K-casein gene polymorphism and milk technological parameters in Simmental cows from the Altai Republic

At four cattle farms, a frequency of AA, AB and BB genotype on k-casein gene was tested among 394 Simmental cows of the second calving and older. The desired BB genotype frequency was shown to vary from 7.2 to 16.7 %. In milk of the cows of that genotype, protein content was up to 0.06-0.43 % as compared with other individuals. This milk was also heat stable and had the better indices in alcohol test and the higher technological properties for cheese making. Moreover, the milk of Simmental cows was enriched with potassium, iron, manganese, and zinc as compared to the milk of cows in the Black-and-White to Golshtin crosses.