The article presents data on the age dynamics of changes in the level of dairy productivity of cows. As a result of the research, the increase in milk yield and the increase amount of milk fat and protein with age of animals was established. The age dependence of qualitative indicators of milk production wasn’t revealed. It was noted that the level of milk productivity of cows in all age periods was higher than the requirements of the first class standard of black-motley breed. An average positive correlation was found between age and milk yield. It was revealed that the productivity of cows is largely determined by their linear affiliation. When analyzing the age-related changes in the reproductive capacity of cows was revealed that the duration of the service period decreases with the age of the animals. When analyzing the age-related changes in the reproductive capacity of cows was revealed that the duration of the service-period decreases with the age of the animals. The duration period between the calves of the average for the cows was optimal, while its reduction with age was observed. It’s noted that as the age of cows increases, the number of inseminations for fertilization increases.

Bulletin the National academy of sciences of the Republic of Kazakhstan 4 Г л а в н ы й р е д а к т о р д. х. н., проф. академик НАН РК

During the day protein mass fraction and fat mass fraction in mares’ milk changes in different ways. The variability of fat content in mare’s milk reaches 60% within 24 hours. Several experiments, including the milking of mares continuously during the day, were conducted to explain the nature of this phenomenon. Differences in the variability of fat and protein contents in the mares’ milk during the day and various way of secretion of the milk components from udder’s secretory cells were explained by the authors in this scientific article. The protein is secreted due to merocrine secretion, and fat secretion mainly occurs due to apocrine secretion. Reduction of fat content in the mares’ milk is caused by the significant increase of milk yield in the early morning, when secretion of synthesized fat slows down. When milk yield is reduced, the secretion of stored fat is increased, which also increases the fat content in milk. It was found that in the morning milk yield of mares is higher than at night by 16.39 %. It was also found that during the day protein mass fraction is higher than it is at night by 5.24 %. The fat content in the mares’ milk during the day is higher than it is at night by 12.24 %. The ratio of daily milk yield and fat content was amounted to 0.22, of daily milk yield and protein mass fraction was + 0.44, and of fat mass fraction and protein mass fraction was + 0.47.

The presented work is the result of studies of the influence of the type of higher nervous activity on the dairy productivity of mares of the Russian heavy draft horse breed on stationary koumiss farms. To determine the types of higher nervous activity, a motor-food technique developed by the All-Russian Research Institute of Horse Breeding was used. The milk yield was counted at animals for the first lactation, for the highest lactation, on average for one lactation and a lifelong milk yield of mares. The milk yield on average for lactation is almost the same in mares with a strong balanced mobile type and with a strong unbalanced type of higher nervous activity. Animals of a weak type and a strong balanced inert type of higher nervous activity lag behind them in this indicator by 11-13%. Horses with a strong balanced mobile type, a strong unbalanced type and a weak type of higher nervous activity are most suitable for the duration of economic use and lifelong milk production. The mares with a strong balanced inert type of higher nervous activity are the least productive in terms of duration of economic use and lifelong milk yield on koumiss farms.

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