This experiment was conducted to study the effect of a prolonged hot period on the fatty acid (FA) composition in blood serum of dairy cows. Eighteen multiparous Holstein cows were randomly assigned to the hyperthermia group (HYP, n = 8) in August (summer season) and the control group (CON, n = 10) in October (autumn season). Blood from animals of the HYP group was collected in one heat wave, which was preceded by a long period of heat stress (HS, temperature-humidity index (THI ≥ 72)). Blood from cows of the CON group was collected under thermal comfort conditions (THI < 68). The spectrum of free fatty acids (FFA) in the blood serum was analyzed by gas chromatography. The concentration of FFA increased, including saturated FAs and monounsaturated FAs, in the blood serum of cows under conditions of prolonged HS. This was associated with the mobilization of FA into the bloodstream from adipose tissue, as a consequence of negative energy balance. An increase in the ratio of n-6/n-3 polyunsaturated FAs may indicate biomembrane dysfunction and adversely affect dairy cows. This study showed that prolonged periods of heat can affect the FA composition of blood. How much this leads to changes in the FA composition of milk and the quality of food products remains to be seen in further research.

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The problem of free radical pathologies in high temperatures in animal husbandry and veterinary medicine is extremely important scientific and practical. In the process of hyperthermia, the structure of cell membranes, the permeability of membranes, and membrane transport systems change, which cause the oxidation of unsaturated fatty acids and the accumulation of toxic products of a radical nature. This plays an important role in the development of many pathological conditions. The review article describes the problem of the influence of heat stress (HS) on a living organism and the problem of hyperthermia in animal husbandry. Emphasis is placed on the role of the body's antioxidant system in a state of HS and the use of antioxidant drugs as additives into feed for farm animals, aimed at mitigating the course and harmful effects in HS. On the one hand, our goal was to describe in an accessible form the main complex biochemical disorders in the body under HS conditions, which lead to a deterioration in the welfare and loss of productivity of animals. On the other hand, we tried to show the special role of the antioxidant defense system in preventing the development of oxidative stress in its classical representation. Also, we substantiated the choice in favor of using natural and synthetic antioxidants as one of the strategies for the prevention of HS in modern animal husbandry.

Seasonality affects milk production, its composition, as well as the spread of mastitis in dairy cows. The aim of the research work was to study the way the seasons affect milk productivity and the manifestation of mastitis among Ukrainian brown Swiss cows at a commercial dairy unit, with the animals kept in naturally ventilated premises. The relationship between the indicators was assessed by Spearman’s rank-order correlation coefficient. The influence of a seasonal factor and individual air parameters on cows’ milk productivity was evaluated using Factorial ANOVA in Statistica 12 software. The results of the study revealed a high correlation between the content of milk fat and milk protein and the weather conditions (temperature, relative humidity, as well as temperature-humidity index) by seasons. Moreover, the greatest negative relationship between these characteristics was observed in spring (r = 0.4‒0.8) and in autumn (r = 0.6), and not in summer during the heat, as we had predicted earlier. The influence rate of the «season» factor was significant both in terms of the daily milk yield and milk components (51–59%) and mastitis prevalence rate in cows (56%) at the dairy unit. In general, the reduction of milk yields in summer and especially in autumn, and the spread of udder pathology in cows during this period should provide for the introduction of managerial and preventive veterinary measures to mitigate the effects of hot summer among Ukrainian Brown Swiss cows at year-round housing of animals in naturally ventilated premises.

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.

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...

В статті розглядається ініціатива щодо побудови системи метрологічного забезпечення зразків озброєння та військової техніки іноземного виробництва, яка ґрунтується на методі експертних оцінок. Наводяться рекомендації щодо обмежень, вводяться допустимі припущення та розкриваються етапи проведення робіт для отримання обґрунтованої кількості мінімально необхідних параметрів та послідовності їх контролю при метрологічному обслуговуванні зразків озброєння та військової техніки іноземного виробництва, опираючись на їх використання під час ведення бойових дій. Надаються поради щодо обрання експертів та оцінки результатів їх діяльності.