Genetic Analyses of Generation Means for a Cross Between Two Local Breeds of Chickens: 4- A Model for Hatchability Prediction as a Function of Some Egg Quality Trait

Abstract

This study was undertaken to predict hatchability as a function of some physical characteristics of eggs in the third generation (F 3 ) and backcrosses (BC 1 and BC 2 ) derived from crossing between two local developed strains of chickens (Gimmizah and Bandarah). The physical parameters used in this study were egg weight, egg shell thickness, egg shape index and yolk/albumin ratio as well as obtained hatchability. The relationships of these parameters in hatchability process were modeled by multiple linear regressions. The performances of the three genetic groups (F 3 , BC 1 and BC 2 ) were used to apply the modeling process. The following model output: Y = 241.6 + 1.126 x 1 + 213.5 x 2 + 79.54 x 3 + 28.03 x 4 , where Y presents the predicted hatchability, 241.6 presents the intercept parameter (α) and the 1.126, 213.5, 79.54 and 28.03 are the slope parameters (βi) of egg weight (x 1 ), shell thickness (x 2 ), egg shape index % (x 3 ) and yolk/albumin ratio (x 4 ), respectively. Furthermore, the mention approach above confirms the existence of a highly significant relationship between the main regression parameters and predicted hatchability.