Genetic Parameters and Genome-Wide Association Studies for Body Size Traits of Shuxuan Cattle in China

In domestic cattle, the body size traits have important implications in terms of breed characteristics and production performance. Shuxuan cattle is a dual-purpose breed mainly raised in Sichuan province, China, for which we have known less about the genetic parameters and underlying candidate genes in relation to the body size traits. In this study, we obtained the genome-wide single nucleotide polymorphisms (SNPs) using the Illumina Bovine BeadChip in 275 Shuxuan cattle. These SNPs were first used for estimating genetic parameters for the withers height (WH) and diagonal body length (BL). Using the bivariate animal model, the estimates (±standard error) of heritabilities were 0.71±0.22 and 0.49±0.29 for BL, and their genetic correlation was 0.64±0.37. Second, the genome-wide association study (GWAS) was performed. However, these did not result into genome-wide significant SNPs for both WH and BL traits. According to a less stringent suggestive significance, some positional candidate genes were found, and some of them (such as FAM110B, TAS1R2, PAX3, and FHIT) were previously reported in literature to be associated with body size traits in cattle. In conclusion, we estimated the genetic parameters in Shuxuan cattle using genomic information for the first time, which are required for implementing the genomic selection programs in the future.