GENETIC HISTORY AND VALUE OF THE GENE POOL APPEARING HOLMOGOSKY BREED
Historical, population-genetic and zootechnical aspects of the gene pool formation of the oldest domestic Kholmogory breed are discussed. The allelic structure and gene frequency analysis for the loci controlling the synthesis of milk proteins and antigens of the blood groups revealed the original structure of the allele fund and the interlocus combinations of genes. Judging by the haplotypes of the Y chromosome, the breed is related to the Western European dairy cattle of the black pied root. On the maternal side, it has common origin with the Finnish native hornless breeds and the Yaroslavl cattle. The results of the genome-wide Association studies conducted using 35874 polymorphic SNPs showed clear differentiation of the Kholmogory cattle from four other domestic breeds (Yaroslavl, Bestuzhev, Red Gorvatov, Kostroma breeds), and from the Holstein breed. The revealed similarity of Kholmogory cattle with the Yaroslavl breed (Q=6,4%) indicates their common historical origin from the Northern Great Russian cattle. The use of the Dutch cattle on different stages of the Kholmogory breed formation is reflected in the presence of the genetic component specific to the Holstein breed in the structure (Q=2,7%). Comparative evaluation of the Kholmogory, Holstein, Ayrshire, black pied and Yaroslavl breeds by the level of milk productivity for the last completed 305-day lactation and the total amount of completed lactations, as well as demographic indicators and indices of lifetime productivity showed that the Kholmogory breed is inferior to the Holstein, Ayrshire and black pied breeds in the yield of milk and production of milk fat for the last complete 305-day lactation. It is superior to all of the compared breeds in milk productivity for the total amount of completed lactations. The Kholmagory breed is inferior only to the Ayrshire breed counting upon one month of life and a hundredweight of live weight. It is shown that the Kholmogory breed surpasses the Holstein breed in a number of dietary and technological qualities of milk. The measures on preservation of domestic breeds are offered.