Evaluation of control populations: body weight and rate of gain in Japanese quail.

1. Two control populations of quail of different origin were maintained by cyclical mating, one for 4 and the other for 6 generations. Means, heritabilities, genetic and phenotypic correlations of body weights at 1, 14 and 35 d and rates of gain from 1 to 14 d and from 14 to 35 d did not show any trend of change with generation. 2. The variability between generations was greater in the characters having intermediate and lower values of heritability, genetic and phenotypic correlations than in those with higher values.