Polymorphism of κ-casein and β-lactoglobulin genes in Busha and Holstein Friesian dairy cows in Serbia

The aim of this study was to determine the distribution of kappa-casein (kappa-CN) and beta-lactoglobulin (beta-Lg) genotypes in the autochtonous (Busha) and dairy (Holstein-Friesian, HF) cattle breeds with PCR-RFLP (polymerase chain reaction - restriction fragment length polymorphism). For the amplification of kappa-CN and beta-Lg gene fragments specific primers were used. After digestion with specific endonucleases genotypes were determined for both genes in 18 Busha and 19 HF cows. The results showed that kappa-CN gene was represented with the AA genotype in 31.58 % HF cows, AB in 52.63 % cows, whilst the genotype BB was found in 15.79 % cows only. Among the examined Busha cattle 44.44 % cows had AA genotype and 55.56 % genotype AB for kappa-CN. As for beta-Lg gene in HF breed, AA genotype was found in 26.31 % cows, AB in 63.16 % and BB in 10.53 % cows. In Busha cows the following genotypes were established for beta-Lg gene: AA in 44.44 % cows and AB in 55.56 %, whilst BB genotype was not found. These results indicate that Busha cows had a higher presence of A allelic forms of both genes (k-CN and beta-lactoglobulin) than HF cows.