Abdominal fat and testes weights in diverse genetic lines of Japanese quail

Six experiments were conducted to investigate abdominal fat levels in mature male and female Japanese quail following selection for 4-wk body weight and to investigate the relationship between testes development and abdominal fat accumulation. The present study utilized P-, T-, and S-line quail selected for more than 75 generations for high 4-wk body weight and also lines divergently selected (16 or more generations) for high (H-SD, H-CD) and low (L-SD, L-CD) 4-wk body weight. Adult males had from two to four times more abdominal fat than females, the reciprocal of abdominal fat patterns in chickens. These differences were observed regardless of the selection environment, direction of selection, or duration of selection. Percentage of abdominal fat was higher in high body weight lines than in low body weight lines, and correlation coefficients between body weight and abdominal fat were moderate to high (mean = .39). Correlations between abdominal fat and testes weights were positive and largest at 5 wk (r = .62).