A whole genome association study was conducted to identify SNPs with additive and
dominant effects for growth and carcass traits in Korean native cattle, Hanwoo. The
data set comprised 61 sires and their 486 Hanwoo steers that were born between
spring of 2005 and fall of 2007. The steers were genotyped with the 35,968 SNPs that
were embedded in the Illumina bovine SNP 50K beadchip and six growth and carcass
quality traits were measured for the steers. A total of 18 (0), 15 (3), 12 (8), 15 (18) , 11
(7) and 21 (1) SNPs were detected at the 5% chromosome (genome) - wise level for
weaning weight, yearling weight, carcass weight, backfat thickness, longissimus dorsi
muscle area and marbling score, respectively. Among the significant 129 SNPs, 56
SNPs had additive effects, 20 SNPs dominance effects, and 53 SNPs both additive
and dominance effects, suggesting that dominance inheritance mode be considered in
genetic improvement for growth and carcass quality in Hanwoo. 33 QTL regions on
18 Bos Taurus chromosomes (i.e. BTA 3, 4, 5, 6, 7, 9, 11, 12, 13, 14, 16, 17, 18, 20,
23, 26, 28 and 29) were detected. There is strong evidence that BTA14 is the key
chromosome affecting CWT. Also, BTA20 is the key chromosome for almost all traits
measured (WWT, YWT, LMA). The identification of growth and carcass traits
associated SNPs and mapping of the corresponding QTL in small chromosomal
regions reported will facilitate searches for candidate genes in Hanwoo.