing adult rheas are the captive or intensive condition in pens (used by most zoos and farms) and the semi-captive or semi-intensive condition in large breeding paddocks. Understanding the demography of rheas is necessary to design management strategies for these species and to help decision making at farms and captive breeding programmes. The median total number of eggs produced per season by greater rhea females under captive condition (40 eggs) is higher than that of lesser rheas (18 eggs). Greater rheas also show a higher egg production under captivity than in semi-captivity (24 eggs). The hatching success of greater rheas is higher in captivity (median=60%) than in semi-captivity (45%) or in the wild (30%), whereas lesser rheas show the opposite trend (captivity=51%, wild=60%). Finally, the estimated number of surviving chicks in autumn produced per female rheas are lower than that of other ratites: ostrich=14 chicks; emu=11 chicks; cassowaries=9 chicks; greater rheas=8 chicks and lesser rheas=4 chicks. Reproductive parameters of all ratites reported in most scientific works show to be more moderate than those commonly claimed in general or commercial literature. Although both rhea species show a comparatively low productivity, incorporating specific management practices suggested in this work into the different rhea production schemes can substantially improve egg laying, hatchability and survival of chicks and adults.

NGATIA, T.A., KANYARI, P.W.N., MATHIU, P.M., SRIVASTAVA, K.K., WILSON, S.T. & OYEJIDE, A. 2004. Postmortem observations on ostrich chicks in a commercial farm in Kenya. Bulletin of Animal Health and Production in Africa, 52: 59-62.

NITZAN, R., BARKAI, D., NITSAN, Z. & LANDAU, S. 2002. Intake, growth and carcass characteristics of young ostriches given concentrates with and without pasture. Animal Science, 74: 71-79. Although ostriches are herbivores, their diets in commercial farming in Israel consist mainly of concentrates. The objective of this study was to evaluate an alternative for fattening ostriches aged 10 to 30 weeks, which combines pasture with concentrate feeding. Chicks were allotted to three treatments. Diet of group C40 consisted of concentrate only, provided at 40 g/kg body mass (m(b)). Groups CG20 and CG30 received concentrate at 20 and 30 g/kg m(b), respectively, and grazed 4 to 6 h/day on lush green alfalfa (Medicago sativa), sown barley (Hordeum vulgare), natural pasture or sulla (Hedysarum coronarium). During the last 10 weeks of experiment, groups CG20 and CG30 were merged into one group, managed as CG20 and grazed natural pasture, sulla, alfalfa, or vetch (Vicia sativa). Ostriches from group CG20 and CG30 consumed 390 (s.e. 30) g and 260 (s.e. 20) g DM per day at pasture, i.e. 0.46 and 0.28 of their total daily intake, respectively. Pasture intake for CG20 was higher (P < 0.05) than for CG30. Intake of pasture (both grazing treatments combined) was twice as much as on natural pasture or alfalfa as on barley. These results were consistent with the ostriches' preference for forbs rather than grasses in the natural pasture. The mean organic matter digestibility was 0.84 (s.e. 0.01), ostriches gained at 347 (s.e. 13) g/day, and the food conversion ratio was 3.05 (s.e. 0.16), with no effect of group. Also, grazing did not affect the dressing rate (0.47, s.e. 0.015) or the size and mass of the different parts of the gastro-intestinal tract, with the exception of the glandular and muscular stomachs, which were proportionately 0.4 (P < 0.05) heavier in grazing birds. Lower (P < 0.05) fat content (33.8 v. 26.5 g/kg) but not tenderness, of a selected muscle (fibularis longus) was found for grazing birds. This study suggests that, in young ostriches, grazing lush green pasture may reduce concentrate intake by proportionately 0.4, without altering growth performance or carcass yield and quality.

OFRI, R., MILLODOT, S., SHIMONI, R., HOROWITZ, I.H., ASHASH, E. & MILLODOT, M. 2001. Development of the refractive state in eyes of ostrich chicks (Struthio camelus). American Journal of Veterinary Research, 62: 812-815. The objective of the study is to follow the development of the refractive error in the eyes of ostrich chicks from age 0 to day 37 after hatching. Spot retinoscopy was conducted to assess

refractive error in ostrich chicks. Seventy eyes of 35 ostrich chicks were examined. Of these, 18 chicks were followed over time. At least 4 serial measurements (at 2- to 7- day intervals) were conducted in each of these chicks from day 1 to 37 after hatching. Seventeen additional chicks were examined on days 0, 3, 12, and 19 after hatching. Ostrich chicks were myopic at hatching, with a mean±SD refractive error of -4.47±0.15 diopters (D). The refractive error rapidly decreased during the first week of life, and by day 7 after hatching, chicks were slightly hyperopic, with a mean refractive error of 0.42±0.12 D. After day 7, there were no significant differences in the mean refractive error. The development of optics in the ostrich eye appears to be unique among animals and is characterized by myopia at hatching, rapid onset of emmetropia, and minimal variation in refractive error among chicks.

ORENGE, C.O., MATHIU, P.M. & MBUGUA, P.N. 2002. Nitrogen retention as an indicator of metabolic utilization of nitrogen in three months old ostrich chicks (Struthio camelus massaicus). African Journal of Ecology, 40: 399-400.

Five 3-month-old ostriches (S. camelus massaicus) (3 females and 2 males) were used in this experiment conducted in Kenya. They were fed ad libitum on a commercial diet with a crude protein content of 17.50%. Total mixed excreta samples were collected to calculate nitrogen balance, and hence, nitrogen retention. A preliminary period of 2 weeks was allowed for the birds to become accustomed to the diet, after which, excreta samples were collected for 5 days. Nitrogen balance was positive for all ostriches, and ranged from 147.5 to 583.1 mg kg-0.75 per day (mean, 432.2±81.3 mg kg-0.75 per day). Nitrogen retention rate ranged from 13.6 to 43.3% (mean, 32.14%). The ratio of nitrogen balance:nitrogen intake was used as an indicator for the rate of nitrogen retention in the body, and thus, as a measure of metabolic utilization of nitrogen. The relatively high rate of nitrogen retention observed in this study could be a physiological adaptation enabling the ostrich to thrive well in arid and semi-arid environments.

PERELMAN, B. 2004. Control and prevention of hatchery related infectious diseases in ostriches. Veterinarski Fakultet Sveučilišta u Zagrebu (Faculty of Veterinary Medicine, University of Zagreb), Zagreb, Croatia, Proceedings of the 11th Ostrich World Congress, Island Great Brijun, Croatia, 15-17 October 2004: 63-65.

This article discusses incubator and hatchery hygiene and egg handling and disinfection procedures to prevent contamination and infection of ostrich eggs and embryos by bacteria and fungi.

PERELMAN, B., FUCKS, D., HELLER, D. & SCHONFELD, M. 2001. Nutrition related micrognathia in ostriches. Israel Journal of Veterinary Medicine, 56: 135-140. This article presents the first report of nutritional related micrognathia in ostrich chicks caused by an apparent deficiency in the feed of the parent flock. It was characterized by low hatchability, late embryo mortality, leg deformation and severe micrognathia. These signs were observed in ostrich eggs and new hatched ostrich chicks from one breeding farm located south of Israel. These problems were not observed in eggs or chicks originating from other ostrich farms incubated in the same setters and hatchers, in the same hatchery, at the same time. It was noted that on the farm where the affected eggs came from, the breeding flock of ostriches were fed with a self-prepared feed without vitamin and mineral supplement.

PONCE GORDO, F., CORRALECHE, L., GARCIA DURAN, B. & MARTINEZ DIAZ, R. 2001. First findings of Houttuynia struthionis (Cestoda: Davaineidae) in ostriches (Struthio camelus) hatched and raised in Spain. Research and Reviews in Parasitology, 61: 79-82. The first reports of the presence of the cestode Houttuynia struthionis (Houttuyn, 1773) in ostriches (Struthio camelus) hatched and raised out of Africa are presented. Five young

ostriches hatched in Spain at different times and raised in two different farms, were found at post-mortem analysis parasitized by several cestodes. These parasites were identified as H. struthionis (Cyclophyllidea: Davaineidae). Furthermore, proglottids of this cestode were found in fecal samples from Spanish hatched, two to four months old ostrich chicks from a third farm. The data available indicate that this parasite can be introduced and its life cycle established in importer countries out of Africa, probably using autochtonous species as intermediate host. There is no information available about which cestode stage (adult, cysticercoid) first entered Spain.

RAHMANIFAR, F., MANSOURI, S.H. & GHAZI, S.R. 2008. Histomorphometric study of the spinal cord segments in the chick and adult male ostrich (Struthio camelus). Iranian Journal of Veterinary Research, 9: 336-340, 392-393. In this study, the vertical, transverse and oblique diameters of the spinal cord segments (C1, C6, C12, C18, T1, T4, L1, L4, L6 and L8) and the ratio of gray matter to white matter in chick (1 month) and adult (18 months) male ostriches, each group consisted of 3 animals, were measured with standard micrometric method using 6 µm thick sections by light microscope. With advancement of age, the ratio of gray matter to white matter was reduced but the diameters of spinal cord segments were increased. Statistically, there were significant differences in parameters measured between the two age groups (P<0.05).

RAIDAL, S.R., GILL, J.H. & CROSS, G.M. 1996. Pox in ostrich chicks. Australian Veterinary Journal, 73: 32-33.

RAINES, A.M., KOCAN, A. & SCHMIDT, R. 1997. Experimental inoculation of adenovirus in ostrich chicks (Struthio camelus). Journal of Avian Medicine and Surgery, 11: 255-259.

REZAKHANI, A., KOMALI, H., MOKHBER-DEZFOUL, M.R., ZARIFI, M., GHABI, M., ALIDADI, N. & NADALIAN, M.G. 2007. A preliminary study on normal electrocardiographic parameters of ostriches (Struthio camelus). Journal of the South African Veterinary Association, 78: 46-48. Electrocardiograms were taken from 100 normal healthy male and female ostriches which were 1 to 15 months old using a base apex lead. The heart rate of those less than 3 months old ranged from 107 to 250 beats per minute with a mean of 171.47 [plus or minus] 9.03 and that of ostriches of more than 3 months old ranged from 43 to 167 with a mean of 90.52 [plus or minus] 2.64 beats/minute. The P-waves were positive in all cases except in 1 ostrich which it was isoelectric. The ORS complexes were mainly negative and either monophasic (QS) or biphasic (rS or RS). The T-wave showed more variation than other waves. The durations of P P-R, QRS, Q-T and T-waves of chicks and of those more than 3 months of age (4-15-month-old) were 0.04 [plus or minus] 0.00, 0.06 [plus or minus] 0.00; 0.14 [plus or minus] 0.04,016 [plus or minus] 0.00; 0.04 [plus or minus] 0.00,0.06 [plus or minus] 0.00; 0.18 [plus or minus] 0.00,0.27 [plus or minus] 0.00 and 0.06 [plus or minus] 0.00,0.09 [plus or minus] 0.01 s, respectively, and amplitudes of the main direction of P-, QRS and T-waves of 2 groups were 0.29 [plus or minus] 0.02, 0.26 [plus or minus] 0.01; 1.87 [plus or minus] 0.17, 2.21 [plus or minus] 0.08; and 0.34 [plus or minus] 0-06, 0.37 [plus or minus] 0.02 mV, respectively. Ten cases showed cardiac dysrhythmias of which 9 showed sinus arrhythmia and 1 showed premature atrial contractions (PAC). This study showed that the base apex lead can be a suitable monitoring lead for electrocardiographic examination of ostriches.

RICHARDS, P.D.G., BOTHA, A. & RICHARDS, P.A. 2002. Morphological and histochemical observations of the organic components of ostrich eggshell. Journal of the South African Veterinary Association, 73: 13-22. The organic component of the avian egg shell can be divided into 3 portions: the shell membrane, matrix and cuticle. These have been well characterized in the chicken, but little has been published with regard to the ostrich Struthio camelus egg shell. A number of recent studies have indicated that the cause of intra-shell embryonic deaths in the ostrich is similar to intra-shell embryonic deaths that occur in the chicken. These deaths in the chicken are associated with the loss of or damage to the waxy cuticle and other organic components of the egg shell, which is reported to be absent in the ostrich egg shell. In this study, preliminary

morphological and histochemical analyses, at the level of the light and electron microscope, have characterized the various organic components of the ostrich egg shell. Results of histochemical and electron microscopical analyses suggest that there may only be one shell membrane in this species, which could play a major role in the limitation of bacterial penetration into the embryonic chamber. The shell membrane has a distinct elemental profile as determined by EDS analysis. The matrix is shown to decrease in mesh size from the mammillary layer to the vertical crystal layer. The closer packing of the mesh may indicate the presence of a morphologically discernible termination signal to calcification or the remnants of an evolutionary calcified cuticle. The matrix of the pores may also form a defensive barrier against bacterial invasion, which could be damaged as a result of dipping the eggs before incubation.

RIZZI, R., ERBA, M., GIULIANI, M.G., CEROLINI, S. & CERUTTI, F. 2002. Variability of ostrich egg production on a farm in Northern Italy. Journal of Applied Poultry Research, 11: 332-337. In Italy, ostrich breeding is a growing business, due to consumer demands for alternative meat, but little information is available on egg production. The purpose of this study was to describe productive and reproductive performance on an ostrich farm in northern Italy and to identify factors influencing egg and chick weight. Eggs were collected from five trios (one male per two females), incubated, and candled at 13, 26, and 38 days. Egg weight was recorded at collection, at set, and at each candling. Chicks were weighed at hatch. Fertility was 69.7%, whereas hatchability of egg set and of fertile eggs were 51.5 and 73.9%, respectively. Egg weight was 1558 and 1530 g at collection and at set, respectively, and the mean egg weight loss (14.2%) from set to 38 days was in the normal range for ostriches. There was a positive association between egg weight at collection and both egg weight during incubation and chick weight. Egg weight at set and at first candling decreased as storage time increased (-3.5 and -2.9 g/day, respectively). Eggs laid in March were heavier and had the greatest weight losses. Results show that the main source of variability for egg weight as well as fertility and hatchability was the trio rather than environmental conditions.

SAHAN, U. 2003. Near-term embryonic mortality during artificial incubation of the ostrich eggs. Indian Veterinary Journal, 80: 1002-1005. A total of 72 ostrich eggs which failed to hatched at the end of the incubation period were studied (Turkey). Oedema and malposition were the predominant symptoms. 56 (77.77%) of 72 embryos were affected by oedema, and 26 (36.11%) were determined to be malpositioned. Other symptoms were noticed in less than 10% of chicks examined.

SAHAN, U., IPEK, A. & YILMAZ, B. 2004. Effects of storage length on incubation results of ostrich eggs (Struthio camelus). Archiv fuer Gefluegelkunde, 68: 187-190.

The purpose of this study was to examine the effects of preincubation storage of ostrich eggs on hatchability, egg weight loss, length of incubation and chick weight at hatching. A total of 210 ostrich eggs were stored at 18°C for 10 days (1-2, 3-4, 5-6, 7-8 and 9-10 d). The effects of storage length on hatchability of fertile eggs was significant (P<0.01). Hatchability declined with storage length, for maximum hatchability at less than 7 d of egg storage appears to be best. Hatchability of fertile eggs was 71.4, 72.4, 70.4, 65.4 and 60.7% for the storage length groups, respectively. Early embryonic mortality rates (10.7, 10.3, 11.1, 15.4, 17.9%; P<0.01) and late embryonic mortality rates (14.3, 13.8, 14.8, 15.4 and 17.9%; P<0.01) were also significant for the storage length groups, respectively. Egg weight loss increased with increased storage length (P<0.05). Egg weight loss up to day 38 of incubation averaged 12.99% for eggs that hatched. The effects of storage length on chick weight at hatching and length of incubation was also significant (P<0.05). The chick weight tended to decline in relation with storage time up to 7 days. Chick weight at hatching averaged 66.8% and 65.0% of initial egg weight for the 1-2 to 9-10 d storage length, respectively.

SAMSON, J. 2000. Study of hatching problems in farmed ostriches. Large Animals Review, 6: 65-71.

SCHULZE, C., GROSSMANN, E. & KRONE, O. 2006. Case report: Libyostrongylus douglassii-associated proventriculitis in ostriches in Germany. Fallbericht: Libyostrongylus douglassii-assoziierte Magenentzuendungen bei Straussen (Struthio camelus) in Deutschland. DTW Deutsche Tieraerztliche Wochenschrift, 113: 240-242. Cases of Libyostrongylus douglassii-associated proventriculitis in an adult female ostrich and two ostrich chicks occurring on two farms in different federal states of Germany are described. The adult bird was recently bought and kept under quarantine conditions without contact to other animals of the herd. Without developing clinical signs of illness, the animal died. At necropsy, typical lesions of wireworm infection were found. The lining of the stomach had a moth-eaten appearance. Massive amounts of adult stages of trichostrongyloid nematodes were diagnosed in histological specimens of the proventricular mucosa and under the koilin layer of the ventriculus. The worms were isolated from the proventriculus and identified as L. douglassii. The feces of the bird contained high amounts of typical eggs of the worms with a medium size of approximately 70 x 40 [mu]m. A polyphasic degeneration of heart and skeletal muscle was diagnosed in addition to the wireworm infection and interpreted to be a result of a malnutrition (Vit. E-/selenium deficiency). The ostrich chicks were reared on another farm and submitted for necropsy because of high mortality (8 out of 12 chicks died). A massive invasion of the proventricular mucosa with L. douglassi was macroscopically and histologically detected at necropsy of the anaemic birds.

SEBEI, S.K. & BERGAOUI, R. 2009. Ostriches' reproduction behaviour and mastery of natural incubation under farming conditions. Tropical Animal Health and Production, 41: 353-361. This study describes the ostriches' behaviour in natural incubation and two key elements to improve this way of reproduction: artificial introduction of eggs in the nest and modifying the nest location when not adequate. Six females and 3 males were observed during four reproduction seasons. The results show that it is possible to lead ostriches change the nest. Eggs incubation was the male and the main female's responsibility; the second female of the trio shared this task in 85% of cases. Presence of eggs incited ostriches to sit in the nest. Incubation per se began when the couple took turns in a regular way to perform this role; mating and laying stopped. Hatching was marked by a higher aggressiveness among parents who watched over the nest to ensure the hatching of late eggs and continued to sit in the nest as long as there were eggs. The mean fertility and hatchability of set eggs were 58.68 and 41.55% respectively. Fertile eggs had less than 12 days of storage when introduction into the nest. Viability at 3 months of the chicks kept with their parents was higher than that of the chicks reared by our care (82% and 57% respectively).

SHIVAPRASAD, H.L., KIM, T.J., WOOLCOCK, P.R. & TRIPATHY, D.N. 2002. Genetic and antigenic characterization of a poxvirus isolate from ostriches. Avian Diseases, 46: 429-436. Avian poxvirus was isolated from nodules on the heads and conjunctiva of two 3-to-4-wk-old ostrich chicks. The ostriches from which poxvirus was isolated had been placed on premises where turkeys that had shown evidence of poxvirus infection had been raised earlier. Microscopically, the nodules from the ostriches were composed of proliferating and hypertrophic epithelial cells that formed large fronds. Most of the hypertrophic epithelial cells contained large eosinophilic intracytoplasmic inclusion bodies characteristic of poxvirus. Characterization of the avian poxvirus isolated from the cutaneous lesions in ostriches was based on western blotting of virus antigen, restriction fragment length polymorphism of genomic DNA, pathogenesis, and cross-protection studies in chickens. Antigenic and genetic studies did not reveal any significant difference between the poxvirus isolated from ostriches (PVO) and fowl poxvirus (FPV). Further, susceptible chickens immunized with the PVO were protected when challenged with a virulent strain of FPV. Thus, the poxvirus isolated from ostriches had similar antigenic, genetic, and biological properties to FPV.

SHIVAPRASAD, H.L., WOOLCOCK, P.R., MCFARLAND, M.D., CURTIS, M. & KARABATSOS, N. 2002. Turlock-like bunyavirus associated with encephalomyelitis and myocarditis in an ostrich chick. Journal of Veterinary Diagnostic Investigation, 14: 363-370.

SHOURESHI, P., BARON, A., SZYNSKIE, L. & DORES, R.M. 2007. Analyzing the evolution of [beta]-endorphin post-translational processing events: studies on reptiles. General and

Comparative Endocrinology, 153: 148-154. In many cartilaginous fishes, most ray-finned fishes, lungfishes, and amphibians, the post-translational processing of POMC includes the monobasic cleavage of [beta]-endorphin to yield an opioid that is eight to ten amino acids in length. The amino acid motif within the [beta]-endorphin sequence required for a monobasic cleavage event is -E-R-(S/G)-Q-. Mammals and birds lack this motif and as a result [beta]-endorphin(1-8) is a not an end-product in either group. Since both mammals and birds were derived from ancestors with reptilian origins, an analysis of [beta]-endorphin sequences from extant groups of reptiles should provide insights into the manner in which [beta]-endorphin post-translational processing mechanisms have evolved in amniotes. To this end a POMC cDNA was cloned from the pituitary of the turtle, Chrysemys scripta. The [beta]-endorphin sequence in this species was compared to other reptile [beta]-endorphin sequences (i.e., Chinese soft shell turtle and gecko) and to known bird and mammal sequences. This analysis indicated that either the loss of the arginine residue at the cleavage site (the two turtle species, chick, and human) or a substitution at the glutamine position in the consensus sequence (gecko and ostrich) would account for the loss of the monobasic cleavage reaction in that species. Since amphibians are capable of performing the ss-endorphin monobasic reaction, it would appear that the amino acid substitutions that eliminated this post-translational process event in reptilian-related tetrapods must have occurred in the ancestral amniotes.

SIMPRAGA, M. 2004. Proceedings of the 11th Ostrich World Congress, Island Great Brijun, Croatia, 15-17 October 2004. : 1-132. This paper contains conference proceedings on ostrich rearing, including egg incubation and hatching; chick rearing and diseases and nutritional practices in ostrich chick rearing.

SIMPRAGA, M., RAUKAR, J. & NOVAK, I.L. 2004. Calcium, phosphorus and magnesium levels and alkaline phosphatase activity in the blood of one-day-old ostriches. Veterinarski Arhiv, 74: 177-188. Considering that climatic conditions, feeding and holding conditions as well as microflora and microfauna vary from one country to another, standard values of individual ostrich health status indicators should be established on a country to country basis. This particularly applies to ostriches at their earliest stage when they are extremely sensitive to stress induced by temperature fluctuations, initial feeding (starting), change of feeding regime, imbalanced ration composition, holding pen overpopulation, etc. Potential consequences include death or abnormal growth and development from the very beginning. It is widely known that problems associated with abnormalities in skeleton development, such as fibiotarsal rotation, reduce the young chick's resilience and increase the likelihood of its premature death and/or failure to meet production requirements. Calcium, phosphorus and magnesium metabolism disorder is one of the recognized causes of skeletal development problems. Since the available literature does not provide any information on calcium, phosphorus and magnesium levels and ALP activity in one-day-old ostriches, these elements were set as the objective of our research. The research was carried out on 10 healthy, one-day-old, unsexed ostriches of the variety Struthio camelus domesticus. The results have shown that calcium, phosphorus and magnesium levels were 2.33 mmol/L, 4.56 mmol/L, and 0.76 mmol/L, respectively, and ALP activity was 251.63 U/L. These results, although obtained on a relatively small number of birds, represent a valuable contribution to ostrich physiology because they may serve as reference values when investigating calcium, phosphorus and magnesium metabolism and/or abnormalities in skeletal development in these animals.

SOLEY, J.T., VAN WILPE, E., AIRE, T.A. & OZEGBE, P.C. 2005. The morphology of the seminiferous tubules in the three-day-old ostrich chicks. Microscopy Society of Southern Africa Proceedings, 35: 60.

SPEER, B. 2006. Ratite medicine and surgery. Proceedings of the North American Veterinary Conference, January 7-11, 2006, Orlando, Florida. Small Animal edition, vol. 20 : 1596 -1597.

Brief description of ostrich, rhea, emu and cassowary paediatrics.

SUGAHARA, K. 2003. Energy utilization of growing chicks in various nutritional conditions. Asian-Australasian Journal of Animal Sciences, 16: 903-909. For the last two decades, energy utilization of growing chicks has been studied more and more. This paper focuses on the energy utilization estimated by the metabolizable energy (ME) values and the efficiency at which ME is used for growth of chicks under various nutritional environment. Degree of saturation of dietary fats is responsible for nitrogen-corrected apparent metabolizable energy (AMEn) of fats. The effect of dietary fat sources on heat production depends on the kind of unsaturated fatty acids as well as the degree of saturation. Medium chain triglyceride shows lower AME and net energy than long chain triglyceride. Phytase as feed additives increases the AME values of the diet along with improvement of the phosphorous utilization. Ostriches have higher ability to metabolize the energy of fibre-rich foodstuffs than fowls. Their higher ability seems to be associated with fermentation of fibre in the hindgut. Proportions of macronutrients in the diets have influenced not only the gain of body protein and energy but also the oxidative phosphorylation of the chicken liver. Essential amino acids deficiency reduces ME/GE (energy metabolizability) little, if any. Growing chicks respond to a deficiency of single essential amino acids with the reduction of energy retained as protein and increased energy retained as fat. Thus, energy retention is proportional to ME intake despite deficiency, and efficiency of ME utilization is not affected by deficiency of amino acids. Effect of oral administration of clenbuterol, a beta-adrenergic agonist, on the utilization of ME varies with the dose of the agents. Although the heat production related to eating behaviour has been estimated less than 5% of ME, tube-feeding diets decreases HI by about 30%.

THOMPSON, K.F. & BINKS, S. 2001. Will the big birds fly? New Zealand Society of Animal Production, Hamilton, New Zealand, Proceedings of the New Zealand Society of Animal Production 61: 42-44.

Modern ostrich farming in New Zealand commenced in 1994 with importation of eggs. In 1997 the first processing of ostrich meat for the domestic market occurred. By 1999 there were estimated to be 2500 breeding hens, 12 000 chicks and 10 000 rising 1-year-old birds. The current domestic market for ostrich meat is about 100 tonnes annually and there has been an increase of 70% in the last 12 months. About 4000 yearling birds provide meat for the domestic market. Export of ostrich to Europe commenced in 2000. At current prices the limiting constraint is achieving 15 slaughter birds per hen each year. Slaughter birds need to be over 95 kg liveweight. The quality of hen nutrition is considered as a critical factor influencing embryonic mortality and chick survival. The target rate is being achieved by some farmers but for this to be an industry average, further developments in breeding hen nutrition and young chick survival will be required.

THOMPSON, K.F., LUCAS, S., FURLONG, J.M. & SYKES, A.R. 2008. Survey of plasma and liver mineral concentrations and enzyme activities in ostriches (Struthio camelus) under farmed conditions in New Zealand. New Zealand Veterinary Journal, 56: 222-226. AIM: To generate clinical biochemical data to aid diagnosis of suboptimal performance in ostriches farmed under pastoral systems in New Zealand. METHODS: Blood and liver samples were sought from three categories of bird, viz 3-12-week-old chicks, 7-12-month-old growers, and from breeding hens, managed under pastoral conditions on farms in several locations in New Zealand. Concentrations of the minerals Ca, PO4, Mg, Na, K, Cu and Zn, activities of the enzymes gamma-glutamyl transferase (GGT), creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST), and concentrations of total protein (TP) and uric acid and vitamin E in plasma and Se in whole blood were determined from four flocks of chicks, two flocks of growing and one flock of breeding birds. Concentrations of Cu, Fe and vitamin B12 were determined from liver samples from chicks and growing birds. Bodyweight was recorded at the times of blood-sampling, where this was feasible. RESULTS: It proved impossible to obtain blood samples by venepuncture of the radial vein from chicks <3 months of age. Plasma concentrations of minerals, with the exception of K, which were higher, were within the normal range observed in the literature for ratite species. Activities in plasma of AST and CK were almost double, and those of LDH similar, to those in the literature for

ostriches. There was considerable variation in activities of the enzymes between farms, but no association with growth performance. Concentrations of Cu in plasma were lower and in liver were higher than would be expected in farmed ruminants. Though hindgut fermenters, the birds maintained concentrations of vitamin B12 in plasma and liver at least comparable to those observed in ruminants. CONCLUSIONS: Collection of blood samples by venepuncture via the wing in ostrich chicks younger than 3 months of age is difficult and unlikely to prove viable for routine diagnostic purposes. Clinical biochemistry data on mineral nutrients in ostriches farmed in New Zealand are similar to those in the literature from South Africa, but AST and CK are higher, and may be normal and a reflection of the high growth rates of the musculoskeletal system.

THOMPSON, P.N., SINCLAIR, M. & GANZEVOORT, B. 2008. Risk factors for seropositivity to H5 avian influenza virus in ostrich farms in the Western Cape Province, South Africa. Preventive Veterinary Medicine, 86: 139-152. In a 2005 serological survey, carried out in response to an outbreak of H5N2 avian influenza (AI) in ostriches in the Eastern Cape Province, 16.3% of ostrich farms in the Western Cape Province of South Africa were found to be seropositive to H5 AI virus. We subsequently carried out a questionnaire-based census survey on all available registered Western Cape ostrich farms that still existed at the end of 2005 (367 farms, of which 82 were seropositive), in order to identify risk factors associated with farm-level seropositivity. A farm was classified as seropositive for H5 AI virus if one or more birds had tested positive (haemagglutination inhibition titre >1:16) in the 2005 survey, which had been designed to detect a minimum within-group seroprevalence of 10%. For each farm, risk factor information was collected using a questionnaire administered during a face-to-face interview with each farm owner or manager. Information was obtained on the ostrich population, movements of birds, environmental factors, management practices, and frequency of contact between ostriches and various wild bird species. Multiple logistic regression models were developed for the whole Western Cape Province and also for the two largest ostrich farming regions, "Klein Karoo" and "Southern Cape". Seroprevalence differed between regions, being highest in the Klein Karoo (31.6%). In all three models, increased risk of farm-level H5 AI virus seropositivity was associated with increasing numbers of ostriches, excluding chicks, present on the farm. Increased risk of seropositivity was associated with reduced frequency of cleaning of feed troughs (1 × /week), both overall (odds ratio (OR)=4.5; 95% confidence interval (CI): 1.5, 13.3) and in the Southern Cape (OR=53.6; 95% CI: 3.3, 864), and with failure to clean and disinfect transport vehicles, both overall (OR=2.3; 95% CI: 1.1, 4.8) and in the Klein Karoo (OR=2.6; 95% CI: 1.1, 6.5). Increased risk of seropositivity was also associated with increasing frequency of contact of ostriches with certain wild bird species: overall with white storks (Ciconia ciconia), in the Southern Cape with gulls (Larus spp.), and in the Klein Karoo with Egyptian geese (Alopochen aegyptiaca).

WANG, J.X. & PENG, K.M. 2008. Developmental morphology of the small intestine of African ostrich chicks. Poultry Science, 87: 2629-2635. The objective of this study was to investigate the morphological development of the small intestine of African ostrich chicks and to examine the changes in the number of goblet cells therein by observing the gross anatomy and performing histochemistry and morphometry. The BW; length, height, and width of the villi; muscle thickness; depth of the crypts; and number of goblet cells in the intestinal villi and crypts were measured on neonatal d 1, 45, 90, and 334. Our results revealed that the weights of the duodenum, jejunum, and ileum (relative to the BW) peaked on d 90, 45, and 45, respectively, and tended to decline thereafter. The villus height and width and muscle thickness in the small intestine were positively correlated with the age of the birds. The ratio of the villus height to the crypt depth differed among the segments of the small intestine and at the different time points. The number of goblet cells in the intestinal villi and crypts increased rapidly up to postnatal d 45 and then decreased rapidly between d 45 and 90. The number of goblet cells in the villi was greatest in the jejunum on d 1 and in the ileum on d 45, whereas that in the crypt was greatest in the ileum on d 1 and 90 and in the duodenum on d 45. These results suggest that the small intestine develops gradually from postnatal d 1 to 90 and that the period up to postnatal d 45 is marked by significant developmental changes in the parameters reflective of the digestive capacity, such

as the weight, length, and surface area of the intestine and the number of goblet cells. Therefore, in reared African ostrich chicks, feed management should be enhanced between postnatal d 1 and 45.

WANG, J.X., PENG, K.M., LIU, H.Z.H., SONG, H., CHEN, X. & LIU, M. 2009. Distribution and developmental changes in ghrelin-immunopositive cells in the gastrointestinal tract of African ostrich chicks. Regulatory Peptides, 154: 97-101. Ghrelin, the endogenous ligand for the growth hormone secretagogue receptor (GHS-R), has been found in the gastrointestinal tract of many vertebrates, but little is known about its distribution in the gastrointestinal tract of African ostrich chicks. In the present study, the distribution, morphological characteristics, and developmental changes of ghrelin-producing cells in the gastrointestinal tract of African ostrich chicks were investigated using immunohistochemistry. Ghrelin-immunopositive (ghrelin-ip) cells were found to be localized in the mucous membrane of the entire gastrointestinal tract, but not in the myenteric plexus. The greatest number of ghrelin-ip cells was found in the proventriculus, and the ghrelin-ip cell density gradually decreased from the proventriculus to the rectum. Interestingly, from postnatal day 1 to day 45 in the proventriculus, and from postnatal day 1 to day 90 in the gizzard and small intestine, there was a steady increase in the number of ghrelin-ip cells. By day 45 in the proventriculus and day 90 in the gizzard and small intestine, the number of cells reached a plateau and remained steady. These results clearly demonstrate that ghrelin-ip cells exist and the number of ghrelin-ip cells increases with age in the African ostrich gastrointestinal tract from postnatal day 1 to day 90; ghrelin may be involved in gastrointestinal tract development.

WANG, J., PENG, K., DU, A., TANG, L., WEI, L., JIN, E., WANG, Y., LI, S. & SONG, H. 2007. Histological structure of the digestive tract in African ostrich chicks. Chinese Journal of Zoology, 42: 131-135. The histological structure of digestive tracts from six 50-day old African Ostrich Chicks( Struthio camelus) were studied by paraffin sectioning and haematoxylin-eosine (H.E) staining. It is indicated that African Ostrich's digestive tract is composed of four conventional layers. The grossus plica, developed muscularis, and developed esophageal glands exist in the esophagus. Ingluvies is not observed. The glandular glands in glandular stomach consist of simple tubular glands in the lamina propria and compound tubular glands in the submucosa. The muscularis mucosa of the muscular stomach is obvious, and it is composed of internal-longitudinal and external-ring smooth muscles. The villi in small intestine are long and branchy, but they contain no central chyle vessels. There are developed intestinal gland and many aggregated lymphoid nodule in the lamina proper of the duodenum. There is no duodenal gland in the submucosa. From duodenum to ileum, intestinal villi have more evident confluences and branches; the intestinal villi in jejumum are crook and "S" shaped, and the number of aggregated lymphoid nodule gradually decreases. African ostrich has a pair of developed cecum and very developed colon, where the epithelium mucosae is stratified columnar epithelium with many goblet cells and where there are mucosa plica and short and developed villi. These features of the digestive tract are possibly related food habit, and determine the fact that African Ostrich has a strong ability to digest and absorb food

WAUGH, E.E., AGANGA, A.A., SEABO, D., OMPHILE, U.J. & TSOPITO, C.M. 2006. Growth rate and feed conversion rate of ostriches fed ration with or without grit in Botswana. International Journal of Poultry Science, 5: 470-473. The objectives of this study were to investigate the effect of grit on the growth rate, feed intake and feed conversion efficiency of ostrich chicks which were given grit and those not provided with grit. Six female and four male ostrich chicks aged nine (9) weeks were randomly assigned into two feeding groups using completely randomized experimental design. In each feeding group there were five young birds raised in a pen. All the young birds were fed with ostrich grower's mash and water ad libitum. One group had access to grit during the study while other group did not. At week 18 weeks feed given to both groups of young ostriches and leftover were weighed on daily basis. Body weights were recorded on a monthly basis throughout the study. Average daily feed intake and average daily weight gain were determined. Feed conversion efficiency was calculated using average daily feed intake and

average daily weight gain. The data was analysed using Student-t analysis at P<0.05. Average daily weight gain was higher (0.38±0.03 kg/d) in ostrich chicks that had access to grit as compared to ostrich chicks (0.37±0.04 kg/d) that had no access to grit. Average daily feed (dry matter) intake was higher (1.95 ±0.27 kg/d) in ostriches that had no access to grit than those (1.94±0.20 kg/d) access to grit. Feed conversion efficiency of ostriches with access to grit was higher (5.11±0.93) than those (5.27±1.30) without access to grit. Giving grit to young ostriches should be recommended both to improve growth rate and feed conversion efficiency and to reduce feed intake.

WINGS, O. 2003. Observations on the release of gastroliths from ostrich chick carcasses in terrestrial and aquatic environments. Journal of Taphonomy, 1: 97-103.

WUSTINGER, J., JASKO, D., DROZDZ, D., BASINSKA, M. & POSPIESZNY, N. 2006. Muscles of thoracic limb of African ostrich (Struthio camelus L.). Electronic Journal of Polish Agricultural Universities, 9: //www.ejau.mea./oume9/ssue2/art-03.htm. The objective of the study was to analyze the wing musculature of the African ostrich. The investigation was conducted on four three-day old chicks of the ostrich. The muscles were characterized by poor development due to a very young age, and no flight abilities. The basic muscle units were described, the measurements of their length and width were taken and their mutual relation was calculated. All values were collected in a table. The photographic documentation was also prepared.

YAN, W., KEMEI, P., JIANLI, L., HUI, S., SHENGHE, L., LAN, W. & JIAXIANG, W. 2008. Ultrastructure and melatonin 1a receptor distribution in the ovaries of African ostrich chicks. Cytotechnology, 56: 187-195. Healthy 90-day-old ostrich chicks were used in the present study. The ultrastructure and melatonin 1a receptor (MT1) distribution in the ovaries of ostrich chicks was observed by transmission electron microscope and light microscope. The results showed that the ostrich chick ovary contained primordial follicles, primary follicles and secondary follicles, but no mature follicles. There are some unique ultrastructural characteristics observed in the secondary follicle, such as the cortical granule, which was located in cytoplasm beside the nucleus and appeared first in the oocyte. The zona radiata appeared in the secondary follicle, and there was an obvious vitelline membrane. There were intraovarian rete, connecting rete, and extraovarian rete in the ovaries of ostrich chicks. This is the first study that provides immunohistochemical evidence for the localization of the melatonin MT1 in the ostrich chick ovary. The germinal epithelium, follicular cell layer of every grade of follicle, cytoplasm of the oocyte and interstitial cells all expressed MT1. The expression of positive immunoreactivity materials was the strongest in the follicular cell layer of the primordial follicle and germinal epithelium, was weaker in the follicular cell layer of the primary follicle and secondary follicle, and was weakest in the oocytes of all grades of follicle. In addition, the extraovarian rete displayed strong positive expression of MT1, while there was no positive expression in the intraovarian rete or connecting rete. The positive expression of MT1 immunoreactivity in the ovary was very strong, implying that the ovary is an important organ for synthesizing MT1.