Factors and their influence on the indicators of milk productivity of first-born of Ukrainian dairy breeds

Abstract

The article examines the influence of genotypic factors on the formation of milk productivity indicators in first-born cows of various breeds. Genotyping of 744 cows of Ukrainian Brown Dairy, Ukrainian RedAnd White, Ukrainian Black-and-White Dairy breeds and Sumy inbred type of Ukrainian Black-and-White dairy breed, which are kept in breeding farms of State Enterprise "Experimental Farm of Institute of Agriculture of Northern East of NAAS" of Sumy district of Sumy Region and PRAE Ichnyanske and PRAE Khliborob of Chernihiv region. In order to determine the polymorphism of the beta-casein gene, genetic studies were carried out in the laboratory of Institute of Physiology named after Bogomolets of NAS with the help of molecular biological analysis of allele recognition by polymerase chain reaction (PCR) in real time. The study of milk productivity indicators was carried out with the help of generally accepted methods, using the electronic database of SUMS "Orsek". The influence of genotypic factors was determined based on the results of one-factor variance analysis. Between animals of different breeds, there is a significant difference in the influence of genotypic factors on indicators of milk productivity. Linear belonging had a statistically significant effect on milk yield and the content of fat and protein in milk in animals of the Ukrainian black-and-white and redand-white dairy breeds. Whereas in cows of Ukrainian brown dairy breed - only on the amount of milk yield. In first-borns of Sumy intrabreed type, linear belonging did not have a statistically significant effect on the studied indicators. Father's origin has a much greater influence (ή2,=22-62 %). The genotype of the animal according to beta-casein actually does not have a reliable effect on the indicators of milk productivity. However, in animals of Ukrainian red-and-white dairy breed and Sumy inbred type of Ukrainian black-and-white dairy breed, it reliably influenced the formation of milk yield and fat content in milk. Therefore, with the aim of forming the desired value of milk productivity traits in first-born cows, the primary task is to carry out the selection of breeders assessed for the quality of the offspring of the corresponding lineal affiliation. Key words: genotype, beta-casein, influence, milk productivity, breed