Association of rate-of-feathering genotypes in broilers with production and carcass composition traits. 2. Effect of genotypes and diet on processing traits and lipid deposition

Five rate-of-feathering genotypes: K/K, K/k+, and k+/k+ in male and K/W and k+/W in female broilers were produced from matings of grandparent stocks of a common genetic background. Genotypes were compared for differences in processing characteristics and lipid deposition using isocaloric high and low protein diets from 28 to 52 days. The two female genotypes reared on the same diet did not differ on measures of plant weights, eviscerated carcass weights, breast weights, and abdominal fat pad weights. Significant differences were observed among the male genotypes reared on the same diet in plant weights, eviscerated carcass weights, and breast weights. All genotypes reared on the high protein diet had significantly increased plant weights, eviscerated carcass weights, and breast weights and significantly decreased abdominal fat pad weights and percentage carcass lipid.