PSXI-5 - Genome-wide association study of feed efficiency in Russian Duroc boars

The cost of fodder is the major part in expenditure in pork industry. In this regard, improving the feed efficiency is the main goal of breeding programs for the most of pig breeds. Residual feed intake (RFI) is an alternative measure for feed efficiency, which is accepted in different livestock species including pigs. RFI is defined as the difference between the observed and predicted feed intake based on average daily gain and (additionally) back fat thickness. Our aim was to find the candidate genes responsible for RFI in Russian Duroc boars. RFI values for individual boars (n = 766) were calculated using linear regression of daily feed intake on metabolic mid-test weight and average daily gain. The SNP genotyping was carried out using Porcine GGP HD BeadChip (GeneSeek/Neogene). After data quality control, performed in PLINK 1.9, 43,199 SNPs were selected for genome-wide association studies (GWAS). The average daily gain in studied boars was 957 g with variation in individual animals from 424 to 1508 g. Feed conversion rates averaged to 2.21 kg/kg with variation from 1.8 to 3.7 kg/kg. GWAS results showed the presence of 48 SNPs, which were significantly (P < 0.00001) associated with RFI, including 15 SNPs on SSC2, 9 SNP – SSC4, 2 SNPs – SSC6, 21 SNPs – SSC9, and 1 SNP – SSC17. A search for genes located within 0.4 Mb window (0.2 Mb down-stream to 0.2 Mb up-stream from identified SNP) revealed several putative candidates. Functional annotation of the obtained candidates showed the presence of genes involved in protein metabolism (ADAMTS2,UIMC1 on SSC2; NTNG1 on SSC4), regulation of glucose and bile acid metabolism (FGFR4 on SSC2), neuronal development (ENC1 on SSC2; NTRK1, MEF2D on SSC4), vitamin D and K pathways (BGLAP on SSC4). The study was funded by the Russian Ministry of Science and Higher Education No.0445-2019-0029.