A generational comparison of some quantitative traits in three Japanese quail lines

Abstract
This study was to evaluate the performance of three Japanese quail lines over four generations concerning body weight at sexual maturity (45 days), 90 days, and 120 days, as well as egg production. Fifty-four one-day-old chicks from each quail line were raised and assigned to experimental groups, with a sex ratio of one male to two females. The birds were provided with starter feed up to 30 days and production feed from 30 to 120 days. The body weights were recorded at three stages (sexual maturity, 90 days, and 120 days), and egg production was assessed at 90 and 120 days. The results indicated that at sexual maturity, Body weight did not differ significantly across the three lines (p≤0.05). However, at 90 and 120 days, the Brown line had significantly higher body weights compared to the Gray and White lines (p≤0.05). Across generations, body weight decreased progressively, with the highest values recorded in Generation 0 and the lowest in Generation 3, likely due to cumulative genetic selection effects. Egg production also varied significantly among lines, with the Brown line consistently outperforming the White and Gray lines at both 90 and 120 days (p≤0.05). Generation 0 demonstrated the highest egg production, which declined progressively through Generation 3. A significant positive correlation was found between body weight at sexual maturity and subsequent body weights at 90 and 120 days, indicating that early weight measurements can serve as reliable predictors of long-term growth performance.