ON THE CHANGE IN THE CONTENT OF THE MASS FRACTION OF PROTEIN IN BLACK PIED COWS WITH DIFFERENT HEREDITARY TYPES

Today, cattle breeding involves highly productive animals. Within the breed and each farm, there are cows of differentgenotypes with different milk yield and with different content of the mass fraction of protein in milk. Studies show that with ahigh level of dairy herd, the possibilities of breeding highly productive first-born heifers from mothers of different ages are notthe same. The intensification of dairy cattle breeding is impossible without the creation of highly productive animals capableof not only showing high productivity indicators for the first lactation but also increasing it with age, realizing the geneticpotential of dairy productivity characteristic of the Holstein breed [7], [8], [2]. This study and its practical significance lie inidentifying the desirable compatibility of high milk yields with a high content of the mass fraction of protein in milk in blackpied cows [1], [3], [5], [7]. It is important to substantiate and define biological types. The study identifies hereditary types ofprotein-milk content and examines economically useful traits and morphological indicators of blood in cows with differenthereditary types. A modern approach to the assessment of protein-milk content will expand the possibilities of selecting cowsof desirable hereditary types [4], [6], [10]. The hereditary types of cows presented in the article (progressive, regressive, stableand unstable) show that an early assessment in highly productive cows will eliminate the use of undesirable types [6].As theresearch results have shown, if biological types are distinguished among cows according to the compatibility of high milk yieldand the content of high values of the mass fraction of protein, it is possible to breed more productive animals that meet modernrequirements of production technology [9], [6].