A Whole Genome Association Study to Detect SNPs for Growth and Carcass Qualtiy Traits in Korean native cattle, Hanwoo

A whole genome association (WGA) study was conducted to detect SNPs for growth and carcass traits in Korean native cattle, Hanwoo. The data set comprised 61 sires and their 486 steers that were born between the spring of 2005 and the fall of 2007 for progeny testing in the Hanwoo Improvement Center in Seosan, Korea. The sires and steers were genotyped with the 39,501 SNPs in the Illumina bovine SNP 50K chip. A total of 16(0), 18(4), 20(13), 11(23), 10(13) and 19 (1) SNPs were detected at the 5% chromosome (genome)-wise level for weaning weight (WWT), yearling weight (YWT), carcass weight (CWT), backfat thickness (BFT), longissimus dorsi muscle area (LMA) and marbling score (Marb), respectively. Among the 148 SNPs, 91 SNPs had dominance effects, suggesting that dominance inheritance mode be considered in genetic improvement for growth and caracass quality in Hanwoo. The SNPs were located at 35 chromosomal regions (QTL) in 17 Bos taurus chromosomes (BTAs), including a QTL for CWT on BTA14 with a strong statistical significance. Also, several QTL for WWT, YWT, BFT, and LMA were detected in BTA20. Further studies on finding candidate genes in the QTL regions are on progress to efficiently implement marker-assisted selection in commercial Hanwoo populations.