CSN2 LOCUS POLYMORPHISM IN THE CATTLE OF THE JERSEY BREED
A2 milk is getting more and more popular in different countries of the world. Using PCR / RFLP methods, we have established the frequency of occurrence of the economically valuable A2A2 genotype in a group of Jersey cattle belonging to one of the Russian farms. The frequency of occurrence of the desired A2A2 genotype in the cattle of the Jersey breed was 0.60, the A2 allele was found with a frequency of 0.76. Compared with cattle of Holstein and Ayrshire breeds, Jersey cattle have a significantly higher frequency of occurrence of the A2A2 genotype (on average, it is 35-40 % higher).