A. Ayatollahi Mehrgardi - Department of Animal Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran

The Japanese quail has been utilized as a research species in establishing the genetic relationships that may also be present in other species. Divergent phenotypic selection for 4-wk BW was conducted for three generations in high (HW) and low (LW) lines. Within each line, 50 females and 25 males were selected among 600 birds, based on 4-wk BW. Mean BW at 4 wk of age in the base generation was 186.2 and 178.6 g for females and males, respectively. In the 3rd generation, the mean of 4-wk BW for male and female birds was 214.5 and 208.1 in HW line and 173.5 and 167.8 in LW lines, respectively. The realized heritability was estimated as 33.4% and 28.3% for females and males in HW lines and 20.3% and 20.2% for females and males in LW lines. The results suggested the effectiveness of phenotypic selection for body weight in Japanese quails, although the hatchability decreased in the heavier birds.

divergent selection, realized heritability, Japanese quail