Correlated Responses in Sow Feed Intake, Body Composition and Reproduction after Divergent Selection for Residual Feed Intake in the Growing Pig

Abstract

Residual feed intake (RFI) represents the fraction of total feed intake which is not "explained" by maintenance and production requirements. Selection against RFI was suggested as a tool for increasing feed efficiency while having no correlated change in production traits (Kennedy et al. 1993). A divergent selection experiment on RFI is currently being carried out in the Large White breed; six generations of selection have been completed. Previous studies in mice and cattle (Hugues and Pitchford 2004; Meyer et al. 2008) found low to moderate correlations of RFI in growing animals with traits recorded in mature females. Moreover, the ability of sows selected for higher lean meat growth to sufficiently provide nutrients to piglets during lactation has been questioned. This study was performed to estimate genetic parameters and correlated responses for feed intake, body composition and reproduction traits of sows in lines selected divergently for RFI during growth.