Effect of different stocking densities on performance, egg quality characteristics and welfare status of two commercial layer genotypes kept in conventional and enriched cages

This study was carried out to determine the effects of two different cage systems (enriched and conventional) and low and high densities on performance, egg quality and behavioral characteristics of two native (Atak-S) and foreign (Lohman) Eggs were analysed interms of internal (white height, yellow index, haugh unit) and external quality characteristics (shape index, breaking strenght, shell weight, shell thickness, total number of microorganisms and enterobacteria on shell) at 50 %, peak and 40-60 weeks yield periods. In study, welfare status of birds raised at different densities at enriched and coventional batery cage systems were also examined. In hens, welfare parameters (canibalism, inaction behaviour, injuries, feathering score) and characteristics of tibia bone (breaking strenght, ash content, bone diameter, bone length) were determined. laying hens.. The laying hens were placed in cages with 3 replications according to 2x2x2 factorial experiment desing. Hens were given pre-lay diet from 18 up to 22 weeks and then fed a laying hen diet. ighting regime was 16 L:8 D with the intensity of 15 lx/m2 during the egg production period. In order to determine the egg quality characteristics, a total of 240 eggs, (30 eggs/group) were analyzed every 4 weeks. Body weight of hens were determined atsexual maturity age (5% egg yield), peak egg yield and at the end of the experiment. Egg production, egg weight, daily feed intake, total feed intake and feed conversion ratio (FCR) were determined between 18-25, 25-44, 45-76 and 18-76 weeks. The results indicated that genotype significantly affected end-of-experiment body weight at 76 weekand peak at egg production age periods. It was determined that Lohmann genotype had higher of egg production and egg weight than Atak-S genotype during period of 18-76 weeks. The effects of genotype and cage system on egg production were found to be significant. It was seen that hens consumed more feed in enriched cages and had better feed conversion ratio at low density. Lohman genotype was found to have higher egg quality characteristics. The total number of microorganisms in egg shells was found to be higher in the enriched cage system. The cage system was appeared to affect only the breaking strenght of the egg. The tibia breaking strenght was found to be lower in Lohman genotype and at high stocking density. The effects of genotype, cage and stocking density were found to be significant on fathering score determined at hens in peak period (25 week) and at the end of experiment (76 week). As a result, it was clearly seen that as cage system and stocking density affected the welfare levels of the chickens, genotype was influence on egg production and egg quality also.