Comparison of laying performance, egg quality and bone characteristics of commercial and tiirk laying hen genotypes kept in a free-range system [1]

Abstract

This study was designed to compare of laying performance, egg quality and bone characteristics of commercial and Tiirk laying hen genotypes kept in free-range system. A total of 720 laying hens (Atabey, Lohmann White, Atak-S, Lohmann Brown; n=180 hens/genotype) were used in the experiment. Production performance was determined as the mean of egg production, egg weight, and FCR value between 54 and 66 weeks of age. Egg quality parameters and bone characteristics of tibia and femur were measured at 66 weeks of age. The mean value of egg production was found to be higher in Lohmann Brown and Lohmann White genotypes compared to Atak-S and Atabey genotypes between 54 and 66 weeks of age (P<0.01). The brown eggs obtained from (Lohmann Brown, Atak-S) genotypes tended to be heavier than the white hen genotypes (Lohmann White, Atabey). The lowest mean value of FCR was observed in Lohmann White hens ranged from during the experimental period. The Lohmann Brown and Atak-S eggs obtained from (3.350 g/cm2 and 3.300 g/cm2) had a stronger shell strength compared to the Lohmann White and Atabey (2.847 g/cm2 and 2.910 g/cm2, P<0.01). The breaking strength of tibia was found to be higher in brown hens (366.0 N and 381.2 N) than white hens (267.0 N and 322.2 N) (P<0.01). These findings related to different genotypes could be instructive for arranging new management rules and nutritional advice for stronger eggshell and bone strength of hens in free range system.