Economic implications of environmental variation observed in a pig nucleus farm in Australia

The performance of a group of pigs, adjusted for other known systematic and genetic effects, can be used to quantify environmental variation (EnVar) on farms. Using such an approach, Li and Hermesch (2015) found variation between environments for average daily gain (ADG) and backfat (BF) in nucleus herds with good management and high health status that was similar to the genetic variation. In that study, EnVar for daily feed intake (DFI) and feed conversion ratio (FCR) could not be assessed because data for DFI were not available. The economic implications of EnVar may be evaluated by multiplying differences in group means for each trait by the corresponding economic value (EV) (Hermesch et al. 2014). An EV for a trait quantifies the change in profit when the trait is changed by one unit. It is independent from other EVs and can be applied to other non-genetic factors. We hypothesised that EnVar exists in a nucleus farm for ADG, BF, DFI and FCR leading to economic differences between environments.