Broiler의 體重에 對한 相加的 및 非相加的 遺傳分散成分의 推定

Estimate of Additive and Nonadditive Genetic Variance Components for Broiler Body Weight

This study was conducted to investigate the combining abilities and nonadditive genotype-environmental interaction for broiler body weight at 2, 4, 6 and 8 weeks of age. A total of 1181 progenies were obtained from a full diallel cross of three broiler strains. The estimated heterosis at 2, 4, 6, and 8 weeks of age were 0.43%, 0.79%, 0.99%, and 0. 30% respectively. Heterosis difference by weeks suggested that difference of growth rate between strains and crossbreds. At: all ages of mesurements in both male and female for body weights, averaging additive genetic variance due to sire variance was 11.46%, 17.48%, and averaging maternal effect was 51.69%, 32.38%, respectively. The environmental variance components due to tier effect were decreased in according with increasing of weeks of age. The male progeny was more influenced than female progeny by environmental effect. Nonadditive genetic variance due to genotype interaction in male and female were averaging 3.68%, 4.14%, respectively. Nonadditive genotype-environmental interaction components, Sire × Tier, Dam × Tier, Sire × Dum × Tier, were averaging 1.85%, 9.53%, 28.17% for body weight, respectively. Generally, the ratios of this variance component were decreased in according with increasing of weeks of age.