Duration and efficiency of lifetime use of cows of different genotypes according to beta-casein

Abstract

The article examines the peculiarities of the duration and efficiency of the use of cows depending on the genotype of the cows for the beta-casein gene. Genotyping of 136 cows of Sumy intrabreed type of Ukrainian black and white dairy breed and Ukrainian brown dairy breed, which are kept in the breeding farms of the State Enterprise «Research Farm of the Institute of Agriculture of Northern East of NAAS» of Sumy district of Sumy region, was carried out. In order to determine the polymorphism of the beta-casein gene, genetic studies were carried out in the laboratory of the Institute of Physiology n.a. Bogomolets of NAS with the help of molecular biological analysis of allele recognition by polymerase chain reaction (PCR) in real time. The duration and efficiency of the use of cows was determined with the help of generally accepted methods, using the electronic database of SUMS «Orsek» of breeding farms. An interbreed differentiation according to the share of abandoned animals was established. Among the genotyped cows of Ukrainian black and white dairy breed - 37 % were eliminated, and 46 % - of Ukrainian brown dairy breed. Most of the animals that were eliminated among Ukrainian black and white dairy breed were animals with the A2A2 genotype (47 %), and Ukrainian brown dairy breed - A1A1 (67 %). Cows of Ukrainian black and white dairy breed with the A1A2 genotype had a longer average period of life, economic use and lactation compared to animals of other genotypes. In terms of lifetime productivity, cows with the A2A2 genotype prevailed. The average values of milk yield per day of life, economic use and lactation were higher in animals with the A1A1 genotype. At the same time, the difference was not statistically significant. On the contrary, cows of Ukrainian brown dairy breed with the A2A2 genotype had a longer average period of life, economic use and lactation. They prevailed in indicators of lifetime productivity, milk yield per day of life, per day of economic use and lactation of animals with other genotypes, with a statistically insignificant difference. Accordingly, the formation of a herd of animals with the A2A2 genotype for beta-casein will allow to preserve the indicators of the duration and efficiency of the lifelong use of Ukrainian black and white and brown dairy breed cows. The obtained results are preliminary, which is due to the small number of experimental livestock. Therefore, we believe that research should be continued. Key words: genotype, beta-casein, life expectancy, lifetime productivity, coefficient of economic use.