Descriptive statistics for the populations.

N. phenotypes = number of sows with phenotyp ic data; N. genotypes = number of sows with genotyp ic and phenotyp ic data; Mean parity n = mean parity number corresponding to the phenotypes in the data; Mean = mean of the phenotype data, averaged over all parities; = (uncorrected) standard deviation of the phenotype data. 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.