Study of Some Productive Performance and Egg quality Traits in Two Commercial Layer Strains.

Abstract

This experiment was conducted to evaluate genetic differences of productive performance and egg quality traits in two commercial layer strains of chickens under prevailing Egyptian environmental conditions. Results demonstrated that brown strain had significantly heavier body weight compared to the white ones. Body weight increased gradually as layers age increased. The strain had insignificant effect on egg number, while layer age had significant effect on this trait. The brown layer hens produced significantly heavier egg weight compared to the white ones. Egg mass of brown eggs were heavier than white eggs. The present results showed that the brown layers significantly consumed more feed compared to the white ones. W-36 layers strain had better feed conversion ratio compared to brown layers strain. Concerning age effect, also feed conversion ratio increases with advancing of layers age, consequently feed efficiency decreases. The brown eggs recorded significantly higher in all eggshell quality traits compared to the white eggs. The mean performance of the eggshell quality traits such as (egg shape index, eggshell breaking strength, shell percentage and shell thickness) declined with advancing layers age with the exception of eggshell weight which increased with layers age. Regarding internal egg quality, it could be noticed that albumen weight and percentage of the brown eggs was significantly higher than that recorded for white ones. While, we found that white eggs had significantly higher Haugh unit compared to the brown ones. Generally, the albumen weight increases with advancing of layers ages. Inversely, albumen as a percentage of total egg weight and Haugh units decreased as layers age increased. The yolk weight, yolk percentage and yolk index increases with advancing of layers ages.