Genetic groups of unknown parents are extended to the multitrait animal model. Computationally feasible mixed model equations are obtained. A strategy to include genetic groups for missing data is proposed. Canonical and triangular transformations can be applied to the multitrait animal model with groups if the transformations can be applied to the same model without groups. Formulations for REML estimation with groups are derived, and the results are almost as feasible as REML estimation without groups. A numerical example is given to illustrate computations of REML formulations.
- animal model
- genetic group