The article says that all over the world, dairy livestock is used for dairy production. They use such breeds as a black-mottled breed, Holstein, Dutch ones. Breeding livestock differs in economically useful qualities depending on the climatic and ecological-forage conditions of the breeding zone, and the gene pool of breed resources. The widespread and long-term use of the Holsteinisation, along with a positive effect, i.e., an increase in milk yield, revealed problems associated with a decrease in the reproductive functions of the livestock. The aim of the work is to study the milk yield of the Holsteinized black-mottled breed of the Ural type depending on the duration of the service period. The article notes a significant percentage of dairy cows with a service period of more than 200 days and 121-160 days. Dairy cows with a service period of up to 120 days turned out to be 32%, taking into account the presence of dairy cows with optimal insemination period of only 19%. This indicates a decrease in reproductive functions in the Holsteinized black-mottled breed of the Ural type. The change in milk yield per three lactation depending on the duration of the service period is mainly determined by the individual characteristics of dairy cows and but not on the service period. Dairy cows with a service period of 103 days have the highest milk yield indicators. Dairy cows of other groups with other duration of the service periods had milk yield by 209 - 656 kg, or 1.96 - 6.15% less. The difference was not reliable due to the significant variation in milk yield within the groups. The duration of the service period does not affect the quality indicators of milk. The optimal duration of the service period for livestock breeding, namely the Holsteinized black- mottled breed of the Ural type is considered to be 81-120 days. An increase in the duration of the service period does not lead to an increase in milk yield, but affects the duration of productive longevity of dairy cows.

The article is based on the relevance of the development and production of specialized food products for nutrition of athletes, aimed at solving the problem of maintaining the appropriate physical condition of the population engaged in sports, fitness in a healthy lifestyle. As a result of theoretical and experimental researches the scientific concept of creation of fermented specialized food products on a dairy basis for sports nutrition is formulated, the structural and logistic scheme of realization of scientific and methodical principles of creation of these technologies is developed. Biotechnologies and recipes of specialized food products for sports nutrition have been developed. The biological and energetic value of diets with the use of specialized foodstuffs is determined. For practical realization of results of analytical and experimental researches normative and technical documentation for manufacture of new products which have been tested in industrial conditions of the operating enterprises of milk branch are developed. The technologies of all products are highly appreciated by consumers who are effectively engaged in sports and fitness.

The article suggests that one of the most widespread dairy breeds in the world is the Holstein breed; and the black-mottled breed in the Russian Federation. This breed has been improving during the past four decades by interbreeding it with the best one, the Holstein breed. A large set of the Holsteinized black-mottled livestock of the high thoroughbred cows of the Holstein breed has been produced. The aim of the work is to study the effect of age on the dynamics of dairy efficiency of the Holsteinized cows depending on the breeding line. At present, the dairy herd of the farm actually consists of cows of three breeding lines, Reflection Sovering 198998, Vis Back Ideal 1013415, Montvik Chieftain 95679. The rest breeds are not developing due to the absence of breeding valuable breeding bulls. It was found that the Reflection Sovering breeding line 198998 has that the highest milk yield during the sixth lactation, and then there is a decrease in milk yield. The article considers that the milk yield changes with age, starting from the first lactation, increasing during the second lactation and then it is gradually decreasing in productivity to the fifth one. The regularity of the increase in milk yield of mature cows during the third and fourth lactation is not confirmed of the dairy cows of this breeding line. It can be explained by the intensity of herb replacement, when it accumulates a significant amount of nutrients in the body. That is why, they can be used during the first and the second lactations without restoring nutrients in further. Dairy cows of the Vis Back Ideal 1013415 breeding line have a gradual increase in milk yield, starting from the first to the fourth lactation, by 52, 292, 300 kg or by 0.5; 2.8% and 2.8%, respectively. Further, there is a decrease in dairy efficiency. At reaching physiological maturity they have a natural increase in dairy efficiency. The same tendency is observed with cows of the Montvik Chieftein 95679 breeding line.

The increase in the productivity of cows is inseparably linked with the intensification of selection work with dairy cattle. All over the world, dairy cattle are used to obtain milk, including such related ones as black-and-white, Holstein, Dutch, which differ in economically useful qualities depending on the climatic and ecological-forage conditions of the breeding zone, and the gene pool of breed resources. Animal perfection is achieved by selecting the best males and females for reproduction and individual selection. The transmission of genes from generation to generation is carried out from father to son, from mother to son, from father to daughter, from mother to daughter. The rate of genetic improvement in dairy cattle populations depends on the efficiency of the assessment, selection and use of these groups of animals. Currently, the farm uses the daughters of sire bulls belonging to 3 Holstein lines. Several breeding bulls are used in each line. So, at present, the farm uses 17 bulls-sires of the Vis Back Aydial 1013415 line, 10 bulls of the Reflection Sovering 198998 line and 3 bulls of the Montvik Chief 95679 line, but the daughters of not all breeding bulls are already used in the herd. The belonging of cows to a certain line reliably at a high level of reliability influences the indicators of milk productivity. The decrease in milk yield in cows of the Montvik Chieftain 95679 line is accompanied by an improvement in the quality indicators of milk, namely, MJ in milk. Daughters of bulls-producers of a certain line differ in their productive qualities. The best indicators were found in the groups of daughters of sire bulls: Emen 105018721 and Pilot 63811814 (Reflection Sovering line 198998); Reverse 2708 (Montvik Chieftain line 95679); Tek 69052876 and Fennek 4241542328 (Vis Back Aydial line 1013415).