Here we use the str() function in ASReml to indicate that the terms inside the parentheses use the same Z matrix to relate observations to parameter values. In this case, we specify two model terms, pig and dam, that share a common structure. Since we have specified both of these terms as pedigree-associated factors using the !P qualifier in the field definitions, ASReml associates both of these terms with the pedigree information we supplied. That information, in turn, is used to model the variance-covariance structure of the pig and dam effects based on the additive genetic relationship matrix. In the previous model, where we just specified pig alone as a random pedigree-associated effect, we also estimated both progeny and dam breeding values as random effects from a common distribution. What is new here is that we are separating the effects of each pig into its own direct genetic effect on weaning weight and also into a maternal genetic effect (if it was female and was a mother to some phenotyped offspring), where the variancecovariance structure of the effects is proportional to the A matrix. In other words, we are modeling both the breeding value of the pig itself and the effect of its mother on its weight, where both effects have covariances among individuals determined by their coancestries.