> Effects of Stocking Density and Genotype on the Growth Performance of Male and Female Broiler Chickens

摘要

carcass characteristics , since the recommended densities are based on researches in temperate environments. Therefore, the interaction effects of genotype, sex and stocking density on growth performance and > carcass characteristics were investigated. Materials and Methods: Male and female Ross 308 and Cobb Avian 48 broilers were reared at stocking densities of 30, 35 and 40 kg BW m -2 over 42 days. Data were analyzed by a three-way ANOVA for a 3×2×2 factorial using the GLM procedure of Minitab 17. Results: During the entire period, genotype had no effect (p>0.05) on any growth performance traits. While, males consumed 8.5% more (p<0.01) feed, gained 11.5% more (p<0.01) body weight and were 10.9% heavier (p<0.01) at slaughter (day 42) than females. For stocking density, broilers reared at 30 kg BW m -2 consumed 9.0 and 12.8% more (p<0.01) feed, gained 7.4 and 9.4% more (p<0.01) body weight and were 6.8 and 8.7% heavier (p<0.01) at slaughter than those raised at 35 and 40 kg BW m -2 , respectively. Except the reduction (p<0.05) in breast percentage weights with increasing stocking density, neither genotype, sex nor stocking density influenced (p>0.05) percentage weights of carcass parts. There were also stocking density×sex interaction effects (p<0.05) on feed consumption, genotype×stocking density interaction effects (p<0.05) on the relative weights of the wing and abdominal fat and genotype×sex interaction effects on 42 days body weight (p<0.01) and relative weight of the wing (p<0.05). Conclusion: The results showed that male Cobb Avian 48 raise at stocking density of 30 kg BW m -2 performed better in the sub-tropics specifically in winter.]]>