Effect of egg weight on ostrich (Struthio camelus) chick weight and growth

Abstract

The aim of this paper is to evaluate the effects of the age of ostriches and month of laying on egg production and chick growth. On a small ostrich farm egg production, egg incubation and chick growth from hatching to 56 days of age were recorded from 2000, when the breeders were 5 years old, until 2002. Ostriches were kept in groups and fed commercial feed. In all, 568 eggs were laid and weighed at laying and during incubation (at 15th and 30th day of incubation), while 353 chicks were weighed at hatching, 7, 14, 28 and 56 days of age.The female’s productivity was calculated assuming a laying of 3.5 eggs per week and ranged between 45% and 48%. The fertility was around 70% with a peak of 74% recorded in 2001. The hatchability of all eggs was higher than 62% with a peak of 72% in 2001, while the hatchability of fertile eggs was higher than 90%. In each year the number of eggs laid increased from March to July, productivity showed a positive trend from May to June, while the fertility and hatchability of all eggs, as well as fertile eggs, was unaffected by year and month. As the hens aged, the egg mass grew constantly with an increase of about 8%. During the first 30 days of incubation the egg weight decreased with the percentages of weight loss around 10.0%. At hatching, the weight of chick ranged between 765 g and 847 g, respectively, in 2000 and 2002. Egg weight influenced the hatching weight showing a linear relationship (R2=0.84). The effect of egg weight on the chick weight decreased as the chick grew. At 56 days of age, only the effect of year is significant. The month of laying did not demonstrate any effect on chicken weight.