GROWTH UNDER DIFFERENT NUTRITIONAL ENVIRONMENTS FOLLOWING SELECTION IN JAPANESE-QUAIL UNDER SPECIFIC ENVIRONMENTS

A study was conducted to investigate growth in quail lines selected un der three nutritional environments when lines were exposed to several environments. Lines utilized were the P line selected for high 4-wk BW under a 28% CP diet, the T line selected for high 4-wk BW under a 20% CP diet containing .2% thiouracil (TU), and the S line derived from t he T line in Generation 27 and thereafter selected for high BW under a 28% CP diet containing .2% TU. The randombred control (C) from which these lines originated was also utilized. In Experiment 1, quail proge ny from Generation 70 breeders were fed diets containing 28% CP with 0 , .05, .10, .20, and .40% TU added to the diet. In Experiment 2, P, T, S, and C progeny from Generation 72 breeders were evaluated under the three selection environments. Body weights were obtained weekly from 0 to 4 wk. In Experiment 1, P line quail had superior BW on the contro l diet whereas S and T line quail had superior BW on diets containing TU. Increasing TU levels resulted in progressive decreases in P and C line BW, however, TU had only minimal effects on BW in S and T line qu ail, resulting in line by diet interactions. In Experiment 2, the high est BW was found in quail receiving the 28% CP diet, however, all sele cted lines had superior BW to other lines under their respective selec tion environments. Across diets, T line quail had the highest 4-wk BW and P line quail had the lowest BW. The best overall performance was o btained from the line selected under the poorest environment.