Genetic and Sex Differences in Carcass Traits of Nigerian Indigenous Chickens

Genetic and sex differences or variation in carcass characteristic and slaughter yield were studied using a total of 150 intensively reared and clinically normal chickens consisted of 50 each of normal feather, naked neck and frizzled matured chickens genotypes. The result showed that genotype as well as sex have significant effect (P < 0.05) on carcass characteristics and slaughter yield at twenty weeks old. The slaughter weight means values ranged from 1693.00±71.43g to 2084.00±108.43g in normal-feathered to naked-neck chicken. The slaughter weight, carcass weight and dressing percentage were better in the naked neck chicken than other genetic groups. Moreover, male chickens showed significant (P < 0.05) and higher slaughter weights, carcass weight, dressing percentage than females across all genotypes. Correlation coefficients (r) among carcass traits were all positive and very highly significant (P < 0.01) and ranged from 0.14 which was not significant (P > 0.05) between shank and wing to 0.99 (P < 0.01) between WAB and SLWT, WAD and WAB, Head and WAB, Head and WAD and Breast and DS. Coefficient between carcass traits and organs were also significant (P < 0.01) with r values ranging from 0.00 between kidney and all other cut parts to 0.89 between slaughter weight and abdominal fat. It could therefore be concluded that variations in the genetic make-up and sexual dimorphism in the chickens accounted for the observed differences in carcass characteristic. The present result on carcass characteristic of the chicken genotypes could serve as a base line data, which could be exploited in the improvement of the local stock. However, the application of molecular tools will give clearer understanding and better application of these differences.