Genetic and environmental control of ovarian function in turkeys at sexual maturity.

1. The relationships between the numbers of ovarian yellow follicles and body weight was investigated in four strains of turkeys photostimulated at 24 or 30 weeks of age. The birds were fed ad libitum or control fed to reach 0.8 or 0.6 of the body weight of ad libitum-fed birds at 24 weeks of age. 2. There were more yellow follicles at 24 compared with 30 weeks of age. 3. The number of yellow follicles was higher in bigger strains. 4. Body weight control reduced the number and the proportion of similar sized yellow follicles. The effect decreased with increasing strain body weight. 5. There was a linear relationship of 0.633 between log yellow follicle number and log body weight. The intercept was higher in turkeys photostimulated at 24 compared with 30 weeks of age.