Milk productivity and milk quality of cows with different DGAT1 genotypes and linear affiliation

A review of the scientific literature has shown that the genotype by loci of the diacylglycerol-O-acyltransferase ( DGAT1 ) gene and linear affiliation to the leading Holstein breed of cows have an impact on milk productivity and the quality of their milk. The purpose of our research was to study the milk productivity and qualitative composition of the milk of Tatarstan-type cows with different genotypes according to the loci of the diacylglycerol-O-acyltransferase gene and linear belonging to the Holstein breed. The research was carried out in the conditions of the agricultural company "Agrofirma Rassvet" of the Kukmorsky district of the Republic of Tatarstan on the livestock of 79 cows of the Tatarstan type. As a result of a molecular genetic study (PCR-RFLP), the animal population was sorted into groups, taking into account the genotype by the loci of the DGAT1 gene. The conducted studies have shown that in Tatarstan-type cows after the first lactation, a significant amount of the mass fraction of fat in milk was noted in cows with the DGAT1/АA genotype of the gene in comparison with peers of the DGAT1/АK genotype, the differences in other indicators of milk productivity were minimal. Also, among the first heifers of the Tatarstan type, the values of milk productivity indicators (milk yield, amount of milk fat and protein) are slightly higher in cows with the DGAT1/АA genotype of linear belonging to the Holstein breed, namely R. Sovering. Some attention in terms of conducting breeding work to increase the mass fraction of fat in milk is paid to individuals with the DGAT1/АK genotype of the W. Ideal and R. Sovering lines.