Connection between gene markers with milk production traits of Ukrainian dairy cows

The purpose of this study was to obtain information on the genotyping of cows of Ukrainian dairy breeds for the presented loci capa-casein gene (CSN3), thyroglobulin (TG-5) gene, leptin (LEP), pituitary-specific transcription factor (Pit-1), and beta-lactoglobulin (BLG) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and to test their association with milk production. The influence of the genotype on milk yield, fat and protein content in the milk of cows of Ukrainian selection has been established. The highest levels of milk productivity traits were expected from animals with the CT genotype for the LEP gene, AA for the CSN3 gene, CC for the TG5 gene, and AA and BB for the Pit-1 gene. But at the same time, milk obtained from cows with CSN3 BB genotype were characterized by the best cheese suitability. The effect of the homo- or heterozygous state of BLG on the signs of milk production was less noticeable, and the homozygous TT genotype for the TG5 gene was not found in any of the studied breeds. The results obtained can be used in the practical work of breeding farms along with traditional methods of selection, control and preservation of the genetic diversity of specific herds at an optimal level.