Estimation of Genetic Parameter in the Selected Layer Chicken Derived from a Diallele Crossed Population

Abstract

Crossbred layer chickens derived from a diallele crossed F₁ population were selected as a parental stock. Artificial inseminations were performed to generate F₂ progenies. The traits of the F₂ population considered were the age of first egg (AFE), the average egg weight at 262 days of age (EW), and the egg number at 262 days of age (EP). The data were analyzed for genetic parameters using 2 methods; the least squares by analysis of variance (ANOVA) and the restricted maximum likelihood (REML). The linear statistical model used in this experiment was sire-dam model. The means of AFE, EW and EP in the F₂ population were better than those in the parents (F₁) at the values of 5.4 days, 2.04 grams, and 0.34 eggs, respectively. The error variance (  ) analyzed with ANOVA and REML manifested nearly the same values for each trait in this study. The heritability value computed from sire component ( ) for all traits were high and similar to those obtained from the two analysis methods. Nevertheless, the heritability value calculated from dam component (  ) revealed a low value for AFE and EP and a medium value for EW. The genetic correlation calculated from sire + dam component (r_G(s+d)) between the AFE-EW, AFE-EP and EW-EP were -0.025, -0.824, and -0.333, respectively. However, the genetic parameters analysed using REML method under the sire-dam model in the selected layer population of this study did not show higher efficiency and accuracy than those using the ANOVA method.