蛋鸡产蛋量遗传规律及对育种选择的启示

Genetics of Egg production in Layers and its importance to Selection

产蛋量性状的遗传力随产蛋周龄的增加表现出前高中低后回升的变化趋势。不同定义的遗传力其遗传规律及生物学意义也不同。前期产蛋量与６０周龄产蛋量的遗传相关随周龄增大而增大，一般在３６—４０周龄后均具有育种意义。３６周龄的体重和蛋重与总蛋重间为强正遗传相关。从选择效率来看。

Heritabilities etimated for laying traits in four layer lines using MIVQUE indicated a simitar trend of variation,with the greatest magnitudes in the beginning periods of lay,followed by the lowest in the middle,and a upward tendency in the ending periods.Genetic variation and biological importance of egg production traits depend on their definitions.Genetic correlations between egg production at 60 weeks of age and earlier partrecord egg productions increase with age,and are normally of selection importance after 36 to 40 weeks of age.Body weights and egg weights at 36 week of age are positively associated with egg mass up to 60 weeks of age.Selection on egg mass migth be better than on egg number in view of selection efficiency.