不同类群大白猪窝产仔数的遗传分析

Genetic Analysis of Litter Size in Different Large White Lines

对双肌臀大白猪和普通大白猪组成的 561窝产仔数的资料进行了遗传分析。结果表明 :公猪和胎次均对母猪产仔数 (总产仔数和活产仔数 )具有极显著影响 (P <0 .0 0 1 ) ,季节和类群均对母猪产仔数 (总产仔数和活产仔数 )具有显著影响 (P <0 .0 5)。大白猪产仔数的平均值随胎次增长而增加。夏季分娩的大白猪具有最高的产仔数 ,依次为春季和冬季 ,秋季最低。大白猪总产仔数和活产仔数的遗传力分别为0 .0 9和 0 .1 0 ,属低遗传力 ,直接选择窝产仔数几乎没有效果 ;它们之间的遗传相关为 0 .80 ,表型相关为0 .85,环境相关为 0 .90 ,它们之间的协遗传力为 0 .0 8。这些参数表明总产仔数和活产仔数是两个不同的性状 ,在生产实践中单独记录它们是有理由的、必要的。

Genetic analyses were conducted on the data of 2 populations with 561 litters in Large White pigs.The results indicated that both boar and parity had highly significant(P<0.001)effects on the litter size in sows, both season and line had significant (P<0.05) effects on the litter size in sows. The means of the total number born and the number born alive increased with the increasing parity. The sows farrowing in summer had the highest litter size, while the lowest litter size reached in autumn. The litter size was higher in spring than in winter. The heritability estimates for the total number born and the number born alive were 0.09and 0.10,respectively. Phenotypic,genetic and environmental correlations between the total number born and the number born alive were 0.80,0.85 and 0.90,respectively. The coheritability for the total number born and the number born alive was 0.08. These parameters showed that the total number born and the number born alive were two different traits,that it was reasonable and necessary to independently record them in the production practice.