Polymorphism of k-casein and β-lactoglobuline in Simmental cattle in Serbia

The objective of this study was to determine the frequency of the κ-casein and β-lactoglobulin genotypes in the Simmental cattle in Serbia and compare it with the frequency according to the Hardy-Weinberg equilibrium law. Blood samples were taken from a total of 157 cows of the Simmental breed in Toplica and Rasina districts. Of the 157 cows included in this study, the AA κ-casein genotype was found in 53 cows, which makes a frequency of 33.80%, the genotype in 81 cows or 51.60% and the BB genotype in 23 cows or 14.60%. The allelic frequency A was 59.60%, while allele B had a frequency of 40.40%. In regard to the frequency of genotypes and β-lactoglobulin alleles for the total studied population of cows obtained for AA, and BB genotypes for β-lactoglobulin, was 33.10%, 49.70% and 17.20%, respectively, which means that 52 animals had genotype AA, 78 genotype and 27 genotype BB. The frequency of alleles A and B resulting from the incidence of genotypes was 58.00% for allele A and 42.00% for allele B. The specified frequencies for both protein fractions statistically differed significantly from the frequency according to the Hardy-Weinberg equilibrium law, which confirmed the absence of equilibrium in the examined population. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31030