Abstract
This experiment was conducted to evaluate the correlations between external and internal egg quality traits of Isa Brown hens raised in the Tropics. A total of 90 eggs were randomly sampled within the period of nine weeks for external and internal egg quality measurement at the Poultry unit of Akwa Ibom State University, Akwa Ibom State Nigeria. The external egg qualities studied were egg weight, egg length, egg width, and shell thickness, while internal egg qualities were albumen height, albumen width, albumen ratio, albumen length, yolk width, yolk ratio, yolk weight, yolk height and haugh unit. All external and internal egg trait data collected were subjected to descriptive statistics (means, standard deviation, standard error and coefficient of variation). The correlations amongst external and internal egg parameters as well as correlations between internal and external traits were determined. Simple linear and multiple regressions were employed to predict egg weight and internal egg traits. Results on the correlation amongst external egg quality traits showed that egg weight had a very high positive significant (P < 001) correlation with egg width (0.936) and shell weight (0.973). A highly significant (P <001) negative correlation (-0.997) was observed between egg width and shell ratio. Result on the correlation amongst internal parameters showed that the relationship between Albumen height with Albumen width (-0.29), Albumen ratio (-0.19), yolk ratio (-0.27) and Haugh unit (-0.99) were negative. The results also indicated that combination of egg width and egg length gave the best fit for egg weight and other internal egg parameters. This implies that any improvement made on egg length and egg width can positively influence internal egg qualities. Hence, it was concluded that egg external quality traits (egg length and egg width) could be used as selection criteria to improve internal egg quality traits.