Abstract #17

# 17
Application of genomic technologies to improve feed efficiency traits in swine.
Kent A. Gray*1, 1Smithfield Premium Genetics, Rose Hill, NC.

One challenge that faces the US pork industry is the efficient use of feed resources as feed costs continue to be the largest variable expenditure. Typically, feed efficiency is measured as feed conversion ratio (FCR) or calculated through residual feed intake (RFI). Regardless of the measure defined as feed efficiency, average daily gain (ADG) and average daily feed intake (ADFI) remain the 2 main components for estimating nutrient utilization traits. Several studies demonstrate improvement of feed efficiency through selection programs focused on improving either FCR or RFI. However, these programs require recording individual feed intake, which is labor intensive, time consuming, and requires specialized equipment. Additionally, data from feed intake recording equipment (FIRE) systems contain several data errors that require careful editing before the data can be used. With the introduction of advanced genomic technologies in livestock species there is an opportunity to improve selection of feed efficiency. Genomic tools have helped us identify genomic regions associated with feed efficiency and other production traits through whole-genome association studies. One region in particular located on SSC1 ranging from 166 to 170 Mb was significantly associated with ADFI, ADG, and backfat (BF), where SOCS6 and DOK6 are proposed as the most likely candidate genes. The use of whole-genome selection methodologies can also be used to improve response to selection by increasing accuracy. Variance components were estimated with AIREML and (G)EBV were computed with either BLUP or single-step genomic BLUP (SSGBLUP). Comparisons of reliabilities between traditional BLUP estimates and SSGBLUP estimates indicate that GEBV estimates for FCR and component traits BF, ADFI, ADG, and off-test weight (WT) have increased reliabilities by 9% to 60% when compared with traditional EBV estimates. Because of this increased accuracy, we can conclude that application of genomic technologies will help us improve feed efficiency traits in swine.

Key Words: feed efficiency, swine, genomic selection

Speaker Bio
Kent Gray was raised on an asparagus and alfalfa farm in southeastern Washington.  Kent obtained a B.S. from Brigham Young University majoring in Genetics and Biotechnology.  Kent continued his education at NC State University where he received a MS and PhD in Animal Breeding and Genetics with a minor in Statistics.  In 2011 he started working at Smithfield Premium Genetics as a Research Scientist. Kent currently resides in Rocky Point, NC with his wife and four children and continues to work at Smithfield Premium Genetics as the Director of Genetic Research and Development.