Hatchability prediction in chickens using some external egg quality traits.
The aim of this study was to predict hatchability using external egg quality traits. Seven hundred and twenty eggs were collected from inbred populations of three strains of layer-type chickens comprising of two exotic strains: Black Olympia (BO), H and N brown nick (H and N) and the Nigerian Local Chicken (NLC) at 40 weeks of age. The external egg quality traits measured include Egg Weight (EW), Egg Shape Index (ESI), Shell Weight (SW) and Shell Thickness (ST). Highly significant variations existed between the two exotic strains (BO and H and N) and the NLC in all traits expect actual hatchability. Eggs from BO and H and N were 27.76 and 28.34% heavier than those from the NLC (p<0.01). Actual hatchability percentage ranged between 87.73-88.24%. All egg quality traits studied were negatively correlated with hatchability (EW-0.27, ESI-0.38, SW-0.24 and ST-0.68). The correlation between ESI, ST and hatchability were significant (p<0.01). The multiple linear regression analysis revealed that all the traits except EW had significant (p<0.01) linear effect on hatchability with a coefficient of determination (R2) of 0.698. The estimated hatchability prediction model was =124.169-0.007EW-0.358ESI+0.639SW-37.283ST. The high R2 obtained in this study indicates that the variables employed in predicting the model were adequate and therefore suggests the likelihood that the various external egg quality traits influenced hatchability and could be interpreted in an integrated manner, rather than from a mutually exclusive individual basis.