Notice that we also included in the model the term ‘us(2 !GUUU).nrm(pig)’ to permit the variance covariance structure of the estimates for this term to be unconstrained (i.e., correlations based on the variance and covariance components are allowed to go out of bounds, greater than 1.0 or less than -1.0). This only needs to be done if we want to add qualifiers to the model term specified in the str() function. We cannot include the qualifiers directly in the str() function, i.e., ‘str(pig dam us(2 !GUUU).nrm(pig))’ will not be read as a valid random term, so we specify the same variance structure already given in the str() function a second time and include the qualifiers in this second specification.
OUTPUT PART 3: This model produces the following result: