The effectiveness of aminoglycoside antibiotics, paromomycin, for cryptosporidiosis in calves was determined based on the results of a coprological study and an assessment of the physiological state before and after the treatment of the animals. Calves with signs of diarrhea, dehydration, cachexia, and were later diagnosed with cryptosporidiosis, were given the drug «Protostop» orally, containing 100,0 mg of paromomycin sulfate in 1,0 g. The animals were separated into 5 groups, 10 calves in each: four experimental and one control. Animals from groups № 1 and № 2 were given the drug «Protostop» orally, at a dose of 250 mg per 1 kg of the animal’s weight, in a course of 3 and 5 days, respectively. The animals in groups № 3 and № 5, the drug «Protostop» was given orally at a dose of 350 mg per 1 kg of the animal’s weight, in a course of 3 and 5 days, respectively. Calves in the control group (№ 5) underwent therapy with an analogue drug, «Parofor 70». After administration of the drug «Protostop» orally with liquid for 3 days at a dose of 250 mg per1 kg of the animal’s weight (group №1), as well as at a dose of 350 mg per 1 kg (group № 2), significant improvements were noted, which confirmed the results of scatological studies, but Cryptosporidium oocysts continued to stand out. Cryptosporidium oocysts were not detected, after the introduction of the oral drug «Protostop» for 5 days at a dose of 350 mg per 1 kg of animal weight (group № 4). In samples of feces from calves of the control group (№ 5), which received therapy with the drug «Parofor 70», single oocysts of Cryptosporidium werefound after a 5-day course of treatment.

Coccidiosis is the most common disease in rabbits, causing great economic damage in rabbit farming. The aim of this work was to study the effect of coccidia on the parameters of the micronucleus test, since the authors did not come across data on the study of the mutagenic effect of Eimeria metabolites on the chromosomal apparatus of somatic cells in rabbits in the literature. For the experiment, 4 groups of rabbits, 10 heads each, with high, medium, low intensity of invasion (II) by oocysts of coccidia and healthy animals were formed. In experimental and control rabbits, blood was taken from the marginal ear vein, smears were prepared and stained with Giemsa dye. To carry out the micronucleus test, microscopy of blood preparations was performed and the frequency of occurrence of erythrocytes with micronuclei was calculated. It was found that in rabbits with low IS, the frequency of occurrence of erythrocytes with micronuclei was 1.49 + 0.10, which was 1.6 times higher than that of the control group (p <0.001). In the group of rabbits with medium IS, the frequency of appearance of erythrocytes with micronuclei was 2.3 times higher than in the control group (p <0.001) and was 2.15 + 0.09. The frequency of occurrence of erythrocytes with micronuclei in the group with high IS exceeded the control indicator by 3.1 times and amounted to 2.88 + 0.13 ‰.
According to the results of laboratory studies, it was found that the change in the frequency of occurrence of erythrocytes with micronuclei in the peripheral blood of rabbits depends on the degree of invasion by eimeria, thereby proving the mutagenic effect of eimeria metabolites on the chromosomal apparatus of the host somatic cells.

The problem of the spread of bacterial infections of birds associated with opportunistic microorganisms occupies a significant place in the modern infectious pathology of birds.
The aim of this work is to determine the species diversity of the dominant etiologically significant bacteria circulating in industrial poultry farming. Based on the results for the period 2019 to 2020, we carried out bacteriological studies of pathological material from birds in poultry farms of various technological directions.
The dominant species are Escherichia coli, which accounts for 50.7%, Enterococcus faecalis - 25.4%, and Proteus mirabilis - 8.4%. Also, thermophilic Campylobacter spp. - 4.3% were isolated from the organs, including such epidemiologically dangerous species as Campylobacter jejuni. The microorganisms were virulent and differed in their cultural and biochemical properties.
Cultures such as Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus faecalis are isolated from many organs, which indicates the generalization of the infectious process, the culture of thermophilic Campylobacter spp. were isolated from the liver, which indicates the organotropy of these types of microorganisms.
The species composition of the allocated microflora is determined by the epizootic situation in each individual farm, which results in a different percentage of the dominant species.
Pure cultures of thermophilic campylobacter were obtained on selective Preston agar with cultivation for 7 days at a temperature of 42 ° C under microaerophilic conditions. However, culturing Campylobacter hepaticus is difficult because it is sensitive to a number of antimicrobial agents used in Campylobacter enrichment media and selective agar.
The emergence of new Campylobacter species requires a revision of phenotypic identification algorithms. MALDI TOF mass spectrometry databases need to be updated and specific primers developed to identify new Campylobacter species.
Significant variability of indicators of indication of one or another microflora from the liver and gallbladder indicates significant differences in the etiology of bacterial infections of birds.

This work is devoted to an experimental study of the reaction of body tissues to an implant based on bacterial cellulose synthesized by the bacterial strain Gluconacetobacter xylinus. The influence of the internal environment of the body on the characteristics of the implanted material was also studied to determine the prospects for its use in veterinary medicine.
Currently, the issue of creating new implantable materials for a long time, or improving existing ones, does not lose its relevance. Based on this, it can be concluded that there are shortcomings in the previously developed materials. Certain requirements are imposed on implantable materials, such as elasticity, strength, porosity, non-toxicity, and others. The most important property of such materials can be called biocompatibility, as well as resistance to the effects of the biological environment.
This study is aimed at establishing the possibility of using bacterial cellulose (BC) as an implantable material, which combines all the necessary properties for implants. The study of the reaction of body tissues to the implant was carried out on laboratory rats of the Wistar line. The implanted material was placed on the outer layer of the muscles of the abdominal wall of laboratory animals, after which, on the 14th, 30th and 90th days, a visual examination of the state of cellulose and nearby tissues was carried out, and tissues were selected for histological examination.
The experimental results indicate that the implant based on bacterial cellulose does not cause negative reactions from nearby tissues, does not collapse during the observation period, and is reliably fixed on the muscle layer by a capsule of collagen fibers.

Today, fur farming continues to incur huge losses because of the Aleutian mink disease. Frequently, the pathogen enters the territory of farms together with newly imported mink livestock, which is why the applied immunoelectroosmophoresis reaction has low efficiency if the antibodies have not yet reached a certain level. So for this reason, the problem of accurate and early diagnosis of viral plasmocytosis in newly imported quarantine livestock becomes urgent. The study was carried out using PCR diagnostics of fecal samples from a newly imported population of minks of 30-day age in the fur farm of the North-Western region. Before taking fecal samples, all animals were examined by clinical methods. PCR diagnostics was performed using a set of reagents «Test system "ABN"» according to the manufacturer's instructions. According to the results of the experiment, it was found that out of 40 selected animals without clinical signs of the disease, 29 managed to detect the DNA of the causative agent of viral plasmocytosis. Thus, the use of PCR diagnostics as a method of identifying the Aleutian mink disease virus for newly imported livestock will prevent the development and spread of the disease already at its early stages.

Infectious bursal disease (IBD) virus is the causative agent of a severe immunosuppressive disease in young birds. Although the disease was first discovered more than 60 years ago, it continues to pose a significant threat to the poultry industry worldwide [4]. The causative agent is RNA-containing virus, which belongs to the genus Avibirnavirus of the family Birnaviridae [17].
The virion includes five viral proteins, designated VP1, VP2, VP3, VP4, and VP5 [15] with an approximate molecular weight of 97 kDa, 41 kDa, 32 kDa, 28 kDa, and 21 kDa, respectively. Additional proteins such as VPX or pVP2 are also noted [12].
The capsid protein VP2 has long been a focus of recombinant subunit vaccine development because it is responsible for eliciting a protective immune response against IBD. However, reports of many authors [2,3,6] point to the antigenic heterogeneity of IBD virus strains isolated in Russia and other countries, which is associated with the failure of existing vaccines in preventing the disease; therefore, to create and successfully use recombinant vaccines, it is necessary to study epizootic strains isolated in the Russian Federation as well.
Therefore, the purpose of this work was to perform genetic analysis of the VP2 gene of the epizootic strain "Sinyavinsky" and compare it with the classical strains of IBD virus serotypes 1 and 2 isolated in Europe and highly virulent strains isolated in the Russian Federation.

This article analyzes the epizootic situation of leukemia of beef and dairy cattle in the farms of the Smolensk region. Laboratory diagnostic blood tests, which revealed infected and sick animals over certain years, played an important role in the study of the epizootic situation.
Along with this, we have studied the manifestation of the epizootic process of bovine leukemia in the Smolensk region. All this was later used to carry out effective work on the prevention and control of bovine leukemia.
The analysis data given in this article allow us to conclude that the disease of bovine leukemia in the region is gradually decreasing, and from 2017 to 2020 there is a more active decline. The most favorable epizootic situation for leukemia is in breeding and commodity farms for the cultivation of cattle. At the same time, the veterinary service is actively working to eliminate leukemia among cattle belonging to the population. Diagnostic studies on hematology to identify sick animals with leukemia have declined markedly, especially in recent years. This is due to both a decrease in the number of livestock and the elimination of the disease in many farms.
The livestock of cattle is annually subjected to routine serological studies, while the discharge of infected animals is still noted. As a result, there is a source of infection in the territory of the region among animals susceptible to it and the epizootic situation for leukemia among cattle remains unfavorable.

This article describes the results of an experiment on potentiation of the hepatoprotective agent "Hepaton" with a drugantagonist of CGPR receptors.
Calcitonin Gene Linked Peptide (CGRP) is a highly efficient vasoactive peptide released from sensory nerves, the main, most active form of which (α-form) is produced by alternative splicing. The CGRP receptor is a complex of a calcitonin-like receptor (CLR) and one transmembrane protein, RAMP1.
At the moment, one of the most urgent topics is the study of the role of this peptide in various pathogenetic processes in humans and animals. Due to the fact that the liver is one of the largest reservoirs for CGRP receptors, the role of this peptide in the regulation of liver pathologies is obvious. Thus, it has been reliably established that in hepatopathies of various origins, the concentration of CGRP in the blood plasma increases significantly, which determines the hyperkinetics of the portal circulation characteristic of liver lesions.
To assess the prospects of potentiation of hepatobiliary protector drugs using CGPR receptor antagonists, we used a drug with hepatoprotective activity "Hepaton" (developed by FGBOU VO "SPbGUVM", therapeutic dosage for rats - 0.5 mg / kg, duration of pharmacological correction - 7 days) in combination with monoclonal antibodies of class G2 (IgG2), binding with high affinity to the receptor of calcitonin-gene-related peptide (erenumab, Irinex, dosage for rats - 0.75 ml / kg, was used once before the start of the experiment) and their effect on the regeneration of hepatic pathology induced by the use of 1,2-dichloroethane (within 7 days) in standard dosages.
Based on both experimental and scientific literature data, it can be concluded that drugs antagonists of CGPR receptors have an extremely wide range of applications in the future, including for potentiating other drugs used for pharmacological correction of various pathologies.
Rational influence on CGPR receptors can reliably influence the maintenance of homeostasis and nociception of the hepatobiliary system.

Diseases of the hepatobiliary system occupy a leading position among diseases of non-contagious etiology in animals. Hepatopathy of various origins cause significant economic damage to livestock farms due to a decrease in overall resistance, a decrease in productivity, as well as an increase in the cost of both therapeutic and preventive measures. The prerequisites for an increase in the number of cases of such diseases are mainly violations of the conditions of keeping and feeding animals.
Bile acids are increasingly being evaluated as complex metabolic integrators and signaling factors for various metabolic disorders. Increased attention to bile acids as metabolic regulators has led to two main research questions: how do bile acid dominants change in metabolic diseases and how can the activity of bile acids be used to treat metabolic diseases? Both issues will be addressed in this review. We searched for original studies in the scientific databases PubMed, Elsevier Science (Scopus) and Clarivate Analytics (Web of Science) to identify the biochemical, signaling and target functions of bile acids, after which a formalized content analysis of the found publications was carried out. In recent years, much attention has been paid to bile acids, not only as the end products of cholesterol metabolism and the main components of bile, but also their role in a number of pathological conditions of the body. Thus, the data obtained by various researchers show that they can be markers of differential diagnosis between hepatopathy of various origins, which makes them one of the most promising diagnostic models.

In the present publication we share the results of our research into the effect of ofloxacin, a fluoroquinolone class drug, on leukocyte indices of Hisex Brown male chicks. We studied the indices in 2 groups: I – control group, which received pure drinking water, II – experimental group, which received ofloxacin via drinking water at concentration 200 mg/L for 10 consecutive days. Blood samples were drawn at Day 1, Day 3, Day 5, Day 7 and Day 9 after the drug withdrawal. We performed WBC differential for all the employed chicks; then by applying computational method we studied the dynamics of Krebs index (KI), leukocyte index (LI) and index of immunoreactivity (IIR). We observed a transitory decrease in KI by 25% on Day 3 and an increase in LI by 23% on the same day. These reliable changes occurring only once show that ofloxacin did not have a marked negative effect on these indices. We also observed a shift in IIR, here the dynamics was ambiguous. Accordingly IIR increased reliably by 47% on Day 1 as compared to control, but on Day 5 and Day 7 it decreased by 41% and 54% respectively. We noted continuous dynamics in IIR on Day 1, Day 5 and Day 7 but on the final day of the experiment, at the close, there were no reliable changes and that proves, with high probability, the absence of any negative effect of ofloxacin, when administered at concentration 200 mg/L, on physiological state of Hisex Brown chickens at young age.

The fish liver is an important organ involved in the complex metabolism of bile and bile acids. The biochemical reactions that occur during this process directly depend on the functional state of the digestive system and fish nutrition. Knowledge of the features of bile acid metabolism will allow designing the cheapest and at the same time effective drugs for the pharmacological correction of hepatopathy. The composition of bile acids depends on the type of food, so in fish such as pike, perch, carp, cholic and deoxycholic acids conjugated with taurine are more common. In predatory fish, cholic acid predominates, in contrast to benthivorous fish. Substances secreted with bile do not participate in the general metabolism of tissues, so that hepatocytes do not need to constantly secrete large volumes of bile.
The metabolism of bile acids is carried out by the liver and is called the enterohepatic circulation. It all starts with the biological precursor of bile acids - cholesterol. Cholesterol in the body is formed during the absorption of lipids in the intestine. Two-thirds of exogenous cholesterol is excreted from the body in the form of bile acids. As a result of transformation by hepatocytes, primary bile acids are formed - cholic and chenodioxycholic. Then they are cojugated with taurine or glycine in the C-24 region of the carboxyl group and are excreted from hepatocytes continuously through the bile ducts to the gallbladder and further to the intestine. In the intestine, under the influence of microbial metabolites, they are hydroxylated and converted into secondary bile acids. Cholic becomes deoxycholic, and chenodisoxycholic becomes lithocholic. A small amount of bile acids are in a free state and form paired compounds. 90% of bile acids in the intestine form complexes of choleic acids in combination with fatty acids, which are absorbed through the wall of enterocytes. In enterocytes, these complexes again disintegrate and bile acids again enter the liver through the portal vein. Thus the circle of metabolism is closed.

The paper presents studies on the therapeutic efficacy of the drug mastomycin in serous -catarrhal mastitis of cows. The drug contains: gentamicin sulfate, clindomycin and prednisone.
Experimental studies were carried out in the laboratory of the Institute and in CJSC named after. Michurin, Smolensky district, Smolensk region in the pasture period on lactating cows.
The mammary gland of lactating cows is constantly functioning, while it and the body as a whole are affected by adverse environmental factors: unsanitary conditions with an abundance of conditionally pathogenic microflora, disruption of the rhythm of the milking machine, etc. All this reduces the overall resistance of the body, and leads to the disease mastitis. Mastitis causes significant economic damage to the economy: they reduce annual milk yields and lead to premature culling of high-yielding cows.
In many farms, the treatment of mastitis is carried out for a long time (over three years) with the same drug, which creates conditions for the emergence of resistant strains of microorganisms.
The incidence of cows with mastitis according to statistics in the farms of the region remains high, with a subclinical form from 30 to 50% of the herd, with a clinical manifestation from 8 to 20%. Mastomycin was used for the first time on the farm for the treatment of mastitis, 82.3% of cows recovered during the three-day course of treatment, which is 23.6% higher than from the premolact used for a long time on the farm.
The results of the performed studies indicate the high therapeutic effectiveness of the mastomycin newly used in the farm.

In this study, the influence of various cryoprotectants on the viability of the consortium of probiotic microorganisms Lactobacillus plantarum 8β and Bifidobacterium adolescentis 17-11β after the lyophilic drying. These strains are manufacturing strains and are used for preparing feed additives. A total of 6 different protective environments were tested. The basis of all tested cryoprotector media was skimmed milk in a quantity of 10%, as cryoprotectants also used sucrose, lactose and SiO₂, which were added to the skimmed milk in various combinations. Lyophilic drying was carried out according to standard procedure, with preliminary freezing of samples in cryostat up to minus 72ºC, the lyophilization process lasted 26 hours, during which the vacuum index varied from 40 Pa to 4 Pa, The temperature was raised to 28ºC. The effect of the protective medium on the survival of probiotic microorganisms was determined by planting a series of crops on agar MRS-4, incubation at 37ºC in 48 hours, and then counting the colonies. Crops were produced before the drying procedure (the number of colonies was 100%) and immediately after. The highest survival rates of probiotic bacteria were obtained using a protective medium based on 10% skimmed milk and 10% skimmed milk with 2% SiO₂ added, accounting for 81.84% and 82.48% respectively. The moisture content of the samples after drying was as follows: Medium based on 10% skimmed milk - 4.40%; 10% of skimmed milk plus 2% SiO₂ - 4.93%. This humidity for lyophilic preparations of these bacteria is optimal, and promotes long-term storage of samples with continued viability.

To date, there is no registered injectable dosage form of levocarnitine for veterinary use on the territory of the Russian Federation. The purpose of our work was to conduct preclinical studies of l-carnitine for veterinary use, in particular acute toxicity, in laboratory animals and to establish the class of acute toxicity. Acute toxicity studies were conducted on outbred rats in October 2021 at the vivarium of the St. Petersburg State University of Veterinary Medicine. When studying acute toxicity after intragastric administration, l-carnitine was administered at an initial dose of 2 ml / kg of animal weight. When studying acute toxicity after intramuscular and subcutaneous administration, lcarnitine was administered at an initial dose of 2 ml / kg of animal weight. During three days of observations, the death of animals was not revealed. After the expiration of three days, we introduced the drug in the same dose and by the same routes of administration to other animals (three animals for each route of administration). During 14 days of observation, the death of the animals was not detected, other disorders of the general condition and any signs indicating the toxic effect of the studied drug were absent. As a result of acute toxicity studies on laboratory animals of the drug l-carnitine for veterinary use with intragastric, subcutaneous and intramuscular administration, it was found that a dose of 2 ml/kg did not cause death of experimental animals. The investigated drug l-carnitine, according to GOST 32644-2014, can be classified as hazard class V in accordance with the globally agreed system of hazard classification and labeling of chemical products or in class V in accordance with the toxicity classification according to Hodge and Sterner.

Due to the annual growth in the number of domestic and neglected carnivores (dogs and cats), conditions are created for the wide spread of parasitic infestations. The aim of our research was to determine the extensiveness of the invasion of dogs and cats by otodectosis in the districts of St. Petersburg and to study the effectiveness of the OKVET preparation developed by LLC NVC Agrovetzashchita in otodectosis of cats. To achieve the goal, 98 dogs and 109 cats were examined, in which scrapings from the outer and inner surface of the auricle were examined. It was found that the extensiveness of invasion (EI) in all examined cats and dogs was 17.8%. At the same time, EI among cats is 16.4%; dogs - 1.4%. To study the effectiveness of the OKVET preparation, the animals were divided into 3 groups of 8 cats each with a confirmed diagnosis of otodectosis. On the day before the use of the drug, more than 10 live mites were found in scrapings in all phases of development, as well as eggs of Otodectes cynotis in one p.z. microscope (magnification 10 X 10). On the 28th day after the application of the drug, the presence of no more than two live ticks in the adult phase and eggs in one p.z. was noted. microscope. Efficacy of the drug was 91.6% at a dose of 1 pipette of 0.5 ml per animal, with a weight of more than 8 kg - 2 pipettes of 0.5 ml, twice with an interval of 10 days.

The efficiency of the horse, high sports results and the effectiveness of recovery after stress, are largely dependent on the characteristics of the organization of nutrition and diet. The comparative assessment of the performance traits and the speed of recovery after workloads in the Oryol trotterhorseis presented in this work. Six horses were each fed diets of hay and cereal grains (HG), hay and combination of cereal grains and compound feed (HGM) in a 2 x 2 Latin-square design study. The performance was assessed by heart rate (HR) indicators using a Polar M400 monitor with an H10 heart rate sensor. Recovery of the heart rate to 80 beats / min after medium work (the average heart rate to 120 beats / min) at HG and HGM horses had no statistically significant differences. Recovery of heart rate to 60 beats / min in the HGM was significantly faster (P <0.05) than in the HG. Under intense workloads (average heart rate above 120 beats / min, or at least 5% of work at a heart rate of 180 beats / min or more), the HGM showed a significant (P <0.05) faster recovery of heart rate values after work than in horses HG. In the course of the study, it was also found that the use of partial replacement of grain concentrates with specialized feeds allows us to reduce the volume of the ration and the total amount of concentrates without changing the structure of the ration.

Today, poultry farming is one of the most relevant branches of agriculture, as it provides products that meet consumer needs of buyers in terms of price and taste. In the conditions of the modern production process, the innovative developments of scientists are gaining increasing relevance and interest from the technological service of poultry enterprises. The most demanded are developments on the use of environmentally friendly, economically justified and effective solutions to improve the productive and reproductive qualities of poultry. At the same time, the hatchery is one of the key links in the young stock production chain and the further quantity and quality of the planting stock will depend on the efficiency of its work. The previously developed technology for the use of biostimulant solutions contributes to an increase in the number of hatched young poultry, which has been proven in previous studies. The purpose of this experiment is to determine the possibility of using meat obtained with the use of biostimulants in embryogenesis for the subsequent sale of the product on the counter for consumption without restrictions. The studies were carried out according to generally accepted methods, taking into account (TR CU 021/2011) for microbiological indicators "Ensuring the compliance of food products with safety requirements." As a result of determining the organoleptic, microbiological, chemical and histological parameters of meat in the control and experimental groups, it was established that it fully complies with the current regulatory documents and is a complete food product. On the basis of the foregoing, the safety of the resulting products was experimentally substantiated when using biological stimulants in turkey embryogenesis based on the results of the data obtained from the indicators of the veterinary and sanitary examination.

The ban on the use of antibiotic stimulators of poultry productivity, as well as the growing awareness of consumers in the field of food safety and poultry health, were an incentive for the introduction of alternative concepts for maintaining the health of the gastrointestinal tract, on the condition of which 70% of feed costs in the structure of the cost of production depend. We have summarized the results of our own research on the use of acidifiers through feed and water. It is shown that in order to select an effective dose of the drug, it is necessary to determine the acid-binding properties of the components (KSS), which differ significantly and if this is not taken into account, then adding an acidifier to compound feeds with low KSS can cause cloacitis. At the same time, on compound feeds with high KSS, the addition of an acidifier contributed to a decrease in the indicator by 20-36%, which led to an improvement in the microbiological balance in the gastrointestinal tract, an increase in the digestibility of protein, fat, fiber by 3.1; 2.1 and 4.9%, respectively. The use of nitrogen, calcium and phosphorus increased by 5.6; 4.1; 4.9%, and the productivity of broilers by 3.1% while reducing feed costs per unit of production by 4.21 and 7.38%, respectively, in physical and monetary terms. When using organic acids (KisOrg) through water (300 ml/t to pH-4.5) five times for three days in a row during the period of rearing repair young, the live weight of chickens and roosters increased by 1.92% and 2.6%, the uniformity by weight increased by 5.6% and 7.3%, respectively. The same mixture of acids, when applied three times through water in an amount of 350ml / t (pH 4.0) when growing broilers, contributed to an increase in live weight by 3.1% while reducing feed costs by 4.5%.

The aim of the research was to study the dry palm oil «Profat» effect on the young short-haired mink skins quality during the winter hair cover formation (OctoberNovember). The experiment was carried out on slaughter young animals in the Corporation «Saltykovsky fur farm» of the Moscow region. It was found that the introduction of a new vegetable fat source into the slaughter young animals diet in the amount of 0.75g per 100g of feed mixture provides an increase in the absolute and relative increase in live males weight of the experimental group by 80.4 g (2687.1 g vs. 2611.5 g in the control) and 3.1% (21.2% vs. 18.1% in the control), respectively. When assessing the internal organs condition of animals, no pathological changes in their development were detected. Based on the analysis of data on the size and quality of the slaughter young males skins, it was found that the inclusion of dry palm fat in the diet provides, in comparison with the control group, an increase in the skins area in the experimental group by 0.2 dm2 due to an increase in the proportion of skins of sizes 30 and > and 0-20 by 9.4% and a decrease in the proportion of smaller skins – 1 and 1+ by 9.4%, an increase in the size offset by 1.7%. The economic efficiency of using palm oil in the young mink diets during the formation of winter hair cover (OctoberNovember) amounted to 27.0 rubles per skin (in 2020 prices) at the drug cost 0.21 rubles.

Microbiological control of food products of animal origin consists of specific methods of analyzing raw materials coming into processing and finished products of animal origin. The purpose of microbiological control is to identify the degree of poor quality of the analyzed samples. Microbiological requirements for food products are regulated by the regulatory documents of the international level, which include state standards and technical regulations of the Customs Union and other regulatory documents of national status. The microbiological control techniques are used to assess the infestation and identify the species of pathogenic and opportunistic microorganisms in the isolation on different nutrient media. The given work is devoted to the analysis of pathogenic and conditionally pathogenic representatives of microflora developing on food stuff of animal origin which is important for the satisfaction of physiological fullness of the human organism. The main pathogenic and conditionally pathogenic microorganisms that develop on food products of animal origin are considered. So the work presents the analysis of gram-negative and grampositive anaerobic microorganisms developing on meat products. Types and forms of pathogenic microflora developing in raw milk and dairy products, poultry eggs, fish and fish products. As a result of development and reproduction of pathogenic and conditionally pathogenic microorganisms, microbiological spoilage of food products is observed, and sometimes it has a form of latent infection. Accordingly, identifying them is relevant in modern conditions, as some producers seek to enter the international market, so their products must comply with international requirements.

In the conditions of the milk production complex in the Voronezh region, where Holstein cattle are kept, studies were conducted to study the degree of injury to blood cells during its selection by various methods in healthy calves and with endogenous intoxication syndrome. In healthy animals, blood sampling by passive leakage does not affect the membranes of erythrocytes. When using vacuum systems, there are no visual signs (hemolysis) of cell destruction, but changes in their cytoskeleton occur with an increase in the sensitivity of membranes to negative pre-analytical factors. In animals with endogenous intoxication syndrome, there are explicit or hidden destruction of erythrocyte membranes, which are manifested by an increase in the content of extra-erythrocyte hemoglobin, the degree of physiological hemolysis, sensitivity to intra- and extravascular hemolytic factors. As a result, already when selecting blood samples by passive gravity, there is a risk of hemolysis, and when using a vacuum system, it is observed in most samples. Therefore, when examining sick animals, it is necessary to take into account the high probability of laboratory diagnostic error at the pre-analytical stage that occurs due to hemolysis of erythrocytes with hypersensitivity to extravascular cytolytic factors, including mechanical effects during blood sampling.

Pathologies of the thoracic limb are quite widespread among domestic and wild carnivores. The study of the features of the anatomical and topographic characteristics allows the most accurate and individual approach to the diagnosis, treatment and prevention of the musculoskeletal system. The common fox is currently widespread not only in fur farms and fur farms, but also as a companion animal. In this regard, in the past few years, many breeds of this species have appeared which to this day have not received sufficient attention from veterinary specialists. The material for the study was five corpses of the common Bastard fox breed, aged from two to four years, obtained during forced euthanasia from internal non-communicable diseases from private farms and clinics in St. Petersburg and the Leningrad Region. The study was conducted at the Department of Animal Anatomy, St. Petersburg State University of Veterinary Medicine. During the study, methods such as fine anatomical preparation and weighing were used. Muscles in the elbow joint of the Bastarad Fox include the triceps brachii, ulna, tensor fasciae forearm, biceps brachii, brachialis, brachioradialis, pronators teres and quadrate, and arch support. The muscles of the elbow joint are divided into one- and two-articular, that is, those that act on only one joint and those that simultaneously act on two joints with their contraction. Also, the muscles of the elbow joint are divided according to their functions into extensors, flexors, pronators, supinators and tensors. In the course of the work, the anatomical and topographic features of the muscles of the shoulder girdle of the bastard fox breed, as well as their weight characteristics, were determined.

Nonspecific cellular immunity is the defense line against the effects of environmental factors. Phagocytic activity of blood is an actual and informative parameter to evaluate analyzing the effectiveness of drugs and feed additives in animal and poultry husbandry. Fish farming is no exception – increasing the fish body resistance is an important and urgent task in order to improve and maintain the quality of the products obtained. The most priority aquaculture direction in Leningrad region is the rainbow trout breeding. In this regard, the development and evaluation of means to increase the productivity and resistance of fish is an urgent task for veterinary science. The purpose of the presented study was to evaluate the effect of the complex mineral feed additive “SmartBiotic” on the phagocytic activity in rainbow trout fingerlings. For this purpose, 3 pools were formed – in the first pool, the concentration of the studied additive was 0.15%, in the second pool, the concentration of the studied additive was 0.25%, in the third pool – the control group. Blood sampling was taken three times each month. In the blood, the number of leukocytes and the level of phagocytic activity were evaluated according to generally accepted methods. During the experiment, the beneficial effect of the studied additive on the phagocytic number and phagocytic index of the studied fish was revealed, and the best results were found in individuals contained in a pool with a concentration of 0.25% of the studied additive.

The morphology of the valvular apparatus of the heart in animals is currently a topical and especially important area of the anatomy of the cardiovascular system. The study of the morphology of heart valves, namely their anatomy and histology, in animals in species and breed aspect, expands the area of knowledge of veterinary cardiologists and allows you to select an individual approach to a particular animal in the treatment of heart pathologies.
The purpose of our study is to study the features of the histological structure of the semilunar valve of the pulmonary trunk of the heart of the Anglo-Nubian goat breed, as well as to establish the morphometric parameters of the histostructures of this area.
The material for the study was the corpses of goats of the Anglo-Nubian breed at the age of 12 months, obtained by slaughter from the farm "Gzhelskoe Podvorye" in the Moscow region of the Russian Federation.
Selected samples for histological examination were stained with hematoxylin, eosin, Trichrome according to Masson, toluidine blue and Schiff-iodic acid according to McManus.
As a result of the study, it was found that the cusps of the semilunar valve of the pulmonary trunk of the heart of the Anglo-Nubian goat breed are represented by the aortic (fibrous), spongy (spongiform) and ventricular layers. The aortic layer is formed by collagen and elastic fibers, the spongy layer is formed by loose small-celled connective tissue, and the ventricular layer of the cusps of the semilunar aortic valve is also formed by connective tissue and is much smaller than the aortic one. According to the results of histological examination, morphometric data for each layer of the valve are presented.

The article describes the results of the study of intranasal neoplasms in dogs, their clinical and morphological characteristics, describes the variants of clinical manifestations of oncological diseases at different stages of development. The predisposition of dogs of dolichocephalic breeds to the development of the tumor process was revealed. The possible sexual predisposition of nasal cavity pathologies has been studied. Possible causes of carcinogenesis of nasal cavity tumors, the nature of which includes a significant number of factors, have been investigated. Various morphological diagnoses of nasal cavity pathologies in dogs have been studied. Data on the spread of intranasal neoplasms in dogs are presented on the example of 34 clinical cases of animals of different age groups with pathologies of the nasal cavity, with pronounced clinical symptoms and without symptoms. Clinical symptoms in animals with nasal cavity pathologies were evaluated and compared. The influence of exogenous and endogenous factors on the development and growth of malignant tumors was studied. The degree of spread and invasion was determined using such visual diagnostic methods as magnetic resonance imaging and computed tomography, the general condition of the animal was assessed using general clinical and biochemical blood tests. The clinical stage of the oncological process was determined based on the results of a clinical examination. The possibility of using therapeutic manipulations was evaluated and the risks were assessed. To determine the clinical stage of the malignant process, such methods of visual diagnostics as magnetic resonance and computed tomography, rhinoscopy, chest X-ray, ultrasonography of abdominal organs were used. The degree of malignancy of oncopathology and the final diagnosis were made on the basis of morphological studies (histological and immunohistochemical studies).

Equestrian distance running is a relatively new sport for the North-West region, and conducting scientific research to identify fitness markers, as well as the best ways of training, preventing and treating injuries is an urgent problem. In this regard, horses are carefully examined at veterinary inspections before the competition, at each stage, as well as after the end of the competition. Veterinary commissions assess the quality of horse movements, metabolic indicators (degree of dehydration, peristalsis, capillary filling rate, muscle condition in the croup, back and girth), but pay special attention to the pulse. The cardiovascular health of an animal affects the performance and safety of horses and riders. Determination of the pulse is mandatory for equestrian distance races of any level and is regulated by the equestrian federation. The pulse was determined and the Ridgeway test was performed on horses participating in 2021 international equestrian distance races in the Netherlands at a distance of 120 km. Horses with a pulse rate within the reference range at the preliminary veterinary inspection demonstrated successful completion of the race. Therefore, the indicator of heart rate before exercise can be a predictor of the successful completion of distances in equestrian distance races. The Ridgeway test was not informative, as there were no statistically significant differences in the experimental and control groups. The Ridgeway Test is not intended to be performed at pre-competition veterinary inspections, however it is likely that the Ridgeway Test may be indicative of pre-load training, which is a plan for further research.

Synchronization schemes of sexual cyclicity are widely used in dairy cattle breeding to optimize reproductive function in cows and heifers. A comparative evaluation of the use of three synthetic analogues of gonadotropin-releasing hormones (GnRH) in a complex synchronization scheme was carried out, as well as the influence of the morphobiochemical composition of blood on fertilization was determined. For experimental work, 3 groups of full-aged cows were formed, 10 in each. The first group of animals was intramuscularly administered surfagon at a dose of 10 ml, the second – fertagil 2.5 ml, the third - fertagon 5 ml. In cows treated with surfagon fertilization after the first insemination was 70%, fertagil - 20%, fertagon - 50%. According to the results of 3 months of observations, after treatment with surfagon and fertagon, fertilization was 80%, with a multiplicity of inseminations of 1.13 and 1.38 times, respectively, whereas after treatment with fertagil, fertilization was 60% with a multiplicity of 1.67. The morphological picture of blood in infertile cows on the day of artificial insemination was characterized by a lower content of erythrocytes (by 10.7%; P<0.05), lower hematocrit (by 6.3%; P<0.05), with a higher content and concentration of hemoglobin in the erythrocyte (by 7.0%; P<0.05 and 2.9%; P<0.05, respectively). It was also found that infertile cows had lower progesterone levels on the day of insemination. Thus, in the group treated with surfagon, the hormone concentration was 2.7 times lower compared to those fertilized, in animals treated with fertagil 4.2 times (P<0.05), fertagon 2.0 times (P<0.05), which is apparently due to the different functional activity of the pituitary-gonadal system.

The article discusses the comparative morphological features of the skin of cattle of the Holstein-Frisian breed of the frontal region of the head, the gluteal region of the back, the umbilical region of the abdomen, the region of the pastern of the pelvic limb during puberty of the animal. The purpose of this study was to study the topographical features of localization of structural components of the skin of cattle of the HolsteinFrisian breed. The work was performed at the Department of Morphology, Physiology and Veterinary Pathology of the Agrarian Institute of the Ogarev Moscow State University. The object of the study was the skin of Holstein-Frisian cows bred in farms of the Republic of Mordovia. The study material was the skin of the frontal region of the head, the gluteal region of the back, the umbilical region of the abdomen, the pastern region of the pelvic limb. The processing of the material was carried out in the scientific laboratory of "Histophysiology" of the department. Pieces of skin for research were fixed in 10% neutral formalin. Histological preparations were made according to the standard procedure for light microscopy. Histological preparations were stained with hematoxylin and eosin, according to Van Gieson and Mallory. Morphometric studies were carried out using the Image J program. Statistical data processing was carried out using MS Excel 2007 and Statistica 6.0 application programs. The differences were considered significant at a significance level of less than 0.05 (p<0.05). The presence of pedigree morphological features of the skin of four areas of the body was established. They are characterized by differences in the thickness of the skin and its layers, the depth of the sebaceous, sweat glands and hair roots. The matrix of the papillary and mesh layers of the dermis has topographic features of the architectonics of the fibrous component.

Mineral elements are necessary components of the cells and tissues of the body. The imbalance of magnesium, potassium, phosphorus, calcium in the blood serum of animals affects the function of the cardiovascular system, contributes the development of myocardial dystrophy. Due to the intense functional activity, highly productive cows are more prone to the development of this pathology, therefore, the determination of their content of minerals during the prenatal period is relevant. To perform the study, two groups of highly productive cows of the Kostroma breed of the third or fourth lactation, which are in the prenatal period - 10-13 days before calving, were formed under the conditions of the livestock enterprise SPK "Gridino" of the Krasnoselsky district of the Kostroma region. The first experimental group was formed of 15 clinically healthy cows; the second experimental group included 5 cows with signs of myocardial dystrophy (tachycardia, weakness of heart sounds, specific ECG changes, etc.). The amount of important mineral elements for optimal myocardial function was determined in the blood serum, using the OLVEX reagent kits. The components such as magnesium and potassium, as well as total calcium and inorganic phosphorus were mathematically calculated on he basis of K:Mg and Ca:P ratio. It was found that in the blood serum of sick cows the level of magnesium was higher (1.85 times (P<0.001), against the lower values of potassium 29.57% (P<0.01), total calcium (by 10.9 %), inorganic phosphorus (by 10.8%) than in clinically healthy cows. This indicates a significant imbalance of the studied mineral metabolism components in highly productive cows in the prenatal period with myocardial dystrophy.

Post-injection abscesses, unfortunately, still occur in the practice of veterinary medicine, which indicates the unresolved problem of the use of medicinal solutions to accompany both surgical intervention and postoperative therapy. Depending on the presence, nature and severity of defects in injection needles, they cause various damage to biological tissues when they are punctured. In the article, the authors describe the influence of the surface microstructure of various injection needles on the nature of tissue repair at the injection site. Established microdefects in disposable injection needles for disposable syringes of different volumes (bending of its needle tips and much more) can increase the traumatism of animal tissues during injections. This implies higher requirements in the production of disposable injection needles, which should be minimally traumatic to biological tissues, as well as to quality control of their manufacture (checking for sharpness and the presence or absence of burrs when viewed with more than 2.5-fold magnification). The issue of possible clogging of tissues at the injection site with dust microparticles, which are formed when disposable syringes and injection needles are removed from sterile packages made of uncoated medical paper and transparent film, is also considered. Dust microparticles could most likely be formed in the process of damage to that part of the package, which is made of uncoated medical paper (paper is more structured than film).

The aim of the research was to study the effect of the type of higher nervous activity on the excretory function of the mammary gland. Cows are classified according to the types of higher nervous activity (HNA): First type - strong, balanced, mobile; Second type - strong unbalanced; Third type - strong inert; Fourth type – weak breaking. Under standard milking conditions, in cows of the first higher nervous activity type there were observed: a tendency or a significant increase in single milk yield and milking time in comparison with other types. The conditioned stimulus “foreign milkmaid”, when applied once or twice, caused an increase in the number of milk flow cycles in first and second higher nervous activity type cows with a decrease in the duration of one cycle both in the morning and lunchtime milking, compared with standard conditions. The following positively correlates with the intensity of milk flow: single milk yield, the milk flow rate for the first and second minutes of milking and maximum, the percentage of milk yield for the first and second minutes, the number of milk production cycles for two, three minutes and in general for milking. Negatively correlates the time of milk yield, the achievement of the maximum rate of milk flow and the total milking time. The process of inhibition of milk flow weakens these connections. The type of higher nervous activity in cows affects the relationship of indicators of milk flow both under conditions of varying degrees of readiness for milk flow, and action of conditioned and unconditioned stimuli on the animals used in the experiment.

Nonspecific resistance is a stable trait of a species. In farm animals, it’s defined by the breed and its pureness. The aim of the work is to determine the level of nonspecific resistance using integral hematological indices in breeding pigs of the Poltava Meat Breed under the influence of technological stress factors, depending on the genotype.
The main boars and sows of the Poltava Meat Breed, in accordance with the genotype, were divided into three groups according to the principle of analogous pairs: Group I – animals obtained “clean”, Group II – animals with the admixture of EarlyMaturing Meat Breed blood (in order to increase the adaptability), Group III – animals, with the admixture of the Finnish Landrace blood (in order to improve meat qualities). All animals belonged to the elite and first classes. To characterize nonspecific resistance, several integral hematological indices were used, such as: leukocyte index, immunoreactivity index, neutrophillymphocyte coefficient, Breddeck index, stress index, adaptation index, lymphocyte to monocyte ratio, neutrophil to monocyte ratio, allergization index. The results were processed statistically. It was found that boars and sows of the Poltava Meat Breed had significant differences in the level of the body's defenses, determined by the integral hematological indices. The research results showed that the genotype did not have a significant effect on the performance of certain indices in boars. In sows, a significant difference in genotypes was established only by the index of the neutrophil to monocyte ratio. In pigs of the Poltava Meat Breed under conditions of technological stress, specific features in the functioning of the nonspecific resistance mechanisms were found, most of them depending on the sex of the animals. The influence of the genotype on defense responses when exposed to technological stress was established only in sows. The obtained results are of great importance for the development of breeding measures and technological methods of animal keeping, which contribute to an increase in the functional capabilities of highly productive animals and obtaining high-quality products from them.

Due to the significant decline in the diversity of bird breeds and populations, there is a need to preserve germ cells of rare breeds and unique organisms, such as chimeras. The main method for preserving the gene pool in birds is the method of semen cryopreservation, which is used in many countries of the world in the form of creating cryobanks. Sperm from the birds of the breeds Brama light and Brama fawn and their chimeras were obtained by abdominal massage. Cryopreservation of the semen was carried out in small granules with the addition of a 6% solution of dimethylacetamide. The granules were thawed on a heated metal plate at 60°C. The ejaculate volume, sperm activity and its concentration in the studied breeds and their chimeras did not differ statistically. The maximum activity of the frozen-thawed semen was observed in the semen of the Brahma fawn breed (40.0%), and the minimum activity in the Brahma light breed was 30%, while in chimeras the semen activity occupied an intermediate position and amounted to 35%. Thus, frozen-thawed spermatozoa of bird chimeras are viable, as well as native semen.

The article presents the results of an experimental evaluation of the effectiveness of the estrus synchronization program under ultrasound control for diagnosing the state of the ovaries in cows. In this work, the influence of hormonal preparations on the dynamics of lysis of the corpus luteum and the growth of follicles in the ovaries in cows with the help of an ultrasound machine is determined. Evaluation of the effectiveness of synchronization of estrus and determination of the effect of hormonal preparations on the state of the ovaries in dairy cows was carried out from March to August 2021 in the Volgograd region on the farm of Donskoye JV LLC. To conduct a production experiment, two experimental groups of Holstein cows were formed, 30 heads each.
For ultrasound examination of the ovaries in the second experimental group, an Easi-Scan Curve ultrasound scanner from BCF Technology was used. Linear matrix converters with a frequency range from 5.0 to 7.5 MHz. Transrectal ultrasound was performed by introducing an ultrasound transducer into the rectum. This made it possible to visualize and evaluate the architecture of the ovaries.
As a result, the analysis of the ultrasound image revealed that the double use of Prosolvin contributes to the regression of the corpus luteum. Before the use of prostaglandin, the corpus luteum had a size of 3x2 cm, but after the intramuscular injection of Prosolvin, the corpus luteum regressed, its size began to decrease, then it completely disappeared. After the use of Ganodin, the level of luteinizing hormone in the blood of animals begins to increase, which contributes to folliculogenesis, ovulation of follicles and the manifestation of estrus.
Thus, ultrasound diagnostics of the ovaries made it possible to reduce the cost of hormonal preparations and timely put the animals on treatment.

The article presents the results of a study of the influence of negative energy balance in cows in the transition period in the development of postpartum uterine pathologies. On the sonogram, metritis is presented as a hypoechoic uniform thickening of the layers of the uterine wall. With pyometra, thinning of the uterine wall occurs. On the sonograms obtained during the study, cavities of considerable diameter (average 67.8 ± 4.6 mm) with hypoechoic content, with the presence of hyperechoic inhomogeneous inclusions of varying echo intensity, are visualized. During the histological examination of the obtained biopsy, it was determined that the proportion of the integumentary epithelium in cows with pyometra and metritis is higher than in clinically healthy animals. Changes were also noted regarding the proportion of the uterine glands in assessing the overall structure of the endo metrium. With metritis, this indicator was 5.22 ± 0.03%, and with pyometra 4.07 ± 0.01%, which is more than 7 times lower than when assessing the same indicator in co ws without clinical signs of metritis and pyometra . A change in these indicators indicates the development of degenerative - dystrophic processes in the uterus, including the uterine glands, which occur in combination with catarrhal -purulent lesions of the uterus. As a result of blood tests, we found that purulent-catarrhal inflammation of the uterus in newborn cows occurs against the background of oxidative stress. It was found that the concentration of catalase in the blood of cows with metritis and pyometra was increased by 43.0% (p<0.05). Also, sick cows showed a significant increase in the content of malondialdehyde (p<0.05). In contrast to the data obtained from clinically healthy cows in patients with catarrhal-purulent lesions of the uterus, a decrease in the content of vitamin C was noted – by 30.9% (p<0.05) and vitamin E – by 2.02 times (p<0.01) . Also, in sick cows, a number of changes were revealed in the biochemical study of blood serum, indicating the presence of a violation of various types of metabolism, in particular dysproteinemia, hypercholesterolemia and an increase in enzyme activity.

Increasing the reproductive qualities of animals is the main task of dairy farms. Replacement of the main breeding stock with young animals, often leads to the fact that young animals, being exposed to ovarian diseases, undergo a longer recovery time and reduce the effectiveness of artificial insemination. This work highlights the issue of infertility of cows in specific farms, under certain feeding and housing conditions. The aim of the work was to develop a system therapy of infertility of cows with ovarian diseases.
The experiment was conducted in two farms of Uvinsky district of the Udmurt Republic, with the formation of six groups of animals in each farm for each individual disease. In particular, the main diseases were ovarian hypofunction and ovarian follicular cysts. Six schemes of ovarian therapy were developed.
During a gynecological examination, hypofunction of the ovaries was found in 14% of cows in the SPK "collective farm Udarnik" and in 18% of cows in OOO "Riko-Agro". Follicular ovarian cysts were found in 10% of cows in the SPK "collective farm Udarnik" and in 12% of cows in LLC "RikoAgro". During the experiment, the activity of the manifestation of sexual characteristics in cows was monitored. At the same time, it was found that with hypofunction of the ovaries, all experimental cows came into heat only according to scheme No. 2. This scheme includes drugs such as Surfagon and ASD-2fr emulsion. and Tetravit. In the treatment of follicular ovarian cysts, attention was paid to the regression of cysts. The greatest amount of cyst regression (100%) was achieved using scheme No. 5, which includes Metrostim, Fertagon and Estrofan.
As a result of the work, we found that in the case of ovarian hypofunction, the most effective treatment regimen included Surfagon, ASD-2fr. and Tetravit. The rate of cow fecundation was over 67% of cows in both farms on the first insemination. With follicular ovarian cysts the greatest efficiency of therapy was achieved using the scheme including Metrostim, Fertagon and Estrofan.
Fertilization of cows at the first insemination after therapy was also more than 80%. For the purpose therapy of these diseases, we recommend to use schemes including the above mentioned drugs.

Musculoskeletal system diseases are in the first place in the structure of dogs’ admission to veterinary clinics. Lameness in dogs are diagnosed in about 70% of the cases in the hind limb, whereof about 50% are attributed to the knee joint. One of the most frequently diagnosed pathologies of the knee joint is the patella luxation (PL). The aim of our study is to determine a relation between the development of comorbid pathologies of the knee joint (such as patella luxation, cranial cruciate ligament disease, osteoarthritis) with the degree of dislocation, age, general condition of the animal, changes in hematological and biochemical parameters of blood, and based on this to justify the need for PL surgical treatment at an earlier age. The study was conducted at the facilities of St. Petersburg State University of Veterinary Medicine and VEGA veterinary clinic chain in the city of St. Petersburg, Russia. The study was carried out on 48 dogs with different breeds, gender and age, with varying PL grade, which had not previously undergone knee joint surgical treatment. The animals were allocated into two groups depending on the knee joint concurrent pathologies: 20 dogs with PL only — in group 1, 28 dogs with knee joint polypathologies (PL, cranial cruciate ligament disease, and osteoarthritis) — in group 2. According to the results of statistical analysis using the Mann-Whitney U-test, the average age (3.4 years and 6.9 years, respectively) and the degree of lameness (2.0 and 3.0, respectively) are statistically significantly different in dogs of the 1st and 2nd groups. There are also statistically significant differences in the levels of segmented neutrophils (5.8 and 9.6×10^3/mkl in dogs of the 1st and 2nd groups, respectively) and lymphocytes (7.2 and 9.6×10^3/ mkl, respectively). A statistically significant increase of the serum concentration of bilirubin, ALT, alkaline phosphatase, GGT and triglycerides was detected.
The obtained results allow to recommend surgical treatment of PL at an earlier age, since in the absence of timely treatment, comorbid knee joint arthropathies, such as PL, cranial cruciate ligament disease, osteoarthritis, develop, which requires more serious surgical interventions against the background of a more severe general condition of animals.

The article presents the results of the dynamics of indicators of protein, nitrogen and carbohydrate metabolism during castration of boars in industrial production against the background of immunocorrection with thymogen. The studies were carried out on 14 boars (aged 5 months), selected by random sampling from 38 animals in compliance with the principle of paired analogues and divided into two groups ‒ control and experimental ones (n=7 in each). All boars were castrated by an open method with preoperative medical support according to the methodology adopted in the farm. Animals of the experimental group were additionally injected with thymogen for a five-day course. During the experiment, the content of C-reactive and total proteins, albumin, globulin, urea, creatinine, glucose was determined in the blood serum. Albumin-globulin ratio was determined by the calculation method. According to the results of the experiment, it was found that castration of boars was accompanied in both groups at all stages of the experiment by an increase in the content of C-reactive protein, changes in protein metabolism, mainly in the catabolic phase of the postoperative period ‒ a decrease in the concentration of total protein, globulin below the norm in the control group with similar dynamics of indicators in the experimental group, but within the reference intervals. Further dynamics were positive in the direction of normalization at the anabolic phase. The dynamics of urea and creatinine in both groups had a wave-like character, not going beyond the normative values, the level of urea increased with a subsequent decrease, creatinine – vice versa. Their final levels were lower than the original ones.
The use of thymogen largely leveled the intensity of changes in the catabolic phase of the pathological process and contributed to the normalization of the biochemical profile at the final stage of the experiment.

The article presents data on the effect of castration on changes in indicators reflecting mineral metabolism. The work was performed on 14 boars (aged 5 months) divided into two groups ‒ control and experimental ones (n = 7 in each). Before castration by an open method, all animals were intramuscularly injected with ketoject; and in the postoperative period, medical support consisted of repeated use of the abovementioned drug, as well as cobactan and hipratopic. The boars of the experimental group were additionally injected with thymogen.
Blood sampling was performed before the surgery, on the 14th and 30th day after it, the serum was obtained using the conventional method. The content of calcium, phosphorus, sodium, potassium, chlorine, magnesium was evaluated.
It was found that the indicators of sodium, potassium, chlorine and magnesium before castration of boars were within the physiological norm in both groups, while the indicators of both calcium and phosphorus exceeded physiological norm in the control and experimental groups by 1.46 ‒ 1.51 and 1.14 ‒ 1.22 times, respectively.
Further dynamics of calcium and phosphorus was accompanied (in the catabolic phase) by hypocalcemia, a decrease in the level of phosphorus to reference values, in the anabolic phase by normalization of the calcium content against the background of a slight excess increase in phosphorus.
The use of thymogen in the experimental group contributed to a decrease in the intensity of changes on the 14th day and normalization of calcium and phosphorus on the 30th day. There were no significant fluctuations in the dynamics of sodium and chlorine. Potassium levels in both groups in the catabolic phase exceeded both the initial and standard values (mostly in the control), in the anabolic phase this trend persisted in relation to the control against the background of normalization in the experimental group. The content of magnesium in the blood serum of boars was characterized by positive dynamics: indicators were below the norm before castration, the reference values were subsequently noted in the control group on the 14th day, in the experimental group ‒ on the 30th. The presented research results indicate that the protective effect of thymogen in optimizing mineral metabolism during castration of boars is mainly realized at the level of calcium and phosphorus dynamics.

The main task in livestock complexes is to ensure the safety of livestock and to obtain healthy young animals. It is known that in the last months of pregnancy in cows, the fetal weight increases by 70-75 %, all the organs of the immune defense and the enzymatic system develop, and, consequently, the general resistance of the newborn young is formed. This underlines the importance of creating optimal conditions for feeding and keeping pregnant animals. Therefore, when developing rational measures for the prevention and control of diseases of nascent young animals, it is necessary to consider this complex as a single system, since the physiological immaturity of newborns cannot be further compensated even by ideal growing conditions.
The use of a composition based on a mycelial fungus and an organosulfur compound is a promising preventive agent that does not have a pronounced negative effect on the animal's body. The proposed therapeutic two -component composition for pregnant cows consists of selimaccide and a commercial preparation «Milife» containing a culture of the mycelial fungus Fusarium sambucinum strain VKPM F-139. Selimaccide is the diethylammonium salt of N-methylamino-1-phenylmethanesulfonic acid, belongs to the new chemical compounds of the class of aminomethanesulfonates, is a white crystalline powder with a specific odor, well soluble in water, alcohol, dimethylsulfoxide.
Daily watering of the proposed composition to pregnant cows 12 days before calving 2 times a day at a dose of 500 cm3 / head with an interval of 6 to 8 hours ensures the birth of calves resistant to gastrointestinal disorders.
The aim of the research was to study the effectiveness of the drug, which is a combination of selimaccide and the mycelial fungus Fusarium sambucinum strain VKPM F-139 as a means of preventing gastrointestinal disorders in newborn calves when applied to pregnant cows.

Any surgical intervention is a surgical trauma, which severity depends on the type and degree of surgical intervention. Several changes occur in the patient's body in response to surgical trauma, which degree depends on the functional state of systems and organs in the preoperative period. In our study, we investigated how chronic heart failure (CHF) affects the development of such a factor of surgical trauma as hypoxia. The aim of our study is to determine whether CHF is a risk factor for the development of intraoperative hypoxia in animals during surgical interventions lasting up to 60 minutes. Lactate level was chosen as a marker of hypoxia. The study was conducted at the facilities of St. Petersburg State University of Veterinary Medicine and VEGA veterinary clinic chain in the city of St. Petersburg, Russia. The study was carried out on 20 dogs with myxomatous mitral valve disease (MMVD). The animals were allocated into three groups depending on the stage of the disease: seven dogs with MMVD in stage B1 — in group 1, eight dogs with MMVD in stage B2 — in group 2, five dogs with MMVD in stage C — in group 3. The lactate level in whole venous blood was measured in all animals before the operation (at rest and under load), during the operation and two hours after the operation. The mean lactate increase under load in group 2 dogs was 0.08 mmol/L, and in group 3 dogs — 0.20 mmol/L. According to the results of statistical analysis, the increase in lactate under load in dogs with MMVD in stage C statistically significantly exceeds the increase in the level of lactate under load in animals with MMVD in stage B2. Thus, MMVD in stage C can be considered a risk factor for the development of intraoperative hypoxia.

The purpose of the article is to reveal the regional experience of the transition to a new model of agricultural education. The article notes the need for a transition to a new model of agricultural education, which is based on practice-oriented and competence-based approaches. The authors have identified the main areas of activity of the university associated with the implementation of the designated model: structural and managerial, educational, educational and industrial, behavioral. In conclusion, it was concluded that, despite all the difficulties, regional agricultural education is being adapted to meet market demands - new programs are being developed and implemented, digital solutions and new teaching methods are being introduced, agricultural business is involved in the implementation of the educational process.