HATCHABILITY
Ar A, Gefen E Further improving hatchability in artificial incubation of ostrich eggs.
Proceedings of the Second International Scientific Ratite Congress, Oudtshoorn, South Africa, 21-25
September 1998, 1998, 141-147. Oudtshoorn,
INCUBATION, EGGS, TEMPERATURE, STORAGE, EMBRYO, METABOLISM.
Some fundamental structural and physiological data and management principles are described that could be used for the improvement of artificial incubators and the design of hatcheries. The paper describes: (1) egg storage time in relation to hatchability; (2) embryonic development and the assessment of embryonic age in comparison to fowls; (3) embryonic energy metabolism in relation to incubation temperature, incubation duration and embryonic growth. The paper also presents new data, obtained by the authors, on the influence of storage time on hatchability.
Badley A Boosting ostrich productivity through better egg hatchability..
RIRDC Research Paper Rural Industries Research and Development Corporation Kingston., 17,
1998., 174 pp.
BREEDING, REPRODUCTION, EGG-SHELLS, EGGS, STORAGE, INCUBATION.
This publication describes in detail 13 studies carried out in Australia between August 1993 and
December 1996, with much of the work being done on ostrich farms in southeastern Queensland. One of the studies was a comprehensive review of the world literature on ostrich reproduction, and this has been accepted for publication in Poultry and Avian Biology Reviews. The other studies dealt with (1) ostrich breeding and management in Australia, (2) hatching failure, (3) egg shell ultrastructure, (4) egg storage, (5) natural nesting and incubation, (6) candling of eggs, (7) preparation of a candling chart,
(8) egg turning, (9) egg weight loss during storage and incubation, (10) incubation temperature, (11) gas exchange of eggs, and (12) a study with fowls to investigate growth on 3 commercial ostrich diets, following the suggestion that widespread deaths in ostrich chicks in 1995 may have been related to diet.
Badley A Maximising the hatchability of ostrich eggs by improved candling efficiency during artificial incubation.
Proceedings of the 5th Australian Ostrich Association Conference, 1996, 71-79.
CANDLING, ALBUMEN, EMBRYO, DEVELOPMENT, INCUBATION, HATCHING.
Some findings of this study: Fertility in some eggs can be detected as early as day 3 of incubation.
Fertility can be more easily detected when the egg is candled from the air cell end rather than with the light source under the egg. An early dead embryonated egg can be detected. Normal development of a late embryo can be checked Candling can show when an embryo is malpositioned as it prepares to hatch
Deeming D C Egg size and hatchability in ostriches.
Ostrich News, 7(73), 1994, 52-54.
EGGS.
Deeming D C Factors affecting hatchability during commercial incubation of ostrich (Struthio camelus) eggs..
British Poultry Science, 36(1), 1995, 51-65.
INCUBATION, ENVIRONMENT, TEMPERATURE, EMBRYO, WEIGHT, EGGS,
CONTAMINATION, FERTILITY.
1. A batch of 320 ostrich eggs from 9 different farms in Zimbabwe were incubated in a single stage operation and the fate of each was recorded. 2. Hatchability was only 37.2% and the result of high rates of infertility and contamination (22.2% and 22.8% respectively); it varied between eggs from different farms. 3. Embryonic mortality was high at the start and end of incubation, a pattern similar to that of other domestic birds. 4. Mortality of late stage embryos was related to percentage water loss and mass specific water vapour conductance of the shell, with extremes of the ranges causing the highest mortality. 5. Microbial contamination of the eggs was a significant problem and varied in eggs from different farms indicating that more attention is needed in both breeder bird and nest management.
Deeming D C Factors affecting hatchability of ostrich chicks.
Proceedings of the 9th European Poultry Conference, Glasgow: Satellite Symposium on Gamebirds and Waterfowl, 1994, 1994, 38-41.
HATCHING, INCUBATION PARAMETERS, MALPOSITIONING.

The unusual hatching sequence of the ostrich means that it has malpositions peculiar to it and should not be compared to the fowl
Deeming D C Factors affecting hatchability of ostrich eggs.
Proceedings of the 9th European Poultry Conference, Glasgow: Satellite Symposium on Gamebirds and Waterfowl, 1994, 1994, 38-41.
HATCHING.
Gonzalez A, Satterlee D G, Moharer F, Cadd G G Factors affecting ostrich egg hatchability..
Poultry Science, 78(9), 1999, 1257-1262.
CHICKS, EGG WEIGHT, EGGS, INCUBATION, LOSSES, EGG-SHELLS.
Eggs were collected from 4 trios of ostriches over a 5-month period (March to August 1997) near the middle of the breeding season. Eggs were stored for _5 days or >5 days before incubation and eggshell porosity and thickness, egg weight loss during incubation and hatchability were recorded.
Eggs were grouped as having low, intermediate or high eggshell porosity and low, intermediate or high shell thickness. Mean weight loss was higher (P<0.05) in eggs of the high-porosity group than for those with low or intermediate porosity. Mean hatchability was also higher (>25%; P<0.10) in eggs with high porosity than in those with low porosity. Eggs from the intermediate-porosity group had intermediate hatchability. Numbers of large pores were positively correlated with egg weight loss (r2
= 0.64; P<0.0001) and hatchability (r2 = 0.25; P<0.03). Inverse relationships existed between eggshell thickness and egg weight loss and hatchability (P<0.05). Although shell thickness was unaffected by egg size, higher porosity (P<0.10), weight loss (P<0.05) and hatchability (P<0.10) were found in medium-sized eggs compared with small or large eggs. Chick weight was associated with egg size
(P<0.05). Neither weight loss nor hatchability was affected by length of preincubation egg storage.
Musara C, Chidhumo P, Muronzi N A retrospective analysis of water balance and hatchability in artificially incubated ostrich (Struthio camelus) eggs.
Zimbabwe Veterinary Journal, 30(3-4), 1999, 75-84.
EGGS, INCUBATION, WATER BALANCE, DEHYDRATION, HUMIDITY, MORTALITY,
PHYSIOLOGY.
A retrospective analysis of water balance in ostrich eggs was conducted to investigate the influence of hydration status on hatchability with the objective of reducing embryonic mortality associated with abnormal hydration states. Water loss in 228 eggs that hatched successfully and 64 eggs with chicks that had died near full term was calculated from hatchery records. Dead chicks were autopsied for evaluation of their hydration status. Results indicated that under the same relative humidity, embryonic deaths arise from both excessive water loss and excessive water retention. This was attributed to a 24% coefficient of variation in the water vapour conductance of individual egg shells.
Whereas deaths resulting from excessive water loss can be prevented by adjusting the relative humidity, deaths associated with excessive water retention cannot be similarly eliminated owing to concurrent respiratory insufficiency. It is therefore prudent to select relative humidity levels that minimize embryonic losses from dehydration.
Szabo-Willin E, Tavas A (Long-time storage effect of the ostrich egg on the hatchability.) A strucctojas tarolasi idejenek hatasa a keltethetosegre.
Future prospects for Hungarian animal production (challenges and opportunities). Scientific conference at the Hungarian Academy of Sciences, 24 November 1999 [programme leader, Kovacs,
F.]. Allattenyesztes-es-Takarmanyozas., 48(6), 1999, 858-860.
EGG WEIGHT, HATCHING, STORAGE, INCUBATION.
462 ostrich eggs were stored for 1-9 days before incubation. Egg weight was recorded during storage.
Loss in egg weight increased from 0.08% with 1 days storage to 0.8% with 9 days storage, and was lowest in the summer. 'Hatching damage' over the 8 days storage was about 25%. Hatching occured after 41-44 days incubation (43-44 days after 8 days storage).
Hungarian.
Wilson H R, Eldred A R, Wilcox C J Storage time and ostrich egg hatchability.
Journal of Applied Poultry Research, 6(2), 1997, 216-220.
STORAGE, EGGS.
Eight local ostrich producers collected eggs and stored them for up to 15 days at 55°-60°F. The eggs were then incubated in the University of Florida hatchery. Eggs from different farms showed significant differences in fertility and hatchability as a percentage of fertile eggs. Hatchability declined

linearly with storage time, although storage for up to 7 days had relatively little effect on hatchability.
Hatchability also declined linearly with successive sets, possibly reflecting an effect of season. Egg weight loss to day 38 of incubation averaged 13.2% for eggs that hatched. Chick weight at hatching averaged 63.6% of initial egg weight, which is similar to published values for most avian species.
Chicks lost body weight at a rate of 1.35 g/h if not removed immediately from the incubator after hatching. After hatching, oedematous chicks were more alert and mobile if allowed to dry in the incubator