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
This study was undertaken to predict hatchability as a function of some physical characteristics of eggs in the third generation (F3) and backcrosses (BC1 and BC2) 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 (F3, BC1 and BC2) were used to apply the modeling process. The following model output: Y = 241.6 + 1.126 x1 + 213.5 x2 + 79.54 x3 + 28.03 x4, 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 (x1), shell thickness (x2), egg shape index % (x3) and yolk/albumin ratio (x4), respectively. Furthermore, the mention approach above confirms the existence of a highly significant relationship between the main regression parameters and predicted hatchability. Contrarily, determination coefficients adjusted (R²) were found to be 0.08, 0.11 and 0.13 in F3, BC1 and BC2, respectively. These R2 were closer to 0 indicates a regression line did not fit the data.
