Changes in Unselected Traits Accompanying Long-Term Selection for Four-Week Body Weight in Japanese Quail

The changes in unselected traits following long term selection for high 4-week body weight were evaluated in two Japanese quail lines. Means of these traits (16-week body weight, age at first egg, egg weight, egg production, fertility, and hatchability) of breeders were also used to obtain estimates of trends across generations by regressing line means on generation number. Differences between lines for all traits except percentage hen-day egg production were significant. Body weights and egg weights of the selected lines were larger than corresponding measurements in the nonselected line, whereas fertility and hatchability measurements were larger in the nonselected line.