On July 4, 2002 at a Polish ostrich farm, Ożarów, a case of ostrich (Struthio camelus) twins developing from a double-yolked egg was reported. On the day of laying the weight of egg was 2221 g, whereas its shape index was 73.7, resembling the chicken egg. On day 43 of incubation the egg was opened.Each embryo was fully formed with complete feathers. Both embryos died in the last stage of incubation,on day 33 or 34. The embryos were lying with their ventral surfaces opposed with the yolk sacs positioned between them. The embryos weighed 245.2 g (twin 1) and 259.3 g (twin 2). This case report is unique and it is hoped that it will provide a valuable contribution to the current literature on ostrich eggs.
The cholesterol content differed (P<0.05) between breast (49.5 mg/100 g) and back (74.3 mg/100 g) fat. Differences (P<0.05) in individual fatty acids were found especially for arachidonic acid (20:4).High contents of 18:2, 18:3 and 20:4 from both depots suggest, that ostrich fat could be a source of essential fatty acids in human and animal diets. The influence of various factors and especially feeding regimen on quantity and quality of ostrich fat should further be investigated.
Culled breeding ostriches weighing 130-160 kg yield about 25 kg fat tissue that could possibly be used for supplementing human and animal diet. Cholesterol content of breast fat – 80 mg/100 g tissue – from the breeding ostrich females (n = 6) culled and slaughtered at the age of five years appeared similar to that reported of beef and lamb adipose tissue. In a sum of 17 fatty acids (FA) determined, the mono- and polyunsaturated FA accounted for 37.51 and 38.84%, respectively. The ratio polyunsaturated/saturated FA in breast fat of culled breeding ostrich females appeared higher than reported for other avian species.It is concluded that fat from culled breeding ostriches can be used as an additive to human or animal diet, thus allowing the farmer to gain more from ostrich production. Further research is needed on composition and properties of adipose tissue of ostriches, including slaughter, as well as breeding birds culled at different ages.