Divergent selection for residual feed intake alters whole body tissue accretion rate in growing pigs

摘要

Residual feed intake (RFI) index is a measure of feed efficiency (FE) we define as the difference between the actual feed intake of a pig and its expected feed intake based on a given amount of growth and backfat. After six generations of selecting Yorkshire pigs based on RFI at Iowa State University, a unique resource population of pigs has been created to study the genetic and physiological basis of FE (Young and Dekkers, 2012). Therefore, selecting pigs with a low RFI has resulted in a more feed efficient animal for a given rate of growth. Our objective was to determine the extent to which whole body tissue accretion rates contributes to FE differences in pigs divergently selected for RFI in the seventh generation.