The DGAT1 gene K232A mutation is associated with milk fat content, milk yield and milk somatic cell count in cattle (Short Communication)

Abstract. The present study investigated the K232A mutation of the diacylglycerol O-acyltransferase 1 gene (DGAT1) in 315 Czech Holstein Cows. The allele frequency was found to be 0.19 for the K allele and 0.81 for the A allele. The results ofK232A testing were assessed in relation to average daily milk yield (l), percentage of fat, protein, lactose and milk somatic cell count (SCC, thousand/ml). A GLM procedure was used to analyse the differences among genotypes. The K232A genotypes were significantly associated with milk fat percentage (KK, KA>AA [P≤0.005, P≤0.05]) and milk yield (KK, KA>AA [P≤0.05, P≤0.005]). The K allele was also favourable for SCC levels: cows with the KA genotype had lower SCC levels than those with the AA genotype (P≤0.05), while cows with the KK genotype showed the lowest levels of SCC at all. This new association of K232A suggests the existence of another gene in the centromeric region on BTA14 linked to DGAT1 with direct effect on the SCC. On the basis of a broad range of DGAT1 protein functions and the non-conservative matter ofK232A, a direct effect of K232A on the SCC cannot be ruled out either.