The increase in the duration of productive longevity of highly productive cows remains a problematic issue and in recent years has attracted increasing attention of domestic and foreign scientists. Accelerated herd turnover and significant premature retirement of Holstein animals in herds may subsequently have negative economic and biological consequences. The analysis of the lifetime productivity of the Holstein cattle of European breeding and their daughters under the conditions of industrial milk production technology has been carried out; the reasons for the culling of animals due to diseases have been clarified. It is established that under the conditions of an industrial complex the period of productive use of Holstein cattle is sharply reduced. The duration of the lactation period in cows-daughters compared with mothers significantly decreased by 463.6 days (by 32.5%) and amounted to only 2.5 lactations (P < 0.01). At the same time, lifelong milk yield was lower by 8427.1 kg (25.9%), and during life from them was received on one calf less. The main reasons for premature departure from the herd of imported animals were: a violation of reproductive capacity (25.6%) and postpartum complications (7.4%), diseases of the digestive system (22.3%), limbs (21.5%) and mastitis (6.6%). Excessive exploitation of animals led to a decrease in natural resistance, which manifested itself in an increase in the number of pathologies of reproductive organs (6.7%), digestive organs (5.5%) and mammary glands (8.5%) among the first-generation cows. Accelerated herd turnover as a result of premature retirement of highly productive cows, necessitates the search for rational ways to increase the natural resistance of the animal organism in conditions of industrial milk production technology aimed at prolonging their productive longevity.

In monitoring studies of recent years, global warming is reported. This is a significant problem for dairy farming in much of Europe, especially in the central and southern regions, as reported by numerous studies. Dairy cattle highly productive are extremely sensitive to hot temperatures; their consequence is health problems, a significant reduction in milk yield and milk quality. Unfortunately, heat stress remains an unrecognized problem for domestic cattle breeding, although the financial losses from its harmful influence in European are quite substantial. The aim of our work was to study the effect of high temperatures on milk yield of cows of Ukrainian Schwitz on one of the complexes of high-tech milk production. At the beginning of the research, we decided to test the hypothesis of increasing hot air temperatures in the warm period of the year compared with the long-term data. Then we studied how the milk of Schwitz breed varies during the hot season, depending on the magnitude of the maximum temperature values. According to the results of the study, it can be noted that the air temperature during the warm period of 2017 tended to increase (+0.6 ° С) in comparison with the long-term data. In August, the air temperature significantly exceeded the long-term data by +3 ° C (td = 2.89, P<0.05).The obtained results testify that in the conditions of the central region of Ukraine in the warm period of the year the probability of occurrence of heat stress in dairy cows is high. In the warm season of 2017, the period during which THI exceeded the comfortable value for dairy cows was 100 days. At the same time, a decrease in productivity per cow in the hot season may

Decrease in productive longevity of dairy cows in conditions of industrial dairy complexes causes another problem, which is connected with the timely replenishment of the herd with calves for replacement. Therefore, the cultivation of heifers has very great impact. Much attention is focused on early prediction of the future calves productivity for obtaining highly productive cows. At the same time, the growth rates and development in ontogenesis are studied very often, but blood values are rarely evaluated. In the literature available to us, there is little information about the relationship between calves' humoral and cellular immunity values with the future productivity of the cow. These indicators are traditionally used to characterize the immunobiological reactivity of an organism and the calves' health, and there is practically no information on their relationship to the productive longevity of a dairy cow. This is partly due to the difficulties associated with the duration of the research, since the cow must complete its productive life. A positive and reliable relationship is established between the immunobiological characteristics of calves' blood and their lifelong milk yield when they become a cow. The greatest correlation was noted between the milk productivity's indicators and bactericidal activity of blood serum (r = 0.63-0.69, P < 0.05). The relationship between cellular factors of body defense (phagocytic activity of neutrophils) and the immunoglobulins content of classes G and M with signs of milk productivity was less dense. It was, respectively, r = 0.31-0.41 and r = 0.58-0.63 (P < 0.05). This makes it possible to conclude that the studies conducted in this direction are promising, and assessing calves' immune status for predicting the yield of cow milk. The results obtained by us require further confirmation in a more significant number of animals.

The lifetime productivity of European Holstein cows and their offspring under conditions of industrial milk production technology was studied. It is established that the productive longevity of European Holstein cow offspring in the conditions of the industrial complex was reduced by 1.0 lactation (td = 5.6 or P≥ 0.999), an average of 2.6 lactations. The lifetime milk yield was lower by 20.9% (td = 2.6 or P≥0.99), and the yield of milk fat and protein by 23.0 (td = 3.3 or P≥ 0.999) and 24.1% (Td = 4.8 or P≥ 0.999). At the same time, the influence of origin on lifelong milk yield was 9.5% (P≥0.95), on fat content -22.7% (P≥0.999) and on milk protein -37.5% (P≥0.999). The variation coefficient (Cv = 12.1 ... 79.2%) of animal signs has a sufficient level for carrying out effective breeding work. Revealed high phenotypic and genotypic correlation coefficients between the indices of lifetime productivity (r = + 0.92 ... + 0.98) showed that the breeding of any signs will have a positive effect on others ones. The coefficients of productive qualities heredity (h2 = 0.18 ... 0.23), prove that breeding based on the lifetime productivity signs will have a positive effect on the progress in dairy cattle breeding. Evaluation of dairy cattle productive longevity has great scientific and practical importance. Studies were carried out on Holstein cows using the data of the dairy cattle management system "Orsek". Biometric processing was carried out with the help of Stat Soft software "Statistica 7.0". The advantage of the study lies in the fact that the Holstein of different origins were kept in the same environmental conditions. Intra-breed differences in lifelong productivity of imported cows were revealed. The lifetime milk yield of Danish animals exceeded the average by 1336 kg, fat by 73.4 and protein by 60.7 kg. However, the offspring of imported Hungarian cows were the most suitable for industrial technology. They surpassed the Danish and German opponents by 0.4 and 0.5 lactation in productive longevity, by 9213 and 9688 kg in lifetime milk yield, by 106 and 239 kg in fat and by 72 and 202 kg in milk protein. In general, in conditions of industrial milk production technology, the duration of first-generation cow productive life was reduced by 1.0 lactation (td = 5.6 or P≥ 0.999), in average it was 2.6 lactations. At the same time, the lifetime milk yield of imported animal offspring was significantly lower by 7167 kg, that is, by 20.9% -decreased from 34245 to 27078 kg (td = 2.6 or P≥0.99). As a consequence, the first generation cows' milk fat and protein were lower by 23.0 (td = 3.3 or P≥ 0.999) and 24.1% (td = 4.8 or P≥0.999). It was found that the variability of the signs (Cv) ranged from 14.7 ... 15.4 (protein content) to 42.0 ... 52.6% (milk yield), increasing in the first generation from 11.4 ... 16, 8 to 53.6 ... 56.1%, which indicates the possibility of carrying out effective breeding. Female offspring of imported cows have a low heritability in lifetime milk yield (h2 = 0.02 ... 0.18), in milk fat yield (h2 = 0...