ANIMAL-MODEL ANALYSIS OF GENETIC (CO)VARIANCES FOR GROWTH TRATIS IN JAPANESE-QUAIL

Records of 1,530 Japanese quail were used to estimate heritabilities a nd genetic correlations based on a derivative-free restricted maximum likelihood (REML) method with an animal model and ANOVA. The animal mo del included fixed effects of hatch and sex, random effects of additiv e genetic value of the bird, and common environmental effect of the da m. Heritabilities estimated from REML for body weights at hatch, 7, 14 , 21, and 28 d of age were .38, .12, .31, .12, and .44, respectively. Heritabilities estimates from the sire component of variance for the s ame traits were .57, .08, .28, .15, and .47. These values indicate tha t genetic progress can be made by selecting for either 14-d or 28-d bo dy weight. Genetic correlation (REML) of .76 between body weights at 1 4 and 28 d of age indicates the possibility of improving body weight a t 28 d of age by selecting for body weight at 14 d of age.