Polymorphism of the CSN3 gene and its association with the blood biochemical profile in Holstein cattle

Abstract

Molecular genetic markers, such as the polymorphism of the kappa-casein gene (CSN3), are a important tool for increasing the efficiency of dairy cattle breeding. The aim of this study was to investigate CSN3 polymorphism in a Holstein cattle population and to assess its associations with blood biochemical parameters reflecting the animals’ metabolic status. In the studied herd (146 animals), allele (A — 0,651, B — 0,349) and genotype frequencies were determined using the PCR-RFLP method: AB (47,9 %; 70 animals), AA (41,1 %; 60 animals), and BB (11,0 %; 16 animals). The results of the biochemical analysis for 12 blood serum parameters were statistically processed using t-test Student in the context of the identified genotypes. Significant associations of CSN3 polymorphism with the biochemical profile were revealed. Carriers of the B allele, especially those with the BB genotype, were characterized by a significantly higher level of protein metabolism indicators (total protein, albumin, urea, creatinine) and activity of enzymes from the classes of aminotransferases (AST, ALT) and hydrolases (alkaline phosphatase), as well as lower concentrations of bilirubin and glucose compared to animals with the AA genotype. The obtained data indicate more intensive metabolism and efficient liver function in cows with the B allele. The results confirm the pleiotropic effect of the CSN3 gene, linking the genetic variant not only to milk quality but also to the body’s metabolic profile. This substantiates the feasibility of using this gene as a marker for the comprehensive assessment and prediction of metabolic adaptation in Holstein cattle breeding programs. The work was carried out according to a state assignment, registration number 125031003428-9