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 ...