Phenotypic Correlations Between Some External and Internal Egg Quality Traits in the Exotic Isa Brown Layer Breeders

摘要

This study was aimed at determining the internal and external quality traits of the breeding eggs of Isa Brown layer breeders as well as the phenotypic correlations between these traits. A total of 120 eggs collected during the first laying cycle wereused for this study. The birds were reared on deep litter at Ajanla Farm, Ibadan, Southwest, Nigeria. The values related to egg weight, egg width, egg length, shell thickness, shell ratio, shape index and shell weight were found, respectively as 55.90 g, 4.24, 5.57 and 0.27 cm, 10.05%, 76.18% and 5.62 g while yolk weight, yolk width, yolk height, albumen weight, albumen width, albumen height, haugh unit, yolk ratio and albumen ratio were found respectively as 14.35 g, 3.84 cm, 1.77 cm, 35.94 g, 6.93 cm, 8.60 mm, 93.21, 25.74 and 64.24%. According to the results obtained in this research, almost all internal quality traits of the eggs were influenced at significant levels depending on the change that occurred in the egg weight with respect to the external quality traits of the egg except yolk ratio. These results suggest that it was possible to use egg weight in determining the egg length, egg width and eggshell weight. Both yolk height and albumen height significantly influenced haugh unit and this implies that these traits could be used to determine the value of haugh unit rather than any other internal quality traits.