Poultry Studies
2020, Vol 17, Num, 2 (Pages: 063-074)
The Effects of End of the Growth Period Live Weights on Pure Lines Egg Yield Used in Brown Egg Production
2 Animal Science Departmant, Faculty of Agriculture, Ondokuz Mayıs University, 55139 Atakum, Samsun, Turkey DOI : 10.34233/jpr.834850 - This study was carried out in order to reveal the effects of live weight at the end of the rearing period on yield characteristics during the laying period in RIR-I and BAR-I pure lines, which are the parents of ATAK-S chickens developed for use in brown egg production. Significant differences were found between genotypes and between different body weight groups in terms of 16-week age, 50% yield age, 40-week live weight determination of BAR-I and RIR-I genotypes, and mortality rate between 16-40 weeks of age. First spawning age, 50% yield age and peak yield age reached earlier in the heavy group of the BAR-I genotype. Those in the light group of RIR-I genotype reached these yield levels at the latest. It was revealed that the BAR-I genotype was higher than the RIR-I genotype in terms of egg production hen-day (piece) and chicken-poultry (piece) values, but the RIR-I genotype reached a higher yield value in terms of hatching egg yield (pieces). In general, the difference between the lines was found to be significant in terms of internal and external egg quality characteristics. Differences between genotypes in feather scores were found to be significant and a decrease in feather score was observed depending on age. In terms of FPD values, it was observed that the differences between genotypes were not significant, but FPD damages increased as age and live weight increased. As a result of the research, the benefit of classifying RIR-I and BAR-I pure lines according to body weight at the end of the rearing period has been revealed, especially in terms of hatching egg production. Keywords : Brown laying hens Pure lines Body weights Performance Egg quality
