Evaluation of Egg Quality Traits of Local Chickens in the Humid Tropical Environment of Umudike, Southeast Nigeria
Four hundred and thirty six (436) eggs laid by seven genotypes of local chickens within 56 days were used to evaluate egg quality traits. The genotypes evaluated were the homozygous naked neck (Na/Na) and frizzle (F/F), heterozygous naked neck (Na/na) and frizzle (F/na), reciprocal crosses between naked neck and frizzle (Na/F, F/Na) and homozygous normal feathered (na/na) chicken. Results showed that genotypes differed significantly (p<0.05) in all the external egg quality traits except for eggshell thickness (ST) and some internal egg quality traits. The F/F, Na/Na and Na/F genotype had the highest values for egg weight (EWT), egg length (EL), egg shape index (EI), yolk weight (YWT), yolk height (YH), yolk width (YW) and yolk index (YI). The highest EL and EI values were recorded for F/F and F/Na genotypes respectively whereas the highest YWT values were recorded for F/F, Na/F and Na/Na genotypes. The F/Na and Na/Na ranked highest in YH, while the F/F and Na/F genotypes ranked highest in YW. The YI values were better in eggs produced by the F/Na and Na/Na genotypes. The genotypes did not differ significantly (p>0.05) in albumen weight, albumen height and Haugh unit. However, higher values were recorded for Na/F genotype. It was concluded that both naked neck and frizzle homozygotes and their reciprocal crosses were superior in egg quality traits than either the normal genotype or genotypes heterozygous for normal feathering.