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In 2002, a new Ural type of black-and-white breed was officially registered. Animals of this type have high productivity indicators, but at the same time there is a decrease in the productive longevity of the breeding stock. The conjugacy of milk yield for lactation is established, which allows for the first lactation to carry out selection fory milk yield. The relationship of milk yield for the first lactation weakens with the age of the animals and becomes negative for the fifth lactation. The conjugacy of such characteristics as milk yield per lactation and fat mass fraction in milk varies both by lactation and relative to milk yield per lactation. The conjugacy between milk yield and protein in milk for lactation was negative with fluctuations from low to medium-negative. For 5 lactation, there is a high positive relationship between milk yield for the first lactation and protein mass fraction in milk for 5 lactation. There are fluctuations in the correlation coefficients for fat mass fraction in milk for lactations, the conjugation of the trait with each other remains positive in the period from the first to the 4 lactation, excluding the correlation coefficient of this indicator between 1 and 5 lactation.

In the Sverdlovsk region, in herds of Holstein black-and-white cattle of the Ural type, up to 98% of cows are descended from bull producers of foreign selection. Assessment of the influence of a bull producer on the productive qualities of daughters is relevant and of practical importance, especially in conditions of increased blood in the Holstein breed. The daughters of the breeding bull Gavano had the highest indicators in terms of milk production, the daughters of the breeding bull Das were in second place. It should be noted that the milk yield for 305 days of lactation in all studied animals was within the range of 6583 (daughter of bull Cassio) - 8106 (daughter of bull Gavano) kg, which indicates a high potential for productivity in the cows of this herd. The superiority of the daughters of bull Gavano in milk yield ranged from 445 to 1523 kg or 5.5 - 18.8% and was reliable in favor of the former (P≤0.05 - P≤0.01). The highest rates for fat mass fraction in milk were found in the daughters of bull De-Su. 4,0 and 4,01% of fat was in milk of cows-daughters of the Sayan, Mers and Cassio bulls. In terms of protein mass fraction in milk, cows differed from bull De-Su for the worse. In the milk of cows-daughters of other bull producers the protein mass fraction was in the range of 3.13-3.17%. The yield of milk fat and milk protein was more influenced by milk yield in 305 days of lactation. Most of the nutrients were obtained from the milk of the cows-daughters of bull Gavano. The daughters of bull Sayan were in second place, only slightly inferior to them were the daughters of bulls Das and De-Su. Less nutrients were obtained with milk from the daughters of bull Cassio. All cows had a dairy production direction, as evidenced by a high milk yield ratio from 1186 to 1432 kg of milk per 100 kg of live weight of a cow. The farm uses daughter cows from Holstein bull producers with a high genetic potential for productivity.

Provision of the population with a sufficient amount of domestically produced food, including milk and dairy products, is directly related to advances in breeding of dairy cattle as the main supplier of raw materials for dairy processing enterprises. Along with increased requirements for the quality of milk – raw material in production of dairy products – the focus is placed on its technological properties, namely the possibility of its effective use for processing into certain products: fermented milk, cheese, butter, etc. It is known that milk is affected by many factors, including the season of the year, which impacts not only supply of raw materials to the dairy industry but also its quality. The study aimed to investigate the impact of the season of the year on raw milk intended for processing into various dairy products. The study revealed that sensory properties of milk met the requirements of the regulatory documents. The milk color changed depending on the season of the year. A more intense yellowish hue could be observed in summer and autumn milk, which is related to the carotene content in feed. The highest content of dry solids, milk solids-not-fat, fat and protein in milk was found in winter, while in summer these indicators were lowest. In spring, mechanical contamination of milk increased up to group 2. In general, the bulk of the milk was of the highest grade. The study of rennet coagulation of milk showed the superiority of milk produced in spring, as evidenced by a phase of coagulation of milk, which was shorter by 0’05“–2’35” (P <0.001). A clot formed faster in the presence of rennet in summer milk. Thermal stability of milk was high throughout the year.

The article assumes that in the Sverdlovsk region, breeding bulls of the Holstein breed with high efficiency according to their maternal ancestors were used on the breeding stock of the black-mottled breed of the Ural spawn. Animals of this type are of high efficiency. The efficiency evaluation of Ural type cows is urgent. The aim of the work is to evaluate the efficiency of the new genotype cows in terms of their milk yield qualities. It has been found that dairy cows show high milk yields. In accordance with physiological laws, they increase until the fourth lactation, and then gradually go down. The first insemination of replacement heifers on the farm is carried out at the age of 18-19 months with a live weight of over 400 kg. This makes it possible to breed healthy strong animals capable of breeding for a long time and having high milk yield. The maximum milk yield is from 21 kg to 1986 kg (from 0.2% to 35.3%); it is more than the actual one. The farm has reserves for increasing milk yield due to measures for the milk efficiency of the first-year heifers and other cows. It will significantly increase the milk yield in the third and further lactation. The authors calculated the life-long milk yield. It turned out that in fact, 84,450 kg of milk can be obtained from a dairy cow during 10 lactations. The efficiency potential of lifetime productivity, based on the maximum milk yield per lactation, was 7077 kg or 8.4% higher. The predicted potential shows that 104 101 kg of milk can be obtained from a dairy cow during 11 lactations. The efficiency fluctuations by lactation are significant; and from the first to the 5th lactation they exceed 150% of the minimum milk yield of dairy cows to the maximum in the same lactation. So, it is possible to make a conclusion about the great changeability of this feature in the herd and the great possibilities of selection at carrying out selection and breeding work on the farm.

Modern industrial milk processing based on high-tech processes has high demands to the quality of milk used as raw material for the production of a wide range of dairy products. Seasonality of milk production remains a significant problem for dairy cattle breeding. In some seasons, the supply of milk of optimal quality is rather unstable. The purpose of the work was to study the influence of season on the technological properties of milk during its processing into dairy products. As a result of research, it was found that the organoleptic properties of milk met the requirements of regulatory documents. The milk color changed with the seasons. A more intense yellowish tint in the milk color was noted in summer and autumn, which is associated with the carotene content in feed. The highest content of dry matter, SNF, fat and protein in milk was observed in winter, while in summer these values were the lowest. In the spring period, there is an increase in the mechanical contamination of milk up to group 2. In general, the bulk of milk has primary quality. The coagulation phase in cows’ milk was shorter in spring than in other seasons of the year (P <0.001) by 0’05 “- 2’35”, and it was longer in milk obtained in winter. The best speed to clot under the influence of rennet was the milk of cows in summer. Evaluation of milk for thermal stability, depending on the season of the year, showed that it has high thermal stability and can be used for processing into products with a high temperature of pasteurization and sterilization.

Holsteinized black-and-white cattle are used for milk production. The genealogical structure of the herd is represented by animals from the following genealogical lines: Vis Back Ideal 1013485, Reflection Sovering 198998, Montwick Cheiftain 95679, Pabst Governor 882933 and Annas Adema 30587. Animals of these types feature high milk productivity indices. In particular, the cows of all the researched lines have high milk productivity indices - more than 9,000 kg of milk per lactation. The highest milk yields are achieved by cows of the Montwick Cheiftain 95679 line. The yields are 16-339 kg higher than ones of the animals from the Annas Adema 30587 and Pabst Governor 882933 lines, respectively. According to the quality indices of milk, cows of all lines exceed the requirements of the breed standard. Data on amount of milk fat confirms the level of breeding value of the cattle breeding stock used in the farm. They exceed the breed standard in terms of milk fat yield by more than 2 times. The highest coefficient of the cows’ biological efficiency was recorded in the cows groups of Annas Adema 30587 and Montwick Cheiftain 95679 lines, and the biological full-value was confirmed for the Montwick Cheiftain 95679 and Pabst Governor 882933 lines.

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