Association of HindIII-polymorphism in kappa-casein gene with milk, fat and protein yield in holstein cattle*

Abstract

The aim of the paper was to evaluate the effect of genetic polymorphism of kappa-casein on the milk production in Holstein cattle. A total 210 cows of Holstein cattle were use in this study. On the basis of PCR-RFLP analyses we established genotype structure of cattle population and calculated allelic frequencies. In Holstein cattle population was detected all three genotypes – AA (69.52%), AB (27.62%) and BB (2.86%). The frequency of allele A was 83.33% and allele B was 16.67%. Effectiveness of allele incidence and genetic diversity was evaluated with following parameters: theoretical heterozygosity (Heexp), experimental heterozygosity (Heobs), polymorphism information content (PIC), expected homozygosity (E), effective number of alleles (ENA), level of possible variability realization (V%). The Holstein cattle kept in Slovak Republic exhibit high value of homozygosity and low values of polymorphism information content, effective number of alleles and level of possible variability realization. The effect of polymorphism of CSN3 gene on average breeding values for milk production traits as the yield of milk, fat and protein in kilograms as well as contents of fat and protein in percentages was detected using by the packed SAS 9.3 of SAS Enterprise Guide 5.1. We detected statistical significant difference between genotypes only at an average breeding value for the percentage of protein in milk during assessment the variability of observed traits in depending on polymorphism of CSN3 gene. For other breeding values the impact of individual genotypes CSN3 gene on their variability was not observed.