Animal Industry Report

Extension Number

ASL R3274



Summary and Implications

In two independent populations of pigs, divergent selection for increased and decreased feed efficiency, measured as residual feed intake (RFI), was performed over ten generations in purebred Yorkshire pigs at Iowa State University (ISU) and eight generations in French Large White pigs at the French National Institute for Agricultural Research (INRA). Over time and generations, favorable alleles for improved feed efficiency were expected to increase in frequency in the more feed efficient (Low RFI) lines, while unfavorable alleles decrease, and vice versa in the less feed efficient (High RFI) lines. When changes in allele frequency over time are more extreme than what could be caused by genetic drift, this indicates a selection signature. Genes that are important in both populations were expected to have overlapping selection signatures. In this study, two such selection signatures were identified for RFI, on chromosomes 2 and 13, with candidate genes related to protein turnover rate and mitochondrial function. These selection signatures give insight into the genetic basis of feed efficiency in pigs and markers in these regions can be used to select for more feed efficient pigs.

Copyright Holder

Iowa State University