Effect of Yolk Hormones and Egg Weight on the Sex of Hatch Chicks, Hatchability and Embryonic Mortality of Japanese Quail

This study was conducted to investigate the effect of yolk hormones and egg weight on the sex of hatch chick, hatchability traits, and embryonic mortality. Four hundred and fifty eggs were used in this study. The eggs were divided according to their weight into three groups A: 8-9 g, B: 10-11 g and C: 12-13 g. Each group had 150 eggs.Yolk testosterone and estradiol concentrations were assessed after 10 days of Incubation. The results significantly indicated more testosterone in small eggs, whereas concentrations of all yolk estradiol increased in large eggs. The results indicated a significant increase in males’ rate hatching from small eggs, whereas highest females’ rate were recorded in large eggs.There was a significant difference between groups in hatchability of fertile eggs and hatch weight of incubated eggs. The highest hatchability of fertile eggs and hatching weights were recorded in the C group, whereas highest embryonic mortality was recorded in A group. We can conclude that, the concentration of yolk testosterone and males’ rate were increased in small eggs whereas concentrations of yolk estradiol and females’ rate were increased in large eggs. In addition, the largesized eggs of Japanese quail are suitable for incubation for better hatchability, lower embryonic mortality and best chick’s weight at hatch as compared to small sized eggs.