Chromosomal mutations in high-yield Holstein cows
The results of the research of somatic chromosomal instability: aneuploidy and polyploidy in the blood cells of high-yield Holstein cows with the productivity of more than 9000 kg have been presented in the article. The research was conducted in JSC Vaganovo, Promyshlennovsky District, Kemerovo Region on the population of Holstein cows. Sample preparation was carried out according to P. Moorhead et al. Samples were stained using the Romanowsky-Giemsa method. The authors studied 6068 metaphase plates in a group of 30 healthy animals. Aneuploidy was counted according to the practice of N.P. Bochkov et al. The authors also analysed the ecological situation in the area of keeping and breeding cattle. Studies of soil, fodder, organs and tissues in farm animals of different species confirm that heavy metal and chemical pollutants are not contaminated in Western Siberia, and their levels are within sanitary norms. Therefore, the ecological situation in the study area should be considered safe. The study shows that the frequency of polyploidy was 0.59% in the studied sample. Tetraploidy, triploidy, and hexaploidy rates were 0.33; 0.18 and 0.06, respectively, the frequency of true hypoploidy was 0.73, and the number of diploid cells was 84.7%. The data obtained can be tentatively applied as average values and can also be used to evaluate the interior of the animals.