DIVERGENT SELECTION FOR GROWTH IN JAPANESE-QUAIL UNDER SPLIT AND COMPLETE NUTRITIONAL ENVIRONMENTS .6. DIFFERENTIAL BODY WEIGHTS IN RECIPROCAL CROSSES

Growth patterns were investigated in reciprocal crosses of quail lines divergently selected for 4-wk BW. In Experiment 1, quail from two set s of high lines (H), and two sets of low lines (L), and their reciproc al crosses (HL and LH) from Generation 23 breeders were reared intermi ngled and fed a 28% CP diet. Individual BW data were collected weekly through 9 wk. Experiment 2 involved only reciprocal cross progeny (HL, LH) from Generation 26 breeders with quail placed in divided decks of battery brooders to allow collection of feed intake and feed efficien cy (FE) data. Feed intake data were collected from 0 to 38 days and BW data from 0 to 69 days. Quail from the LH cross were significantly (P < .05) larger than quail from the HL cross from 0 to 14 days and 0 to 69 days in Experiments 1 and 2, respectively. Initial BW differences were expected because of the large egg size difference between H and L line dams; however, persistent BW differences were not anticipated. I nitial feed intake was greater (25%) for LH than HL quail; however, wh en adjusted for BW, HL quail consistently consumed more feed per gram of BW than LH quail. Feed efficiencies were not significantly differen t for the two genotypes; however, smaller HL quail tended to have supe rior FE after 2 wk of age. Initial relative growth rates were 17 to 38 % higher in HL quail; however, after Week 2 absolute gain was essentia lly identical for the reciprocal crosses.