Genetic parameter estimates and principal component analysis on performance and carcass traits of a terminal pig sire line

This study aimed to estimate genetic parameters for five traits related to performance and carcass in a terminal pig sire line using multitrait (MUV) and reduced rank animal models, and to analyze the relationship between the breeding values (EBVs) of the traits using genetic principal component analysis (PCA) applied directly on the mixed model equations (one-step PCA) and on the EBVs obtained using the MUV (two-step PCA). The heritabilities were very similar using both procedures ranged from 0.032 +/- 0.014 for feed conversion to 0.102 +/- 0.029 for lean meat. Except for some differences in the heritability for feed conversion ratio, the heritability estimates were remarkably similar using One-step PCA or MUV. The genetic correlations obtained using One-Step PCA were more reliable due to their lower standard errors compared to those obtained using MUV. The one-step PCA had better fit than MUV and could reduce the time computing due to the reduction of the additive genetic matrix.