Extension of Environmental Descriptors Used to Analyse Sire by Environment Interaction for Growth of Pigs

Abstract

Environmental descriptors based on contemporary group estimates of average daily gain (ADG), backfat (BF), daily feed intake (DFI) and muscle depth (MD) were used to evaluate sire by environment interactions (S×E) for growth rate of pigs. Further, these descriptors were combined using principal component analysis and the first principal component (PC1) was used as an overall environmental descriptor. Use of the environmental descriptors based on MD, BF and DFI did not detect any S×E for growth. However, significant S×E was detected using the environmental descriptor based on ADG and also the overall descriptor based on PC1, where the S×E variance components accounted for 2.1% and 1.8% of the phenotypic variance. While an environmental descriptor that encompasses more traits is expected to capture more environmental variation, use of the environmental descriptor based on ADG alone may be adequate to describe phenotypic variability attributed to S×E for growth.