The aim of the research was to evaluate the microbiocenosis of the intestines of calves with digestive disorders. For experimental work, 2 groups of young Ayrshire cattle aged from 5 to 10 days were formed. The first group included 6 healthy calves, and the second group included 6 patients with diarrhea. Faeces were obtained from animals from the rectum and examined using the molecular genetic method. Changes in the microbiome during diarrhea were accompanied by an increase in the total microbial mass in the intestinal contents (by 1× 108.2), which indicated the activation of bacterial reproduction and the inability of the body to suppress their growth. In the structure of the fecal microbiota of healthy calves, 78.3% of the total amount of microbial DNA was accounted for by the normoflora, and in patients this indicator was 49.1%. In the microbiota of calves with diarrhea, an increase in opportunistic and pathogenic species was observed to 50.9 abs.%. Of the undesirable microorganisms, the concentration of Enterobacteriaceae bacteria increased by 7.36 abs.%, Sneathia spp., Leptotrichia spp., Fusobacterium spp. by 21.47 abs.%, Staphylococcus spp. by 0.01 abs.%. There was also an increase in representatives of the normoflora: Lachnobacterium spp., Clostridium spp. and Lactobacillus spp. An increase in the concentration of lactic acid microorganisms in the fecal microbiota of sick calves is probably associated with impaired lactose absorption. A possible trigger of the disease in the calves under study is the dysfunction of the digestive system, and changes in the microbiota occur against the background of the formation of a favorable environment for certain groups of microorganisms. The data obtained will make it possible to develop effective methods for correcting the microbiome and reduce the risk of gastrointestinal pathologies in cattle.

Probiotics are microorganisms that have beneficial properties that can have beneficial effects on the host organism. Chickens, pigs, and cattle are the most common farm animals around the world. In this regard, maintaining the microbial balance of the gut is an important task for veterinary medicine. It was previously established that probiotic efficacy has been proven for representatives of the genera Lactobacillus and Bifidobacterium, and Akkermansia and Faecalibacterium are considered as probiotics of a new generation. The aim of the work is a comparative analysis of the gut microbiome of chickens, pigs and cattle for the presence and relative content of probiotic microorganisms in it. Initially, the prevalence of phylum Bacteroides, Firmicutes, and Actinobacteria in the faeces of all the farm animals studied was shown. The Firmicutes phylum turned out to be the most widespread phylum isolated from chicken fecal samples, while the Bacteroides phylum dominated the gut microbiome of cows and pigs. When analyzing the relative content of proteobacteria, it was found that the intestinal microbiome of cows is represented by bacteria of the classes Betaproteobacteria and Epsilonproteobacteria, and in pigs almost exclusively by the class Epsilonproteobacteria. In the samples obtained from pigs, piglets and chickens, the dominance of bacteria of the genus Lactobacillus over Bifidobacterium was established. The simultaneous presence of probiotic bacteria of a new generation, Faecalobacterium prausnitzii and Akkermansia muciniphila, was identified only in faecal samples obtained from cows, while the relative abundance of bacteria Akkermansia muciniphila was 50.0 times higher than the number of Faecalobacterium prausnitzii in the samples. The bacterium Faecalobacterium prausnitzii was identified in pig faeces, and Akkermansia muciniphila was identified in chicken faeces. It is noteworthy that the presence of new generation probiotics in the intestines was not detected in piglets aged 5-10 days.

Viral hemorrhagic septicemia is one of the most dangerous fish diseases, causing significant damage to the economic development of aquaculture. In the Russian Federation, diagnostic measures to identify this pathogen are usually based on serological approaches. However, the fastest and the most accurate methods are molecular genetic diagnostic methods based on the polymerase chain reaction. The aim of this work was to develop a combination of primers and probe suitable for specific PCR indication of hemorrhagic septicemia virus in real time. At the first stage of the work, a bioinformatic analysis of the currently available nucleotide sequences of the genomes of the viral hemorrhagic septicemia causative agent was carried out. After analyzing the sequences of this virus, a marker locus of 180 bp was determined inside of the N gene encoding the nucleoprotein. Inside of this locus, primers and a probe suitable for detecting isolates of viral hemorrhagic septicemia in the real time polymerase chain reaction were developed. As a result of a series of experiments conducted on cDNAs isolated from VHSV CF 1.2 and VHSV 22-ARM virus cultures, the 1.2 and VHSV 22-ARM virus cultures, the amplification program and the composition of the reaction mixture were determined. It has been established that the developed primers have 100% specificity, and sensitivity can reach 12 copies of virus particles per microliter. Thus, the nucleotide markers selected as part of that work and the primers and probe constructed on their basis have all the characteristics necessary for their use as the basis of a test system that allows for rapid PCR indication of the virus to detect and identify the causative agent of viral hemorrhagic septicemia.

Pathology caused by S. aureus in poultry remain a matter of much concern for poultry industry. In the present article we study certain aspects of infection, experimentally induced in chickens with Staphylococcus aureus, namely methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) and of its treatment. Chickens of Hisex Brown cross were challenged by intraperitoneal injection of Staphylococcus aureus in suspension at a dose 3.0 x 10^8 CFUs / 0.5 mL (2 McFarland/0.5 mL). The reliable data that we obtained show that the clinical signs of staphylococcosis develop in chickens 24 hours sooner on the average when the chickens have been challenged with MRSA than after the challenge with MSSA. In the former case the clinical signs are more severe and result in the death of model animals much more often. We studied the effectiveness of some antimicrobials such as lincomycin, enrofloxacin and levofloxacin, administered via drinking water at a concentration 300 mg/L, for treatment of chickens, challenged with S. aureus with different susceptibility to the aforementioned drugs. We proved that lincomycin, enrofloxacin and levofloxacin, administered via drinking water at a concentration 300 mg/L, for treatment of chickens, challenged with MRSA, have low effectiveness. Accordingly, the mortality rate for the chickens, treated with enrofloxacin was as high as 84%, lincomycin – 76% and levofloxacin – 56%. And on the contrary, the treatment of experimental staphylococcosis, caused by the isolate, susceptible to the above-mentioned drugs, led to much better results. Remarkably high effectiveness was achieved when we administered enrofloxacin (92%). The effectiveness was a little lower in the cases of lincomycin and levofloxacin (76%).

Within the framework of the Russian Science Foundation Grant No. 24-76-10044, a candidate vaccine strain of avian influenza virus A/Syktyvkar/PR8/6:2/HA20 (H5N1) was obtained, which has a low-virulent phenotype due to replacement of the hemagglutinin cleavage site. This virus does not cause the death of developing chicken embryos during incubation and the clinical manifestation of the disease in animals upon infection. The article presents the results of studies on the safety and harmlessness of a recombinant strain of avian influenza virus A/ Syktyvkar/PR8/6:2/HA20 (H5N1). No hemorrhages or lesions were observed in embryos infected with the live recombinant virus. The data obtained indicate the safety of the A/Syktyvkar/PR8/6:2/HA20 virus for embryonated chicken eggs. The study of harmlessness was carried out with intraperitoneal administration of an inactivated virus to white mice (this group also served as a control for inactivated drugs), and with the introduction of a virus inactivated with formalin, betapropiolactone and a mixture of theotropin and merthiolate. No significant weight loss was found in any of the observed groups, which indicates the harmlessness of the A/Syktyvkar/PR8/6:2/HA20strain for white outbred mice, as well as the good tolerability of drugs obtained using all the studied inactivation schemes. The harmlessness of an inactivated vaccine made from the inactivated virus strain with the addition of aluminum hydroxide as an adjuvant was tested by studying changes in the live weight of one-day-old Dekalb White cross chickens. In all study groups, there were no signs of exhaustion, intoxication, or signs of disease, which indicates complete inactivation and harmlessness of the virus. An assessment of the vaccine's harmlessness was also carried out on ten 150-day-old Dominant chickens. After a 10-fold inoculation dose was injected into the pectoral muscle, the birds were monitored for 28 days. All chickens remained alive during the specified time, with no visible clinical signs of illness, and there were no signs of an inflammatory reaction at the injection site. Thus, it can be concluded that the A/Syktyvkar/PR8/6:2/HA20 (H5N1) strain is safe, and inactivated vaccines made from this strain are completely harmless.

Spring carp viremia is a contagious disease affecting cyprinids, primarily the common carp (Cyprinus carpio). The disease is endemic in Europe, America and several Asian countries, where it causes significant morbidity and mortality in affected fish. The Office International des Epizooties (OIE) has included spring carp viremia (SCV) in the list of notifiable diseases. The virus is excreted mainly in the faeces and urine of clinically infected fish and by the carriers themselves. Diagnosis should be confirmed by virus neutralization or polymerase chain reaction (PCR) and nucleotide sequence analysis of the PCR products. There is no treatment for spring carp viremia. This article is devoted to the development of primers for real-time polymerase chain reaction to detect the genome of the spring carp viremia virus. The studies were conducted at the Kropotkin Regional Veterinary Laboratory in Kropotkin, Krasnodar krai. Carp samples were collected by taking tissue material and exudate from the abdominal cavity. Primers were selected at the Department of Biology, Ecology, Parasitology, Aquatic Bioresources and Aquaculture of the Ulyanovsk State Agrarian University. The study material included 4 organ samples from carp fish received by the Kropotkin Regional Veterinary Laboratory. Real-time polymerase chain reaction was performed in a reaction mixture volume of 25 μl per 1 RNA sample. The samples under study were detected using a CFX 96 Bio-Rad (USA) amplifier. Fluorescence was measured by channels at the 5` ends with FAM/green dye and at the 3` ends with BHQ1 quencher. As a result of the RTPCR, 6 fluorescence curves were identified, together with two positive controls, crossing the Threshold line. The values of the "Ct" indicator ranged from 13 to 35. The obtained results of the reaction indicate their good reproducibility and reliability.

The focus of clinical microbiology is on the problems of the emergence, spread and evolution of microbial resistance to antibiotics. Antibiotic resistance is evaluating as one of the significant threats to humanity and livestock in the 21st century. This is due to the fact of the slowdown of the development of new antimicrobial drugs, there for increasing the antibiotic resistance and the emergence the pan-resistant strains of microbes. Currently, the problem of antimicrobial resistance of bacteria has reached alarming proportions, which leads to a decrease in the effectiveness of therapy for bacterial infections and the necessity to use more expensive drugs. Antibiotic resistance of bacterial strains is one of the most serious threats to modern veterinary medicine and health care, which has arisen as a result of uncontrolled, and in some cases unreasonable use of antibiotics in agriculture and medicine. Common bacterial infections may become incurable in the future, resulting in mass diseases among the population and animals. The seriousness of the current situation has prompted the World Health Organization (WHO) to compile a list of antibiotic-resistant pathogens, the spread of which poses the greatest threat. The WHO initiative aimed to draw the attention of all interested organizations, including research organizations, pharmaceutical companies and government agencies, to solving the problem of the growing resistance of microbes to antibiotics. The solution to the problem can be found in the development of clear, scientifically based rules for the use of antibiotics and the search for alternative drugs. The article provides an overview of the main causes of the development of antibiotic resistance in microorganisms, as well as brief information on the most interesting approaches to the creation of new antibacterial agents and analyzes the most promising of them (vaccination, probiotics, phage therapy, immunostimulants, technological prevention, etc.).

The aim of this study was to select the optimal algorithm for working with the Ornithobacterium rhinotracheale OR-21 strain, which is promising for use as a production strain for the manufacture of a vaccine against ornithobacteriosis in birds, based on the study of its biological properties, virulence, and genetic characteristics after a series of its passages on nutrient media and SPF chicken embryos. When selecting nutrient media, growth additives, and cultivation conditions for the strain, the composition, sensitivity, inhibitory and differential properties of the media used, the growth rate, and the preservation of the stability of the biological properties of the cultured microorganism were taken into account. When selecting nutrient media, growth additives, and cultivation conditions for the strain, the composition, sensitivity, inhibitory and differential properties of the media used, the growth rate, and the preservation of the stability of the biological properties of the cultured microorganism were taken into account. In experiments on conducting passages of O. rhinotracheale OR-21 strain cultures, 5–7- day old chicken embryos were used as a laboratory model in vivo. The virulence properties were assessed on laboratory animals using generally accepted methods. In the experiments, Russian White chickens were used as a laboratory model. In the process of choosing a laboratory model for conducting passages, it was found that chicken embryos are highly sensitive to the studied strain and allow obtaining a higher concentration of Ornithobacterium rhinotracheale OR-21 microbial cells, compared to passages on nutrient media. In addition, the use of SPF chicken embryos, unlike poultry, made it possible to exclude contamination with foreign microflora during passages. 2207 genes were identified for O. rhinotracheale. No differences were found when comparing the genomes of cultures of passages 1 and 10. The highest homology of the isolate after 10 passages is observed with the typical strain O. rhinotracheale DSM 15997. It was found that, on nutrient media, the maximum number of passages of the strain culture is limited to 6 transfers, while on chicken embryos, the causative agent of ornithobacteriosis continues to multiply, but loses virulence in relation to them and 240-day-old chickens. The loss of virulence does not affect other biological properties of the strain.

Due to the development of resistance in ectoparasites, it is advisable to use complex insectoacaricides for the treatment and prevention of arachnoentomoses in domestic animals, which not only reliably protect, but also do not cause intoxication. The aim of the research was to study the therapeutic efficacy and the effect on the functional state of dogs and cats of insecticidal drops Neoterika Protecto 4 in case of ctenocephalidosis. The spread of the invasion and experiments to determine the effectiveness and safety of the insecticide were carried out on cats and dogs of different social status. It was found that the use of insectoacaricide drops Neoterika Protecto 4 allows you to rid cats and dogs of fleas 48-72 hours after a single point application of the drug to the skin in the area between the shoulder blades. It is noted that the less the abundance of parasites on the animal, the faster the recovery. The residual insecticidal effect of the drug was at least thirty days. No deviations in the physiological state and behavior of animals were found. It was determined that flea infestation did not cause significant changes in the homeostasis of animals in terms of creatinine, urea, ALT and AST. In dogs of all ages studied, the de Ritis coefficient before the experiment was in the lower limits of the reference range, and three days after the use of the studied insecticide, the aminotransferase ratio approached the reference values. In cats, an increase in the de Ritis coefficient was recorded before the start of treatment, and high values were maintained immediately after the use of the studied insectoacaricide. In cats aged 1-7 years, a decrease in the aminotransferase ratio was observed, and in older cats, on the contrary, an increase in the de Ritis coefficient occurred. When using insectoacaricides, it is necessary to take into account the initial functional state of animals and, if necessary, include hepatoprotectors in the protocol of therapeutic measures to prevent the development of side effects and damage to the detoxification organs, especially in cats over seven years old.

In the conditions of industrial poultry farming, the body of poultry is negatively affected by numerous stress factors, which leads to the development of immunodeficiency conditions, increases susceptibility to infectious diseases, reduces the safety and productivity of livestock. In this regard, the use of immunocorrecting drugs is very relevant for poultry farming. The aim of the study was to study the effectiveness of using a phytobiotic based on a complex of essential oils of cinnamon, cloves, rosemary, thyme and sesame seeds to enhance cellular and humoral immunity of poultry. The studies were carried out on broiler chickens of the «Smena 9» cross, of which control and experimental groups of 70 heads each were completed at the age of one day. The chickens of the experimental group received phytopreparation in a dose of 0,2 ml/l of water from the 1st to the 7th day of cultivation and 0,3 ml/l of water from the 8th to the 38th day. At the age of 9 days, poultry was vaccinated against the Newcastle disease virus. Based on the research results, it has been established that the use of a preparation based on essential oils increases the adaptive abilities of broiler chickens after vaccination, reduces the negative effects of stress factors (biological, technological) on the body, activates cellular and humoral immunity. The phytobiotic had a greater effect on cellular immunity, as evidenced by an increase in the content of lymphocytes by 1,8 times, Tlymphocytes – by 2,9 times, B-lymphocytes by – 1,7 times, cationic proteins – by 40,3- 85,6%, and the level of spontaneous and stimulated HCT activity of neutrophils by 37,3-49,0%. The use of the drug contributed to an increase in the average titer of postvaccination antibodies to the Newcastle disease virus by 0,5-0,8 log₂.

The effect of ciprofloxacin on the membrane reserve and resistance of ducklings' erythrocytes to hypotonic environment in experimental staphylococcosis was studied. The high permeability of the erythrocyte membrane to ciprofloxacin can lead to a change in the resistance of red blood cells to conditions of reduced osmolarity. The study involved three groups consisting of Bashkir ducklings aged 21 days. Group III birds were treated with ciprofloxacin at a dosage of 200 mg/l for five days. A day after the start of antibiotic treatment, intraperitoneal infection of groups II and III with Staphylococcus aureus culture at a concentration of 5McF was performed. Intracardiac puncture blood sampling was performed on the 1st, 3rd, 6th, 9th, and 13th days after infection. To assess the resistance of red blood cells to hypoosmotic pressure, blood was incubated in an isotonic solution (0.93% NaCl), in a hypotonic solution (0.33% NaCl), in a ratio of 1:1 during 30 seconds. Linear parameters of erythrocytes were determined in blood smears, surface area and volume, and indicators of membrane reserve were calculated. The relative membrane reserve of erythrocytes in birds of the control group in conditions of hypoosmolarity was the highest compared with the experimental groups. This is due to the initial increase in the size of bird cells of groups II and III under the influence of alpha-toxin St. aureus. The erythrocytes of intact ducklings demonstrate the maximum intensity of use of the relative membrane reserve in a hypotonic environment – iuMR% is in the range between 19.4% and 33%. In the second and third groups, the average value of iuMR% of the membrane is 17%. The involvement of surface plasmalemma reserves in the regulation of red blood cell size, as well as changes associated with ion and water transport, prevent hemolysis. The use of an intracellular membrane pools makes it possible to regulate the volume of nuclei under the aggressive action of alphahemolysin and ciprofloxacin.

The effect of sulfaguanidine, furazidine, nifurantel and sulfasalazine on the leukogram of chicken blood was studied. Five groups were formed for the study, consisting of day-old Hyssex Brown chickens. The control group received regular drinking water for 10 days, while chickens of groups II, III, IV and V received water with sulfaguanidine, furazidine, nifurantel and sulfasalazine at a dosage of 200 mg/l, respectively. Blood sampling by intracardiac puncture was performed on the first, third, fifth, seventh and ninth days after drug withdrawal. Eosinophils, basophils, pseudoeosinophils, lymphocytes, and monocytes were counted in Romanovsky-Giems stained blood smears. The leukocyte formula was found relative to the total number of leukocytes by the percentage of individual cell forms. The dynamics of the leukocyte intoxication index, the leukocyte displacement index, the lymphocytegranulocyte index, the Krebs index, the leukocyte index and the immunoreactivity index were studied by calculation. The statistical significance of the differences was assessed using the nonparametric MannWhitney U-test. Feeding chickens with nitrofurans (furazidine and nifurantel) and sulifanilamides (sulfaguanidine and sulfasalazine) leads to a change in leukogram values compared with similar indicators in the blood of chickens of the intact control group. The leukocyte indices of the blood of chickens treated with antimicrobial drugs from the groups of nitrofurans and sulfonamides remain without statistically significant changes. Furazidine causes a marked increase in the number of pseudoeosinophils during the first seven days after discontinuation of the drug, then this indicator returns to the control values. Nifurantel has virtually no effect on the physiological status of chicken blood, causing statistically insignificant deviations in the number of eosinophils and lymphocytes. Sulfaguanidine and sulfasalazine do not cause significant changes in the leukocyte formula of chicken blood.

The article describes the results of a study aimed at studying the mitotic activity of jejunum cells in healthy piglets and piglets with perinatal hypotrophy, as well as evaluating the effect of the drug “Prostimul” on the regenerative processes in the intestine in this pathology. Newborn piglets were selected for the study and the following groups were formed: healthy piglets (the first group) and piglets with perinatal hypotrophy, which were further divided into two groups: The second group - piglets with perinatal hypotrophy (n=20), which per os in addition to the main diet were given cow's milk in a dosage of 2.5 ml per head for 3 days (scheme used in the farm) and the third group - piglets with perinatal hypotrophy (n=20), which were intramuscularly injected with the drug “Prostimul” twice, on the first and third days of life at a dosage of 0.1 ml/ kg body weight. Immunohistochemical study with Ki-67 marker was carried out in the jejunum tissue of piglets before milk intake, as well as on 7, 14, 21 days. It was found that perinatal hypotrophy is characterized by a decrease in the intensity of cell proliferation processes. The dynamics of changes in Ki-67 expression indices indicates a gradual increase in the proliferative activity of cells in the jejunum with age in all experimental groups, which corresponds to the normal postnatal development of the organ, but the rate of these changes was most pronounced in the group of hypotrophic piglets receiving the drug “Prostimul”, which reduced the lag behind the healthy animals.

Evaluation of rat behavior in experimental studies is important for understanding neurophysiological and psychopharmacological processes. The aim of this study is to investigate the effect of paracetamol on the behavioral responses of laboratory rats under chronic stress. Four groups of white outbred rats (N=48) were formed within the framework of the study. For statistical analysis of the data, specialized IBM SPSS Statistics version 21 software was used. The normality of distribution was checked using the Kolmogorov-Smirnov criterion. The data were then evaluated using one-way analysis of variance (ANOVA), with Tukey and Tamhane criteria used for multiple comparisons. The focus is on assessing changes in the cognitive and emotional spheres of animal behavior, as well as analyzing the possible neuroprotective properties of paracetamol under long-term stress exposure. This article describes changes in the behavioral responses of animals from different groups to objectively assess the effect of the drug on the levels of anxiety, depression, aggression and cognitive functions in rats under chronic stress. The behavior of rats on a board with holes, in a cage for measuring activity, in the Open Field and Elevated Plus Maze tests during a four-week study against the background of taking an aqueous solution of paracetamol is described. The results of this study confirm the hypothesis that the combination of stress and paracetamol intake has a significant effect on the behavioral activity of laboratory rats. This is manifested in a decrease in vertical and horizontal activity, changes in behavior in the elevated plus maze and a decrease in mobility in the open field. The obtained data can serve as a basis for further studies of the mechanisms of interaction between stress and pharmacological drugs on the central nervous system of animals.

The development of the pharmaceutical industry is directly related to changing working conditions in industrial complexes. Intensification of production increases not only animal productivity, but also labor productivity. Therefore, the use of drugs in animal husbandry should be convenient, simple and prolonged. For this purpose, a formulation of an application dosage form based on biopolymers has been developed, with the addition of herbal extracts, which has a viscousplastic, homogeneous consistency, with uniform distribution and adsorption on the skin, without adhesion to the skin and the ability to release the active substance by the polymer composition over a specified time. Application dosage forms are able to maintain a constant concentration of the active substance (AS) at the site of application for a long time, creating high concentrations of AS in cells. To develop this dosage form, experiments were conducted with various polymers (gelatin, starch, agar-agar) and dry extracts of medicinal plants. As a result, it was established that the most optimal components of the application dosage form are a combination of gelatin, starch, dry extracts of marshmallow root, oak bark. Bioavailability of the application dosage form was assessed by the kinetics of diffusion of active components into agar, by recording the cross -sectional distribution at temperatures of 25̊C and 37̊C. The degree of release of the active components of the application dosage form was judged by the diameter of the colored zones, which were measured after 1, 2, 3 and 4 hours. As a result of studies of the possibility of releasing the active substance from the polymer composition, smooth diffusion of the active substance from the application dosage form by cross-sectional distribution and the level of penetration into agar over time was established. Medicinal herbs in this composition act as biologically active substances, and are also formative components.

In modern animal husbandry, a large proportion of diseases of non-infectious etiology is occupied by animal injury, which leads to damage to the skin. We have developed a new antiseptic wound healing drug, which includes octenidine dihydrochloride, pantothenic acid and auxiliary components that potentiate the action of the main components of the drug. The study of sensitizing activity included two studies - the method of skin applications and a conjunctival test. It was conducted in accordance with the "Guidelines for conducting preclinical studies of medicines" edited by A.N. Mironov (2012), GOST 32375-2013 "Testing methods for the effects of chemical products on the human body. Skin sensitization assessment tests". The skin sensitization test included the determination of induction and provocative exposure, and was conducted on guinea pigs. Two groups of animals were formed – the study group and the control group. There were 20 animals in the study group and 10 in the control group. The second part of the study of the sensitizing activity of the drug is a conjunctival test. Guinea pigs were used for the study. Two groups of animals were formed – the study group and the control group, each with 10 animals. When assessing skin sensitization, the following results were obtained: redness, local increase in skin temperature, itching, thickening of the skin fold, peeling of the skin – were absent. There were no systemic changes, and the behavior of the animals did not change throughout the study. When examining a conjunctival sample, a gel with octenidine dihydrochloride caused redness in the area of the tear duct, cornea and sclera 15 minutes after administration of the drug under the upper eyelid. After 24 and 48 hours, there was no redness. There was no itching during each observation stage. There were no changes in the control group. No systemic changes were detected in both groups during the entire study period.

Meat is a key source of complete protein, whose nutritional and biological value is determined by the content of essential and non-essential amino acids. This is influenced by numerous factors, including storage conditions. One of the methods of increasing shelf life is low—temperature canning - cooling and freezing at certain temperature and humidity parameters, which helps preserve the structure of tissues and partially slow down autolysis, but leads to a transformation of safety indicators, nutritional value and amino acid profile. The aim of the study was to analyze the dynamics of the amino acid composition of pork of different quality categories depending on the temperature and humidity conditions of storage. The research was conducted in stages on the basis of the Educational and Research Center for Food and Animal Feed Expertise of the St. Petersburg State University of Veterinary Medicine. 102 pork samples were used as objects (17 samples each with defects of PSE, DFD, RSE, RFN, PFN and without defects). The analysis of the dynamics of the content of essential and non-essential amino acids in pork with various defects during storage revealed the dependence of their quantity on the type of defect and the duration of storage. The most significant fluctuations in the content of essential amino acids were established on the 5th, 6th, 8th, 10th and 12th days of storage, and for non-essential amino acids - on the 3rd, 7th and 11th. The results obtained, reflecting the patterns of changes in the amino acid profile of pork with qualitative defects at a temperature of -1°C and a relative humidity of 85%, are of key importance for optimizing technological processes.

Due to the widespread warming of the climate and an increase in the duration of the hot, dry period, heat stress is becoming an urgent problem of dairy cattle breeding. Highly productive animals are most sensitive to temperature stress, during which their daily milk yields can decrease significantly. The aim of the research was to study the dynamics of milk yields of dairy cows during the first four months of lactation in the summer. The studies were carried out in two farms located in the zone of insufficient moisture in the Stavropol Territory. The first farm is engaged in breeding Holstein cattle, the second is a black-and-white breed. In each farm, 3 experimental groups of animals were formed, 10 heads each, with an average daily milk yield in the first month of lactation: I experimental group – up to 20 kg; I experimental group – 20-30 kg; I experimental group – more than 30 kg of milk. The value of temperature stress was determined based on daily temperature and humidity data. In May, the absolute majority of days corresponded to the optimal values of temperature and humidity for keeping dairy cattle in both farms. In June and August, days with minimal and moderate heat stress prevailed. The milk yield of animals in the first experimental group increased significantly over the months of lactation. The milk yield of the first and fourth months of lactation of animals of the III and III experimental groups did not significantly differ. Thus, in medium-and highly productive animals of Holstein and black-and-white breeds, with minimal and average values of thermal stress, there is no significant change in milk yield over the months of lactation.

Poultry farming face’s objective challenges every day to ensure high viability of poultry in the context of industry intensification. In this work, an assessment was made of the influence of the domestic immunomodulatory drug "Azoxivet" on the postvaccination level of antibodies of broiler chickens of the "Ross-308" cross to the pathogens of Newcastle disease, infectious bronchitis of chickens and infectious bursal disease, as well as congenital non-specific factors of immune protection. The experiment was conducted in the vivarium of the Moscow State Academy of Veterinary Medicine and Biotechnology – the K.I. Skryabin Veterinary Academy. Broiler chickens were raised on the floor for 35 days. The dynamics of the increase in specific titers to Newcastle disease was higher in the experimental group – by 55.78% at the age of 28 days, by 28.44% at 33 days and by 10.49% at the end of the experiment. By day 35 of the experiment, the titer to infectious bronchitis of chickens also increased by 15.88%, but decreased by 11.62% to infectious bursal disease. According to the results of the experiment, a change in the indicators of nonspecific protection was noted. When testing for ELISA, the average titer against infectious bronchitis of chickens by the end of the experiment was higher in the experimental group than in the control - by 15.88%. However, against infectious bursal disease, the group receiving "Azoxivet" had lower antibody titers - by 11.62%. We noted that, with a decrease in BASK - by 3.69% and LASK - by 13.35%, FA increased - by 14.25%, FI - by 1.05% and FC - by 0.91%, compared to the control group. Based on the conducted research, we recommend the use of "Azoxivet" at a dose of 0.3 mg/kg of live weight of the bird.

Modern poultry farming technologies are often associated with stress factors that disrupt the balance between free radical production and antioxidant defense, potentially leading to oxidative stress. Consequently, maintaining optimal immune system function and enhancing antioxidant defense, particularly through exogenous antioxidants, is critical for poultry health and adaptation. This study aimed to evaluate the impact of the DHQEС complex (dihydroquercetin, vitamins E and C) on the expression of antioxidant and immune-related genes in the liver and intestinal tissues of broiler chickens under simulated stress. The experiment was carried out on broiler chickens of the «Smena-9» cross (n=40, N=160). A control group and three experimental groups were formed, which were subjected to stress (increase in stocking density by 10%). In addition to the basal diet, the third (from the 21st day of the experiment) and fourth (from the 1st day of the experiment) groups were supplemented with DHQEC: dihydroquercetin (32 mg/kg feed), vitamin E (10 mg/kg feed), and vitamin C (35 mg/kg feed). Realtime PCR was used to analyze the expression of Nrf2, GSH-Gpx, CAT, SOD, HO-1, AvBD9, IL-6, and IL-8 genes in liver and cecum. Results demonstrated that simulated stress reduced the expression of Nrf2 and GSH-Gpx in intestinal and liver tissues, along with decreased AvBD9 expression, indicating suppressed defense mechanisms. Prophylactic DHQEС administration mitigated these effects by upregulating Nrf2, GSH-Gpx, and HO-1 expression, while stimulating AvBD9 and IL-6. A positive correlation was observed between intestinal AvBD9 expression and average daily weight gain. These findings highlight the potential of the DHQEС complex to enhance stress resilience and productivity in broilers.

The efficiency of livestock farming, especially dairy farming, in the context of global warming is determined by a complex of factors: climatic conditions (heat stress), feed base, physiological state of animals and their genetic adaptability. Elevated temperatures provoke complex disorders in cattle, including metabolic disorders and decreased productivity. Against the background of climate change, the impact of heat stress on cattle is a serious problem for animal husbandry. The objective of the review: to consider the signs of adaptive qualities and thermotolerance of cattle. In the context of climate change, heat stress in cattle is becoming a major concern for the livestock industry. Studies of domestic and foreign authors show that when the temperature-humidity index (THI) exceeds the threshold value (> 66), animals experience physiological disorders (increase in rectal temperature, increased respiration, etc.), behavioral changes (decreased activity, reduced feed intake, etc.), biochemical shifts (increased cortisol, increased ketone bodies, etc.), and biochemical changes (increased cortisol, increased ketone bodies, etc.). ), biochemical shifts (increase in cortisol, increase in ketone bodies, etc.), decrease in productivity (decrease in milk yield, decrease in fat and protein mass fraction, change in fatty acid composition, decrease in live weight gain), deterioration of reproductive functions (decrease in fertilizability, and deterioration in sperm motility). Genetic studies have identified key markers of thermotolerance, including genes for heat shock proteins and factors (HSP and HSF), antioxidant enzymes, immunity and metabolism genes. However, selection is complicated by antagonism between productivity and stress tolerance. To minimize the consequences of negative effects of heat stress, it is recommended to control microclimate (ventilation, cooling) in livestock buildings, optimize feeding (introduction of antioxidant and vitamin supplements) and apply, along with traditional breeding methods, genetic selection using GWAS-analysis.

Oncological diseases are a serious problem in veterinary medicine, requiring special attention in diagnosis and treatment. In animals, malignant neoplasms are characterized by uncontrolled cell growth with invasive spread into surrounding tissues, which significantly complicates therapy and worsens the prognosis. The late diagnosis of tumors in animals is particularly difficult due to the absence of specific symptoms in the early stages. This necessitates an in-depth study of the mechanisms of neoplasm development in various animal species and the development of effective protocols for their treatment. In this work, we studied one of the most common malignant neoplasms in rats - mammary adenocarcinoma, which is a rather aggressive tumor developing from the glandular epithelium. The neoplasm under study is characterized by rapid invasive growth and a high tendency to recurrence. We conducted clinical examinations and treatment of female ornamental rats aged 1 to 2 years with a neoplasm in the breast area in the conditions of the Saratov Rodentovet veterinary clinic and the Vavilovsky University. For diagnosis, we conducted comprehensive clinical examinations, including a visual assessment of the animal's condition, a palpatory examination of the neoplasm and an assessment of the general status. The examination revealed dense, immobile formations with a diameter of about 1-1.3 cm, soldered to the underlying tissues, with unchanged skin above the tumor. We performed surgical procedures that allowed us to remove the tumors.

Damage or pathology of the venous bed in the area of the finger joints can lead to the development of edema, trophic disorders, secondary inflammatory processes and, as a result, lameness, which significantly reduces the mobility of animals and their productivity in industrial pig farming. A fundamental understanding of the relationship between the vascular system and the musculoskeletal system makes it possible to predict the consequences of injuries, infections, or circulatory disorders: for example, compression of veins in case of mechanical damage or deformity of the hoof horn can provoke tissue ischemia, tendon necrosis, or bone destruction, which requires urgent surgical interventions. The aim of the study was to establish the anatomical and topographic features of the veins of the finger joints in a Yorkshire pig and to determine the morphometric parameters. Cadaveric material for the study was delivered to the Department of Animal Anatomy of the St. Petersburg State Pedagogical University from the pig breeding complex of the Leningrad region. The study was conducted according to the periodization of pig life: the third stage of development is the second milk stage (22-45 days of the postnatal period). The study used newborn piglets for 28-30 days of the postnatal period of ontogenesis. 10 pelvic limbs obtained from five Yorkshire pigs were examined. During the study, anatomical and topographic features of the veins of the finger joints in a Yorkshire pig were established and morphometric parameters were determined. Knowledge of the anatomical and topographic features of the veins of the joints of the fingers of the pelvic limb in pigs is necessary to understand their physiological role in maintaining hemodynamics, tissue trophism and adaptation to stress. The venous system of this area provides not only blood outflow, counteraction to venous stagnation during prolonged static load, as well as drainage of metabolites from actively working muscles and joint structures. In addition, the variability of the anatomy of venous collaterals and their connection with deep and superficial circulatory systems necessitate an individual approach to surgery, therapy, and prevention of complications.

Mycotoxins are a group of biologically active substances, the penetration of which into the organism of farm animals cannot be completely prevented. The article presents the results of experimental studies on the adaptation of the PRODOSCREEN IFAAflatoxin B₁ kit for determining the concentration of aflatoxin B₁ in pig liver homogenates. The material (whole liver) was collected from one animal at a slaughterhouse. During sample preparation, the liver was homogenized and randomly divided into 5- gram portions. The technique is based on the formulation of a direct competitive enzyme immunoassay, the principle of which is the selective binding of a specific antigen to an antibody, which, under the action of an enzyme, as part of an antibody-bound conjugate, turns into a colored product. The essence of the set of measures for the adaptation of this method is to use the technique for searching for antigens not in the plant materials declared in the instructions, but in the organs of pigs. The article provides detailed data on the preparation of organ samples for the study, calculations of aflatoxin B₁ dosages introduced into the liver homogenate, and describes the stages of setting up an enzyme immunoassay. The data obtained during the experiment on the adaptation of the ELISA kit for determining the concentration of aflatoxin B₁ not only in plant materials, but also in pig liver homogenates, allow us to draw a number of conclusions where direct competitive ELISA can be used as part of a comprehensive diagnosis of mycotoxicoses in agricultural enterprises as an express method for qualitative (aflatoxin B₁ is in the organ / aflatoxin B₁ is not in the organ) assessment of the presence of aflatoxin B₁ in pig organs. Also, taking into account the measurement error from 0 to 28%, this method allows for a semi-quantitative assessment of the content of aflatoxin B1 in pig liver homogenate. We also noted that the lower the volume of Aflatoxin B₁ introduced into the liver homogenate, the lower the error in determining these concentrations using the direct competitive ELISA method.

The article presents the results of systematization of the coronary artery of the heart in 12 species of mammals (domestic, agricultural, commercial and fur-bearing animals). The aim of the work is to systematize data on the mammalian coronary bed, create anatomical nomenclature for their branches, and standardize the types of blood supply to the heart in the studied animal species. To conduct the study, we studied the branching of the coronary heart of agricultural (domestic bull, domestic goat, domestic sheep, domestic pig, domestic horse), commercial animals (brown bear, wild pig), furbearing animals (common fox, black Pushkin sable, Eurasian lynx) and domestic carnivores (domestic cat, domestic dog). The material was taken from private veterinary clinics in St. Petersburg and the Leningrad region, fur and fur farms, hunting grounds and private homesteads in the Leningrad region. The methods for the study were vasorentgenography, fine anatomical dissection, and the manufacture of corrosive preparations. Based on the analysis of anatomical preparations and vasorentgenography, the shortcomings of the existing International Anatomical Nomenclature have been identified, which does not take into account the functional significance and variability of heart vessels. A new classification is proposed, including the clarification of terms, the introduction of names for previously undescribed vessels, and the standardization of blood supply types, taking into account specific features. It was found that in wild boar, horse, and domestic pig, the right-handed and uniform types of vascularization predominate, while in ruminants, cats, dogs, and fur-bearing animals, the left-handed type dominates. The results make it possible to unify terminology, simplify the diagnosis of cardiovascular pathologies, and integrate the data into the curricula of veterinary universities.

Poultry farming in Russia is developing rapidly. The ability to obtain high-quality products for a minimum period of fattening of farm birds guarantees the country's food security and puts this industry in priority compared to other subsectors of animal husbandry. Currently, various feed additives are used in the feeding of farm birds, which contribute to a maximum increase in productivity while reducing the technological period of cultivation. The aim of the study was to determine the immunological status of broiler chickens against the background of the use of polysaccharide fraction of brown algae in compound feeds. The study was carried out on broiler chickens of the Smena 9 cross in the conditions of the Zagorskoye EPC in accordance with the VNITIP methodology. In each group there were 30 heads of chickens, kept without sex separation up to the age of 35 days in compliance with all technological parameters. In each group there were 30 heads of chickens, kept without sex separation up to the age of 35 days in compliance with all technological parameters. Phagocytosis parameters, lysozyme activity, serum bactericidal activity, and the concentration of immunoglobulins of classes A, M, and G were determined in the blood according to generally accepted methods. The polysaccharide fraction of brown algae contains mainly fucoidan. Fucoidan is a sulfated polysaccharide found in the cell walls of brown algae. Fucoidan has strong and important biological properties, including antiviral, antitumor, antioxidant, anticoagulant, immunomodulatory, antithrombotic, anticomplementary, and antiproliferative properties with potential benefits as immunostimulants and growth promoters in birds. In the course of the study, it was found that the use of polysaccharide fraction in the diets of broiler chickens is characterized by a stimulating effect on the factors of innate immunity, which is manifested in the activation of phagocytosis processes, an increase in bactericidal and lysozyme activity of the blood serum of broiler chickens. It should be noted that changes in the immunological status of chickens positively correlate with an improvement in zootechnical indicators.

Fur farming is a unique, young and developing branch of animal husbandry in the Russian Federation, which provides fur products not only to the country's market, but also exports 5-10% to non–CIS countries. Among fur farming, the most relevant is the breeding of sables, since the combination of their biological development features ensures high productivity of fur raw materials. Pathologies found in the structure of the limbs (joint deformities, muscle weakness, incorrect finger placement) lead to decreased activity, stress, injury, and even death of puppies in the first weeks of life. Therefore, modern farms strictly control the anatomical features of animals at the breeding stage: individuals with defects are excluded from breeding, giving preference to those whose morphological characteristics meet health standards. The aim of the study was to establish and study the course and branching of the arterial bed of the forearm area in Black Pushkin sables in the age aspect and to determine the morphometric parameters of the main vessels. The object of the study was male sables aged 15-20 and 36-40 months from birth. The number of animals studied was five in each group. The study was carried out using such methods as fine anatomical dissection, morphometry, photographing, vasorentgenography, computed tomography. During the study, the main arterial highways were identified, as well as their course and branching on the thoracic limb in the forearm area in black Pushkin sables in the age aspect. The main dynamics of vascular diameter increase is observed by an average of 1.52 times in individuals at 36-40 months of life, compared with sables 15-20 months from birth. This fact is due to the fact that, despite the cellular content of animals, sables are active animals, and the pectoral limbs perform a number of vital functions, in which their need increases with age.

The improvement of classical and the development of new methods for diagnosing the condition of the skeletal skeleton of the musculoskeletal system remains one of the urgent problems in the field of clinical anatomy, which is of applied importance for veterinary medicine and veterinary and sanitary expertise. At the same time, when assessing the state of the musculoskeletal system, the parameters of the anatomical norm and its variants are not always taken into account, which simulates numerous diagnostic errors. One of the objective and accessible methods of radiological diagnosis of the state of the osteoarticular system is an overview radiography, which provides objective information about the morphological features of the mineral phase of the bone substance. The article presents X-ray anatomical parameters of the bone skeleton of the thoracic and pelvic limbs of animals of various taxonomic groups. The research was performed at the A. F. Klimov Department of Animal Anatomy and Histology of the Moscow State Academy of Veterinary Medicine and Biotechnology – MBA named after K. I. Scriabin. The methodological approach used included conventional and fine anatomical dissection, X-ray imaging, radiometry with subsequent determination of bone development indices, comparative X-ray anatomical analysis and statistical processing of the obtained digital data. The aim of the study was to develop an algorithm for X–ray anatomical assessment of the state of the osteoarticular system in animals of various taxonomic groups. X-ray anatomical parameters of the condition of the bone skeleton of the extremities have been established. Along with the general patterns of the anatomical structure, species-specific features have been identified, which are not only an indicator of the norm of the structure, but also its variant, which is extremely important to take into account when deciphering radiographic information. The data obtained can be basic in comparative and clinical anatomy of animals, in identifying pathologies of their musculoskeletal system, as well as in matters of forensic veterinary examination.

Macrovesicular steatosis is a common liver pathology of common carp (Cyprinus carpio). Detection and quantitative assessment of specific markers of macrovesicular transformation of liver tissue of common carp will allow to optimize methods of prevention and therapeutic correction of this pathology in conditions of intensive aquaculture, which is of significant economic importance for the fish farming industry. The aim of the work was to conduct a quantitative analysis of lipid infiltration patterns in macrovesicular steatosis in common carp (Cyprinus Carpio). The study used 20 common carp individuals weighing 800-900 g, grown at the JSC "Fish Nursery" in the Voronezh Region. To simulate the acute phase of inflammation, the aquatic organisms were divided into 2 groups: the control group (n=10) and the experimental group (n=10) contained in an aquatic environment with the addition of copper sulfate II (CuSO4*5H2O) at a concentration of 60 mg/l in terms of the metal ion. Biological material from the studied individuals from each group (n=10) will be collected 56 hours after the start of the experiment. To confirm fatty degeneration, sections were made from the selected liver samples on a freezing microtome, which were stained with a composite dye of Sudan III and scarlet red to identify neutral fats in hepatocytes. All stained preparations were enclosed in a water-soluble glycerin-gelatin medium and also viewed under a light microscope. Quantitative analysis shows the predominance of fatty inclusions over the functional parenchyma of the liver, which disrupts the functioning of the organ. A combined approach combining classical histological methods with modern quantitative analysis may be effective for diagnosing fish liver pathologies and is recommended for implementation in veterinary laboratories.

Aluminum is one of the most abundant elements in the Earth’s crust and is widely used in industry, domestic applications, and medicine. Despite its extensive utilization, its potential toxicity remains a subject of active scientific debate and investigation. The main routes of aluminum entry into the human body include food, drinking water, inhaled air, and pharmaceutical products, all of which contribute to its accumulation in biological tissues and increase the risk of chronic intoxication. Vulnerable populations include children and individuals with impaired renal function, particularly those with chronic kidney disease. The aim of this study was to evaluate the effects of chronic exposure to aluminum hydroxide on kidney morphology and the expression of Mt1a, Mt2a, and Mt3a genes in rats, with an emphasis on identifying dose-dependent effects and elucidating possible mechanisms of nephrotoxicity. The experiment was conducted on 40 female white rats randomly assigned to one control and four experimental groups (8 animals each). Over the course of four months, the experimental groups received aluminum hydroxide orally in varying doses. Toxicity assessment included quantitative real-time PCR analysis of gene expression and histological examination of renal tissue. Significant upregulation of Mt2a and Mt3a was observed at higher aluminum doses (p < 0.001), while Mt1a expression demonstrated high interindividual variability. Histopathological evaluation revealed signs of interstitial inflammation, fibrosis, and chronic glomerulonephritis. Chronic exposure to aluminum hydroxide induces pronounced dosedependent morphological and molecular changes in the kidney. The Mt2a and Mt3a genes may serve as promising molecular biomarkers of aluminum-associated nephrotoxicity.

The study is devoted to the assessment of trypsin activity in the duodenal contents and blood of Hisex White laying hens using biochemical and molecular genetic methods. The aim of the work is to study the enzymatic activity of trypsin and the expression of its genes (PRSS2, PRSS3) depending on the composition of the diet. The experiments were carried out on hens with chronic duodenal fistula, whose diet complied with the standards of VNITIP (17.7% crude protein, 282 kcal/100 g). All studies on poultry were carried out in accordance with the requirements of humane treatment of animals (European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (ETS No. 123) [Russian, English] (Strasbourg 18.03.1986). Trypsin activity in duodenal chyme 60 and 120 minutes after feeding was 2249±118.6 and 2368±122.1 U/L, respectively, indicating adaptation of the pancreas to the protein component of the feed. In blood serum, trypsin activity reached 298±59.9 U/L, which is 7.5 times lower than in the intestine, but indicates a high level of metabolism. Molecular genetic analysis confirmed the expression of the PRSS2 and PRSS3 genes in the duodenal contents and PRSS3 in the blood, with the activity PRSS3 in the blood was higher than in the intestine. A correlation was established between trypsin activity in biological fluids and metabolic processes, including protein and lipid metabolism. The results emphasize the role of trypsin as a marker of metabolism and its regulatory functions, which is important for optimizing diets and assessing the selection indicators of poultry.

When growing birds, instead of antibiotics, the use of biologically active drugs is increasing, which help to increase the resistance of the bird's body, their safety and increase the growth and development rates of young animals. The purpose of the research: to find out the effect of the probiotic drug "Vetom 1.2" and the multivitamin complex "Chiktonik" on the growth rate of quails of the Pharaoh breed and their safety, age dynamics of esophagus development. The experiment lasted 50 days, during which the first group of birds received the main diet (control), the experimental groups in addition to the main diet supplements of biologically active substances: the second - probiotic "Vetom 1.2", the third - a combination of probiotic "Vetom 1.2" and multivitamin complex "Chiktonik". The linear parameters of the quail body varied throughout the experiment in all groups, but the most stable indicators were recorded in quails that received the probiotic "Vetom 1.2" as a supplement to the main diet in combination with the vitamin-amino acid preparation "Chiktonik", while in individuals from the other two groups, abrupt changes in the growth rate were noted. In each decade of the experiment, the prevalence of morphometric parameters of the esophagus in birds of the experimental groups was recorded compared to the control, which indicates a positive effect of the additives on the development of the digestive system in birds, especially in the second experimental group. The survival rate of quails during the first week of life was 84.00%. Moreover, the highest survival rate of birds was also recorded in the second experimental group, which received the probiotic in combination with the multivitamin complex as a supplement to the main diet.

Mycotoxicosis continues to be an urgent problem in the agricultural sector, as mycotoxins are widespread as contaminants in feed and food products. The mold fungus of the genus Aspergillus secretes several types of aflatoxins (B1, B2, G1 and G2), of which aflatoxin B1 belongs to the group of particularly dangerous. Aflatoxin B1 exhibits tropism to hepatocytes, destabilizing the processes of metabolism and detoxification in the organ, and the development of pathological changes at the macro- and microscopic levels disrupts the basic functions of the liver, which in turn induces multiple organ failure. The purpose of this work is to study the effect of the preventive agent «Hepatoprotect» developed on the basis of the FSBSI «FCTRBS-ARRVI» on the preservation of the rat hepatocytes morphology in conditions of experimental aflatoxicosis. The object of the study was white rats, which were divided into 3 groups (6 heads each) according to the principle of analogues, taking into account weight, gender and age. The first group served as the biological control of the experiment. The second was a toxic control that received aflatoxin B1 with food. The third group was simultaneously given food contaminated with aflatoxin B1 and the «Hepatoprotect» dietary supplement. After euthanasia, liver samples were taken, which were examined at the histological and ultrastructural levels. The results of the histological examination demonstrated the positive effect of the feed additive «Hepatoproject» on the preservation of the rat liver histoarchitectonics in conditions of experimental aflatoxicosis. Based on the data of the ultrastructural study and their statistical processing, the protective effect of the feed additive «Hepatoprotect» against the mitochondria of white rat hepatocytes was also confirmed. The developed means of preventing mycotoxicosis contributes to the maintenance of cellular respiration processes, reducing the risk of hypoxia, leading to the mass death of hepatocytes.

The aim of this study was to evaluate the relative expression levels of genes encoding key antioxidant enzymes, namely superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), in calves with respiratory disease. Respiratory diseases are also characterized by an imbalance between pro-oxidant and antioxidant mechanisms. Developing oxidative stress exacerbates the disease course and can be used as a target for therapeutic intervention. To achieve this goal, quantitative real-time polymerase chain reaction was used, with peripheral blood from sick and healthy calves serving as the research material. Healthy 3-month-old calves (n=10) and sick (n=10) animals of the same age with respiratory disease were selected for the experiment. The results showed a statistically significant increase in HIF-1α gene expression in the blood of calves with respiratory disease, indicating activation of the hypoxic response. SOD1 gene expression was also increased, which may indicate a compensatory reaction to oxidative stress. Furthermore, GPX1 gene expression was elevated in sick calves, which may indicate enhanced hydrogen peroxide detoxification in response to increased production of reactive oxygen species. At the same time, CAT gene expression did not show statistically significant differences between the groups. Increased expression of HIF-1α, SOD1, and GPX1 in the blood of sick calves reflects the activation of compensatory mechanisms in response to hypoxia and oxidative stress. The lack of significant changes in catalase expression may indicate that, in the early stages of the disease, this gene is not involved in compensatory processes to a sufficient extent, or its activation occurs at later stages.

Currently, diseases of fur–bearing animals associated with the urinary tract of various ethologies are widespread, which affects the development of the entire organism, and as a result, the quality of the products obtained is deteriorating - fur. Without knowledge of the morphological features of the structure of the urinary organs in the age aspect, it is problematic to diagnose diseases and pathologies, as well as to carry out timely treatment. The aim of the study was to study the anatomical and topographic features of the course and branching of the renal arteries of males of the black Pushkin breed in the age aspect, as well as to determine their morphometric parameters. This will allow us to better understand the mechanisms of adaptation of the vascular system to specific conditions of detention and subsequently develop recommendations for optimizing the breeding conditions of sables. The object of the study was male sables aged 15-20 and 36-40 months from birth, with six heads in each group. To achieve this goal, a set of research methods was used: fine anatomical dissection, morphometry, photographing, vasorentgenography, manufacture of corrosive preparations, computed tomography. The study established the main arterial routes, as well as their course and branching of the renal arteries in male sables of the black Pushkin breed in the age aspect. The main dynamics of vascular diameter increase is observed by an average of 1.32 times in individuals at 36-40 months of life, compared with sables 15-20 months from birth. The established data demonstrate normal age -related changes in the vascular system characteristic of the growth period of young sables of the Pushkin breed. A 51% increase in the distance between the renal arteries and a 50% increase in the diameter of the aorta is a direct consequence of the overall increase in body size and the development of the vascular system. This ensures an adequate blood supply to growing organs by increasing the length of the vascular bed and the diameter of the main vessels to allow more blood to pass through. At the same time, the fundamental proportions and patterns of vascular branching are preserved (a constant coefficient of narrowing of the aorta after the departure of the renal arteries).

Fundamental data are of particular importance in surgical practice, since detailed knowledge of the anatomical features and patterns of the course and branching of the vascular bed is critically important for surgical manipulations in the head, neck, and spinal column, especially in the context of traumatic injuries. The aim of the study was to establish anatomical and topographic features of the venous bed of the rib–necked trunk in black-and-white calves and to determine morphometric parameters. The study was conducted at the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. Cadaveric material for the study was delivered to the Department of Animal Anatomy of the St. Petersburg State Pedagogical University from the pig breeding complex of the Leningrad region. The study used seven corpses of newborn calves of black and mottled breed aged 2-8 days from birth. During the study, anatomical and topographic features of the venous bed of the rib-necked trunk in calves of the black-and-white breed were established and morphometric parameters were determined. The venous bed of the ribnecked trunk in black-and-white calves is a highly organized and functionally adapted system. Its key importance lies in the active provision of an effective outflow of venous blood from the deep structures of the neck, shoulder girdle and upper chest. The presence of numerous, well-developed valves distributed according to the diameter of the vessels, the functional load of the drained muscles and the localization relative to the thoracic cavity is a vital adaptation. This venous system guarantees a reliable outflow to the heart, supports the metabolism of actively working muscles and ensures stable blood supply to a critical area of the animal's body, directly affecting its motor and respiratory functions.

As the amount of data on genomic variations increases, tools capable of assessing the functional impact of individual nucleotide sequences are becoming more relevant. There are several prediction servers available to interpret the effects of variants in the human genome, but few have been developed for other species, and none have been specifically designed for species of interest to veterinary medicine, such as dogs. [1] Mammalian glycopeptide hormone receptors are key regulators of reproductive development, and their homologues are widespread in the animal kingdom.[2]. The interest of our research group is aimed at finding gene variations promising for further research of associations in the field of dog reproduction. In this regard, a group of genes has been selected that potentially affect the sperm quality of males. Based on the GeneCards® human gene database, the following genes were selected: the INHBA (Inhibin subunit Beta A) gene, associated with the activation and inhibition of follicle-stimulating hormone by the pituitary gland, a protein encoded by this gene plays an important role in the development of eyes, teeth, and testicles [11], as well as the FSHR (follicle stimulating hormone receptor) gene, The protein encoded by this gene belongs to the G protein-coupled receptor family 1. It is a receptor for follicle-stimulating hormone and is involved in the development of the sex glands [11]. Mutations in this gene cause type 1 ovarian dysgenesis, as well as ovarian hyperstimulation syndrome in humans [11]. We hypothesized that the INHBA and FSHR genes may affect the quality of ejaculate in males. Studies in the field of INHBA and FSHR gene polymorphisms, which were included in this study, were previously conducted on sheep [3] and bulls [4].

Follicular fluid (FF) is a natural environment for oocyte maturation and can be used for these purposes in vitro. However, due to the seasonality of equine breeding, some follicles undergo luteinization or regression during the spring transition period, which can be directly related to oocyte quality in year-round use of mares in ART programs. In order to find diagnostic criteria for selecting FF for in vitro maturation and predicting the quality of mares' oocytes, a comparison was made between the biochemical and hormonal composition of FF in the spring transition period (group I, including normal (Ia) and luteinizing (Ib) follicles) and FF from large estrous follicles of cycling mares in the breeding season (group II), as well as in the blood serum (group III). Analysis of the content of biochemical components and steroid hormones in the FG showed no quantitative differences in most components in subgroups Ia and Ib, except for total protein (p=0.048) and alanine aminotransferase (ALT) (p=0.013). Significant differences in the content of serum iron (p=0.019) and phosphorus (p=0.005) were found in the FF obtained from mares in the spring transition period and in the season of sexual activity. The concentration of testosterone, dihydrotestosterone and progesterone significantly (2-4 times) increased in the FF of estrous follicles in the mating season. It was concluded that the concentrations of progesterone, testosterone and dihydrotestosterone, taking into account the content of phosphorus and serum iron, can serve as a criterion for selecting FF for oocyte maturation in vitro. The content of progesterone, dihydrotestosterone, testosterone should be at least 100 nmol/l, 1000 pg/ml, and 16 nmol/l, and phosphorus and serum iron content within 0.74-1.1 and 46.4-57.0 mmol/l, respectively. Using these parameters of follicular fluid as criteria will determine the feasibility of its use for oocyte maturation in vitro.

Целью исследований явилось изучение влияния производных МСК на переживаемость сперматозоидов быков-производителей. Количество собранных образцов составило 32. После взятия и оценки эякулята, проводили центрифугирование (600 оборотов – 7 минут), далее удаляли семенную плазму и проводили дальнейшее исследование по двум направлениям: 1. инкубация образцов (n=19) с со средой № 1 (кондиционированной средой МСК КМ быков (эксперимент № 1)); 2. инкубация образцов (n=13) Со средой № 2 (лизатом МСК КМ быков (эксперимент № 2)). При проведении 1-го эксперимента - инкубации образцов спермы быков-производителей со средой № 1, было зафиксировано непродолжительное время переживаемости (2 часа). При двухчасовой инкубации образцов в данной среде наблюдалось выраженное снижение количества прогрессивно двигающихся сперматозоидов в опытной группе в 2,6 раз (p≤0,05), в контрольной группе - в 4,7 раза (p≤0,05) по сравнению с показателями 0 часов инкубации. Достоверное снижение количества нормальных форм сперматозоидов было зарегистрировано при оценке 2-х часовой инкубации спермы в опытной и контрольной группах в 1,1 раз (p≤0,05). Полученные данные указывают на низкую эффективность применения кондиционированной среды в аспекте улучшения качества спермы. На втором этапе исследований (эксперимент № 2) была проведена оценка эффективности применения среды № 2. При инкубации образцов в данных средах была зафиксирована четырехчасовая переживаемость сперматозоидов, анализ показателей подвижности и морфологии которых указывает на положительное влияние данных производных МСК на функциональную способность клеток, при этом на 4-й час инкубации количество прогрессивно подвижных сперматозоидов составило 41,25±13,3%, количество морфологически нормальных сперматозоидов – 62,13±2,56%.

Postpartum paresis is a widespread disease of dairy cows, occurring in industrial animal husbandry and in private farms. Postpartum paresis is registered under conditions of intensive dairy farming in all countries of the world. However, despite its wide distribution, its etiology and pathogenesis remain insufficiently studied. The aim of the study was to analyze biochemical changes in the blood serum of cows with postpartum paresis. Object of the study - blood of calving cows with signs of postpartum paresis and without pathology of the postpartum period as a control. The object of the study was blood serum from the jugular vein. The material was collected in vacuum tubes 1-2 days after calving. The study was carried out in the Omsk region “Omsk regional veterinary laboratory” on an automatic biochemical analyzer BioLit-8020. Statistical processing of the study results was carried out using Statistica 13.0 program (StatSoft Inc, USA). The parametric Student's t-criterion for independent samples was used for comparison of intergroup indices. The correlation between alkaline phosphatase and calcium concentration was established using the Kendall-Tau criterion. The study revealed statistically significant changes in the content of total protein (p = 0.006), globulins (p = 0.031), calcium (p < 0.001), creatinine (p = 0.012), and alkaline phosphatase activity (p = 0.041). The relationship of the studied indicators with the violation of phosphoruscalcium metabolism is reflected. The decrease in functional activity of kidneys and liver deserves special attention, which should be taken into account in the development of therapeutic and preventive measures.

Determining the follicular phase of the estrous cycle is a critical task for successful artificial insemination, embryo transplantation, and egg washing in cows. The existing methods for determining this period are not ideal and have a number of limitations. Laboratory diagnostics plays a key role in modern animal husbandry. Monitoring of reproductive status, monitoring of metabolic processes, and assessment of feeding quality are critical control points during both routine medical examinations and specialized examinations of high–value animals. For the most part, reproduction control may consist in determining progesterone levels, diagnosing anestrus, and identifying the most optimal time for insemination. One of the markers of routine assessment of reproductive status may be the anti-muller hormone. Determining the level of anti-Muller hormone (AMH) seems to be a promising tool for monitoring reproductive status, especially in large herds, however, additional study of this hormone is required for a more accurate understanding. In the presented study, the biochemical parameters of the blood of 9 Holstein cows in the follicular phase were analyzed. A high degree of direct correlation was found between the AMH level and serum creatinine and phosphorus levels (0.75 and 0.78, respectively). An inverse correlation of a noticeable degree (-0.63) was found between the level of AMH and the level of serum AsAt activity. The study of the synthesis, regulation and metabolic effect of AMH continues, data on its relationship with other regulatory factors are limited. Additional research is needed to better understand this correlation and its significance.

The ability to activate platelets isolated from blood samples stabilized with sodium citrate, EDTA or heparin and located in plasma containing the same anticoagulant was studied. Platelets found in plasma were induced to activate in vitro by adding agents such as epinephrine, thrombin, or thrombin+thromboxane-A2. The ability of platelets to form aggregates, which were microscopically visualized in phase contrast, was used as an activation marker. The studies showed that platelets isolated from blood samples stabilized with any of the abovementioned anticoagulants did not aggregate in response to the addition of adrenaline. Platelets isolated from blood stabilized with sodium citrate and EDTA retained the ability to aggregate after plasma recalcification, but did not aggregate in response to the addition of thrombin. However, platelets isolated from sodium citrate-stabilized blood, unlike platelets isolated from EDTA-stabilized blood, aggregated in response to the addition of thrombin along with thromboxane-A2. Platelets isolated from heparin-stabilized blood were moderately aggregated for thrombin activation and very strongly for thrombin + thromboxane-A2 activation. The results of the study obtained in an in vitro model indicate that platelets isolated from blood samples stabilized with sodium citrate or EDTA, after their introduction into the patient's tissues as part of plasma containing the same anticoagulant, will be able to activate and realize their regenerative potential only under the condition of rapid recalcification. And platelets obtained in the form of plasma enriched with platelets from heparinstabilized blood samples will be able to activate and realize their regenerative potential only if the injected anticoagulant does not interfere with the processes of plasma and platelet hemostasis at the injection site and, accordingly, the synthesis of thrombin and thromboxane-A2.

A decrease in testosterone slows down muscle growth, but at the same time, fat layers are deposited in the meat in the form of a pattern, it becomes softer, has better taste characteristics and does not have a specific smell. The aim of the research is to provide a comparative assessment of the effectiveness of castration of bull calves using two bloodless methods: using a Callicrate smart band elastrator and Burdizzo forceps. The experiment was conducted on Aberdeen Angus calves kept on the Golubcha farm of Bryansk Meat Company LLC, located in the Trubchevsky district of the Bryansk region. Two groups of bull calves aged 12 to 15 months were formed. The calves of the experimental group were castrated with Burdizzo forceps. The bulls of the control group were castrated using a Callicrate smart band elastrator. In the experimental group, 20% of the animals had complications of varying severity. The most common types of post-surgical complications were skin wounds and inflammatory edema, purulent necrotic processes in the scrotum. Almost all calves neutered with forceps had inflammatory edema of varying severity, which subsided after 10-13 days. In the control group, complications were noted in 16.25% of animals. The cause of the complications was damage to the skin of the scrotum at the site of the adhesion ring, followed by the development of a wound infection. Incomplete tightening of the elastic band led to partial preservation of testicular nutrition. In such animals, venous congestion and increased soreness in the tissues of the scrotum and testicles were observed, and edema persisted for more than three weeks. The rupture of the elastation ring and its loss caused a delay in the loss of the mummified scrotum with testes and the development of inflammatory processes with the proliferation of pathological granulation tissue in the stump area.

The aim of the study was to study the preventive efficacy of the probiotic supplement "GidroLaktiV" and to establish its effect on the formation of the intestinal microbiome in calves with neonatal gastrointestinal diseases. The object of the study was healthy newborn calves that did not have clinical signs of hypotrophy. From the selected calves, according to the principle of analogues, taking into account body weight and physiological condition, two groups were formed – the control and the experimental. Each of the groups included ten animals. The animals of both groups were kept in identical conditions on a basic diet adopted by the farm for raising young animals. From the fourth day of life until the age of forty, calves of all groups were given kefir prepared using the enzymatic feed additive "GastroVet" according to the scheme adopted in the experimental farm. Additionally, the feed additive "GidroLaktiV" was added to kefir to the calves of the second experimental group at a dose of 15.0 g per head twice a day. In the case of clinical signs of gastrointestinal diseases in the studied animals, primarily manifested by dyspepsia, they were treated according to the scheme used in the farm. The last one included: "Coliflox" at a dose of 2.0 ml / goal / day; "Sulfetrisan" at a dose of 3.0 ml / goal / day; 9-valent serum (Uralbiovet), once at a dose of 50.0 ml / goal. The treatment was carried out until the clinical signs completely disappeared. In order to assess the degree of influence of the additive used on the composition of the intestinal microflora, stool samples were examined using a bacteriological method. The conducted studies have shown high preventive effectiveness from the use of the probiotic supplement "GidroLaktiV", which is characterized by a decrease in the incidence rate and a shortening of the recovery time. The supplement used has a positive effect on the formation of the intestinal microbiome of calves. This is manifested by a decrease in the amount of E. coli and staphylococcus in its composition, which indicates its antagonistic activity to conditionally pathogenic flora, as well as an increase in the level of lactobacilli.

A full-fledged diagnosis of pneumonia should include testing for the level of acutephase inflammatory proteins. C-reactive protein is widespread in dogs, and its concentration increases as early as 6-8 hours after the onset of inflammation. Cats have serum amyloid A, whose concentration increases 24-48 hours after the onset of inflammation. Currently, the immunofluorescence method is widely used to determine acutephase inflammatory proteins. The authors compared the levels of acute-phase inflammatory proteins in healthy animals and sick animals (before and after treatment). A statistically significant difference was revealed between patients before treatment and healthy animals. A statistically significant difference was found between recovered and healthy cats. There were no statistically significant differences between recovered and healthy dogs. The level of serum amyloid A in sick cats significantly increased 8-fold relative to healthy ones (p<0.01), and upon recovery returned to the standard values, but was significantly higher by 32.6% than in healthy animals (p><0.01). The level of Creactive protein in sick dogs significantly increased by 7.6 times relative to healthy dogs (p><0.01), and upon recovery returned to the standard values and had no significant difference with healthy animals. Determining the concentration of C-reactive protein in dogs and serum amyloid A in cats before starting therapy and after antibiotic therapy helps to decide whether to extend treatment if necessary and is one of the criteria for the success of therapy. > < 0.01), and upon recovery returned to the standard values, but was significantly higher by 32.6% than in healthy animals (p < 0.01). The level of Creactive protein in sick dogs significantly increased by 7.6 times relative to healthy dogs (p < 0.01), and upon recovery returned to the standard values and had no significant difference with healthy animals. Determining the concentration of C-reactive protein in dogs and serum amyloid A in cats before starting therapy and after antibiotic therapy helps to decide whether to extend treatment if necessary and is one of the criteria for the success of therapy.

The digital flexor tendons bear enormous strain in sport horses of all types. In sport horses, the most common injuries are to the tendons of the deep and superficial digital flexors, which is the cause of both temporary and recurrent or permanent chronic lameness and in many cases leads to the end of a sports career or the transition of the horse to amateur sports. Tendons have a very slow regeneration rate, and normal tissue is replaced by fibrous tissue. Fibrosis, scars, contractures and other chronic pathologies are quite common consequences of acute diseases and injuries. Classical methods of therapy of degenerative pathologies of limb tendons include: tenotomy, orthopedic shoeing and physiotherapy. Physiotherapy is the most effective method of treatment and rehabilitation for fibrosis and other degenerative pathologies of the tendons of the horse's limb. Such methods as shock wave, laser and magnetic therapy, the introduction of platelet autoplasma, etc. are already successfully used in veterinary medicine and have proven their effectiveness. One type of physiotherapy that can be used in therapy is iontophoresis. The aim of the study was to identify the clinical effectiveness of iontophoresis with the drug "Fermencol" under different protocols of procedures. The study was conducted on 8 heads of horses. In total, each horse underwent 3 courses of iontophoresis. The results were recorded using ultrasound. In 6 heads, the tendon diameter returned to normal values (<1.5 cm) by the end of the third course of procedures. The use of iontophoresis with the drug "Fermencol" has a positive effect on fibrotic tissues of the flexor tendons of the thoracic limbs in horses. Also, this method of therapy has a number of advantages over the commonly accepted ways.><1.5 cm) by the end of the third course of procedures. The use of iontophoresis with the drug "Fermencol" has a positive effect on fibrotic tissues of the flexor tendons of the thoracic limbs in horses. Also, this method of therapy has a number of advantages over the commonly accepted ways.

Calf diarrhea is one of the most common diseases worldwide, causing serious economic losses to the livestock industry. The costs of the disease are not only due to the short-term costs associated with treatment and mortality, but also the long-term consequences such as reduced weight gain and negative impact on the overall productivity of the herd in the future. This emphasizes the relevance of developing effective methods of prevention and therapy of diarrhea in newborn calves. The aim of this study was to investigate the effect of a laboratory sample of biologically active composition of microbial origin (BACMP) based on Medusomyces gisevii culture medium and polysaccharide on newborn calves with signs of acute diarrhea. Vinegar bacteria and yeast included in the BACMP culture medium have pronounced probiotic properties, contributing to the restoration of the balance of intestinal microbiota. Studies were conducted on Holstein calves (n=92), with clinical signs of acute diarrhea: liquid, mushy feces of yellow color; oppression of general condition; decreased or complete lack of appetite. Calves of the experimental group (n=45) were orally administered symbiotic at a dose of 30-40 ml per head for 5-7 days, depending on the severity of clinical signs. According to the results of the study, during which the experimental group received symbiotic and the control group - antibiotic and multivitamin preparations, no statistically significant differences in the indicators of biochemical, general blood analysis and immunologic study were revealed. Recovery of clinically sick calves, according to the results of our observations, in both groups came on the 6th day of treatment.