Variance components estimated.

Additive variance (), permanent environment variance (), variance of the maternal effects (), residual variance () and heritability (h) (with standard errors) estimated for the four traits in populations C1 and C2. The traits included in the analyses were: LB = number of piglets born alive in a litter, LW = weight of the liveborn piglets in a litter in kg; TB = number of piglets born in a litter; TW = weight of the piglets born in a litter in kg.