KAPPA - CASEIN GENE POLYMORPHISM (CSN3) AND ITS EFFECT ON MILK PRODUCTION TRAITS

Abstract

The aim of this study was to evaluate the relationship between the polymorphism in the kappa - casein gene and milk production traits in crosses of Simmental and Holstein cattle breeds. A total of 80 hair roots samples were used to investigate how CSN3 gene polymorphisms affect milk production traits. The polymorphism of kappa - casein gene on bovine chromosome 6 was genotyped by using the polymerase chain restriction fragment length polymorphism. The effects of polymorphisms were analysed using SAS 9.1 software. Digestion of PCR products with restriction enzyme HindII revealed two alleles: allele A gave one fragments, 443 bp in length and allele B gave two fragments of 348 and 95 bp. The predominant allele was A with observed frequency 0.76. In population were detected all three genotypes AA, AB and BB.  The most frequent genotype was AA with frequency 0.575. Results from the statistical association analysis between CSN3 genotypes and milk production parameters – milk, protein and fat yield (kg) in standard length of lactation were no significant.

Key words: dairy cattle, kappa - casein gene, milk production, polymorphism