Document Type : Research Paper
Assistant Professor, Faculty of Agricultural Science, Payame Noor University, Tehran, Iran
Assistant Professor, Faculty of Agricultural and natural resources, Lorestan University, Khorram-Abad, Iran
The aim of this research was to estimate genetic parameters for mean and residual of body weight in Japanese quail. A total of 2629 quail body weight records at 28 days old were used in this research. Double hierarchical generalized linear model (DHGLM) was used to estimate (co) variance components using ASREML 4.0 software. Additive genetic variance for mean and residual were 189.59 and 0.18, respectively and were statistically significant (p<0.01). The genetic standard deviation for residual of body weight was 0.42. Therefore decreasing estimated breeding value of residual by 1 genetic standard deviation can increase the uniformity of body weight at 28 days old by 42%. Heritability for mean (0.51) was larger than the heritability for the residual (0.02). Although heritability for residual was low but it was significant (p<0.01). The Spearman rank correlation between estimated breeding values in mean and dispersion was low (0.094). Low and unfavorable genetic correlation (0.09) was obtained between mean and residual. The results obtained in this research show the residual of body weight records at 28 days old is under control of additive genetic variance and uniformity can be achieved by means of genetic selection.