The effect of different combinations of dietary energy and protein on the composition of ostrich eggs

Abstract Nutrition of breeding female birds can influence egg quality and is therefore extremely important for the development of the embryo and the successful hatching of a high quality chick. We investigated the effect of combining different levels of dietary energy and protein, with accompanied amino acid levels, in the diets of female ostriches on the composition of their eggs. Ninety pairs of breeding ostriches were divided randomly into nine groups of 10 pairs per group in a factorial design with three energy and three protein levels. The groups were fed diets with levels of 7.5, 8.5 and 9.5 MJ metabolisable energy/kg, each combined with each one of three protein levels 105, 120 and 135 g/kg respectively. Fresh eggs were collected from each group at the end of the breeding season and the albumen and yolk separated and analysed for protein and lipid content and for amino acid and mineral composition. No significant interaction between energy and protein levels occurred. Despite some differences in egg composition and amino acid concentrations, different dietary energy and protein levels for the most part had little or no effect on the composition of ostrich eggs.