Estimation of Genetic parameters of Weekly Bodyweight and Growth Rates of Japanese quail

The Harvey Mixed Model Least-squares and Maximum Likelihood Computer Programme was used to estimate the heritability, genetic and phenotypic correlations of live body weight and growth rates of 684 Japanese quails. The results revealed that Japanese quails are sexually dimorphic for live body weight at all ages. Heritability of live body weight ranged from 0.12±0.02 to 0.91±0.11. All genetic correlation between live body weights were positive. Phenotypic correlations between live body weights at all ages were positive and very highly significant (P<0.001). The heritability estimates for growth rate ranged from 0.20±0.07 to 0.62±0.04. Genetic correlations between growth rates ranged from -0.51 to 1.11. Phenotypic correlations among growth rates varied from -0.02 to 0.76. It was concluded that selection for live body weight within the first two weeks of age may lead to improvement of body weight at later stages of life, and, mass selection for growth rate may lead to rapid improvement in growth rate.