We have pedigree information on the pigs in this data set extending across seven generations, corresponding to years in the data set. The first generation for which we have phenotype data is from year 2004, and we have pedigree information on the direct parents of those pigs. That previous parental generation is a base generation for making inferences about genetic parameters. We assume that each parent in the first generation of the pedigree was sampled at random from the reference population, so we assume that all of those parents have no genetic relationships among themselves (all coefficient of ancestry values, θ, = 0 for that generation). The pedigree data are available in the file “pig_pedigree.txt”: