[Genetic analysis on litter size in pigs].

Genetic analysis was conducted on the data of 3 populations with 1,686 litters including Erhualian pig, Large White and first cross. The results indicated that the heritability estimates for the total number of piglets born, the number of piglets born alive, the number of piglets at 20 d and at 45 d were 0.081, 0.156, 0.402 and 0.419, respectively. The major gene index analysis indicated that the prolificacy of Erhualian pig was influenced by major genes.