EVALUATION OF THE DAIRY COWS LIFE EXPECTANCY USING RED BLOOD CELL ANTIGENS OF THE B-SYSTEM OF BLOOD GROUPS

Abstract

Reduction of times of productive use of dairy cows in the conditions of modern technology of their keeping and feeding is the basis for analyzing the causes of early morbidity of the animals. One of the spheres of finding a solution for this problem is the search for genetic factors of productive longevity with the use of erythrocytic antigen-markers the B-system blood type. On the basis of the retrospective analysis the main reasons were found for animal morbidity of the Ayrshire breed in the breeding farms of Karelia. Using methods of cluster, factor and discriminating analysis, the population of cows (441 species) was reliably divided according to a number of indicators (longevity of life, productivity, live mass and the age of first calving) into three groups. The animals of the first cluster are of the greatest interest, where the longevity is 21 % higher than average, and the third, where this indicator is 27 % lower. At the same time, in each cluster frequency of alleles of EAB-system: in the first one the most widespread were the alleles BYA’E’₃G’P’Q’, В₁I₁O₁P₁P’₁F’₂G’’, В₁I₁P₁A’₁G’’, B₂G₂O₁G’’, Y₂A’₂, in the third one – B₁Y₂E’₃G’G’’, B₂G₂O₁Q’I’’ and P₁A’₁G’G’’. Distribution of animals according to the most frequent alleles showed that the values of longevity exceeding the single sample mean were found in the following groups: В₁I₁O₁P₁P’₁F’₂G’’, В₁I₁P₁A’₁G’’, ВYA’E’₃G’P’Q’, B₂G₂O₁G’’, PI’, P₂I’, Y₂A’₂ . Totally, it is 22,9 % of the livestock under study. Values under the average level are typical for the groups: B₁Y₂E’₃G’G’’, B₂G₂O₁Q’I’’, O_1, P₁A’₁G’G’’, Q, A’_1, A’₁E’₁ and A’₁I’’, which covers 56, 9 % of the livestock. Immunogenotypic markers of high life expectancy in the researched stock: alleles В₁I₁P₁A’₁G’’, B₂G₂O₁G’’, Y₂A’₂ were more frequent in the first cluster and were characterized by the maximal values of this indicator. On the contrary, alleles B₁Y₂E’₃G’G’’, B₂G₂O₁Q’I’’, P₁A’₁G’G’’ were widespread in the third cluster and the life expectancy of animal-carriers was the lowest.