Genetic markers associated with milk and meat productivity of cows

Genetic markers associated with milk and meat productivity in cows were analyzed. Using the polymerase chain reaction (PCR) method followed by restriction fragment analysis, polymorphisms in the genes for κ-casein (CSN3), β-lactoglobulin (BLG), diacylglycerol O-acyltransferase 1 (DGAT1), pituitary transcription factor (PIT1), thyroglobulin (TG5), and growth hormone (GH) were determined in animals of the Brown Carpathian breed. The genetic study was conducted on 30 cows kept in the private sector of the Transcarpathian region. The distribution of allele frequencies and genotypes of the studied genes was determined. In the studied sample of animals, the most common alleles were A and genotype AA of the CSN3 gene (0.64 and 0.43, respectively), allele B and genotype AB of the BLG gene (0.58 and 0.43, respectively), allele B and genotype BB of the PIT1 gene (0.82 and 0.68, respectively), allele K and genotype KA of the DGAT1 gene (0.58 and 0.84, respectively), allele L and genotype LL of the GH gene (0.64 and 0.5, respectively), allele T and genotype TT of the TG5 gene (0.66 and 0.61, respectively). High levels of homozygosity were observed at the studied loci, ranged from 17% in DGAT1 to 90% in TG5. This indicates that the number of effectively functioning alleles in the studied population is lower than the possible maximum, resulting in reduced genetic diversity.