Effects of acyl-CoA:diacylglycerol acyl transferase 1 (DGAT1) gene on milk production traits in crossbred Holstein dairy cattle.

The objective of this study was to analyze and investigate the genotype frequency and the association between Acyl-CoA:diacylglycerol acyltransferase1 gene, DGAT1 gene, and milk yield (MY), milk composition, protein yield (PY), fat yield (FY), solid not fat yield (SNF), total solid (TS), the content of fat, protein, solid not fat, and total solid, (%Fat,%Prot,%SNF,%TS) in two herds of crossbred Holstein dairy cattle in Thailand. Two hundred and twenty-seven crossbred Holstein cows were used and their blood samples were taken for the study. PCR-RFLP was used to identify the allele and genotype of DGAT1 gene. A general linear model and the least square method were used to estimate the least square mean and additive, and the dominant effect of the gene on the traits and the least significant differences were used to compare the mean of each trait between genotypes. Two alleles (K, A) and three genotypes (AA, KA, KK) were detected, the highest allele and genotype frequencies were A and AA, respectively. The least mean squares of each genotype were compared and significant differences between genotype were detected. Genotype KK has the greatest effect on all milk composition content traits, while genotype AA has the greatest effect on yield traits. Highly significant additive gene effect was detected. From the results, it can be concluded that the DGAT1 gene can be used as a gene marker for assisted selection in milk composition traits.