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.

Finding livestock breeds that are resistant to high temperatures may be one of the strategies for mitigating the impact of global climate change on dairy farming. In this investigation, we studied the heat resistance of Holstein (HB) and Brown Swiss (BS) cows on two commercial dairy farms under the hot summer conditions of Ukraine. The physiological response of animals determined heat resistance by measuring rectal temperature (RT) and respiratory rate (RR) in the morning (from 4:00 to 6:00) in comfortable conditions and the afternoon (from 14:00 to 16:00), during heat load. The temperature-humidity index (THI) was used to characterize weather conditions and microclimate in naturally ventilated rooms (NVBs). BS cows were found to be heat resistant. The reaction of HB cows to the heat was manifested by higher growth of RT and RR, and they suffered significant losses in the daily milk yield per cow in the summer. Further research will need to elucidate the biological and genetic mechanisms of the identified breed differences in heat tolerance of dairy cows.

The achievements of modern domestic pharmacy clearly prove the prospects of searching for biologically active molecules among 1,2,4-triazole derivatives. The aim of our work was to predict the safest compound, select it and unambiguously prove the structure of a new promising molecule, to investigate some parameters of its toxicity. Materials and methods. X-ray diffraction analysis was performed in the laboratory of the Institute of Single Crystals of the National Academy of Sciences of Ukraine (Kharkiv). Computer methods were used to build “structure – toxicity” models and predict LD50 using already created models GUSAR, TEST. The degree of toxicity (DL50) and the approximate doses for the subacute experiment were determined by studying the acute toxicity of the test chemical and the injectable solution based on it. Determination of acute toxicity parameters by intragastric administration was performed on white rats, aged 3-4 months, body weight 200-220 g. Results. Due to the study of the toxicity of 1,2,4-triazole derivatives by non-experimental methods using GUSAR and TEST models, it was found that the test compounds could be classified as low-toxic substances. The compound is an organic salt that exists in the crystal as a solvate with one molecule of methanol and two molecules of water. When studying the structure of the crystal, it was found that the crystal is in the pinacoidal triclinic syngony. According to the results of the studies, it was found that after a single intragastric administration of the compound in doses of 1000, 3000 and 5000 mg / kg, all animals remained alive for 14 days. The basis of the biological action of chemical compounds is the violation of several biochemical processes. We found that the studied blood constants, on the background of the use of newly synthesized substance, underwent some changes. Conclusions. According to the assessment of the toxicity of the drug “VPK-434” when administered intragastrically to laboratory rats, it was found that in accordance with SOU 85.2-37-736: 2011 the test substance belongs to the IV class of toxicity (low toxicity). It was found that the average lethal dose of DL50 of the test substance by intramuscular administration to rats is 1666.66 mg / kg body weight. It was studied that some abnormalities in the hematopoietic system (increase in the number of leukocytes, including eosinophils), liver and kidney function (increased activity of transaminases, decreased serum concentrations of total protein, urea and creatinine) and changes in mineral metabolism of experimental animals groups, on the background of receiving 10 multiple doses of the study drug, was short-term, and the restoration of the functional state of the body of rats could be said as early as 4-5 days after discontinuation of the drug into their body

The aim of the study was to investigate the effect of the feed additive “Butaselmevit-plus” on the state of the antioxidant defense system of piglets during weaning. The experiments were conducted on the basis of the LTD “KOSHET” Mukachevo district of Zakarpattia region. Two groups of piglets were formed – control and experimental, in the amount of 10 individuals in each group, selected on the principle of analogs – age, breed and body weight. Animals were fed according to the norms for this age of pigs. On the 28th day of life, the piglets were weaned from the sow and regrouped from different nests for further maintenance during fattening and rearing with a change in the structure of the diet, which served as technological stress for the animal's body. Piglets of the experimental group, from 21 to 40 days of age, were additionally fed the feed additive “Butaselmevit-plus” at a dose of 100 mg/kg body weight per day. The material for the study was blood, which was taken in the morning before feeding the animals by puncture of the cranial vena cava for 20 days of life (the period before weaning), for 25 days of life (the period before weaning), for 30 days of life (2 days after weaning), for 35 days of life (7 days after weaning), 40 days of life (12 days after weaning). It is proved that feeding piglets feed additive “Butaselmevit-plus” enhanced the antioxidant status of piglets after weaning. It was found that under conditions of technological stress, the use of feed additive “Butaselmevit-plus” in the amount of 100 mg/kg body weight per day improves the antioxidant defense of the body, as evidenced by an increase in blood 35-day-old piglets superoxide dismutase activity by 26.7 % (P < 0.001), catalase – by 39.5 % (P < 0.001), glutathione peroxidase – by 51.7 % (P < 0.05), glutathione reductase – by 52.9 % (P < 0.05), the content of reduced glutathione – at 58.3 % (P < 0.001). These results confirm the effectiveness of the use of milk thistle, methionine, selenium, and vitamins A, E, and D3 in the feed additive “Butaselmevit-plus” to piglets in the period before and after weaning to activate the protective systems of their body.

The study aimed to investigate the effect of milk thistle, methiphene, and silimevit on the liver's protein-synthesizing function of laying hens in examination chronic cadmium toxicosis. Thirty-two chickens, 78 weeks old, were selected for the study. Four groups were formed: control and three experimental. Birds of the experimental group (E1) with fodder were fed the fruits of milk thistle at a dose of 2.0 g/kg of feed once a day for 30 days. Chickens of the experimental group (E2) were fed metifen at a dose of 0.28 g/kg of nutrition once a day for 30 days. Hens of the experimental group (E3) were fed silymevit at a dose of 0.36 g/kg of feed nutrition once a day for 30 days. The results showed that the total protein content and its plasma fractions of birds vary throughout the research in poultry control and experimental groups. Thus, in the blood of laying hens subjected to cadmium loading, a decrease in their blood of total protein and albumin fraction was found. Under the cadmium toxicosis of chickens, milk thistle, metifen, and silimevit positively affect the liver's protein-synthesizing function, as indicated by an increase in the total protein level and albumin. Feeding with milk thistle and silymevit contributed to a better normalizing effect on the liver's protein-synthesizing function than the use of metifen.