Relationship between Milk Protein Polymorphism and Selected Cows’ Reproductive Indices

This research sought to determine the effect of selected milk protein polymorphisms on reproduction parameters 598 black and white Polish Holstein–Friesian cattle. The analyzed genes were kappa-casein (CSN3) beta-lactoglobulin (BLG). following reproductive indexes selected: age at first calving, interpregnancy period, calving interval, insemination index. influence identified genotypes course parturition in cows was also analyzed. Source data collected for each cow from beginning herd life its culling or end third lactation. Data amount semen portions artificial (insemination index), interval collected. A contingency analysis performed through tables using a Pearson’s chi-squared test CSN3 BLG genotype. results show that BB genotype gene associated with most favorable values indicators. In case significantly more than those other (p ≤ 0.05). No polymorphism indices observed. On hand, significant statistical differences obtained between AA genotypes. did not cows. To conclude, is performance examined herd.