To date, the swine reproductive and respiratory syndrome virus (RRSS) has been registered in most countries of the world, including Russia. This disease remains one of the important problems in pig breeding, as it causes huge losses to this industry.

The authors conducted a study where epizootological data and clinical signs of the incidence of RRSS in the conditions of the breeding farm "Zadneprovsky" and materials for evaluating the effectiveness of RRSS vaccine prevention with an analysis of economic indicators. The diagnosis of RRSS was made on the basis of clinical, pathoanatomic and serological research methods. By the number of antibodies in the blood serum of animals, the intensity of immunity to the RRSS virus was judged. Virus-specific antibodies were determined by enzyme immunoassay (ELISA).

It is established that if the virus appears in the herd for the first time, all sows with impaired reproductive function, accompanied by 100% abortions, premature birth, become ill. Among the piglets born from sick sows, there are a large number of stillbirths, and among the surviving piglets, there is a high mortality rate, stunting and unsuitability for cultivation. It is noted that the number of stillborn piglets is always higher in the first moments of the onset of the disease than with repeated farrowing.

After getting over the disease, the bulk of sows quickly recover and, with repeated farrowing, bring viable piglets. Immunization of piglets against the background of a decrease in maternal immunity with a live vaccine against RRSS is accompanied by the formation of a tense immunity that protects them from the disease.

Currently, in many pig farms, vaccination of pigs against RRSS is included in the mandatory program of preventive vaccinations against infectious diseases.

A method for diagnosing infectious synovitis among young broilers aged 11-12 weeks, obtained from an industrial-type poultry farm, was investigated in laboratory conditions. The experiments were carried out on the basis of the Microbiology Department of the All-Russian Research Veterinary Institute of Poultry Farming - a branch of the VNITIP Federal Research Center of the Russian Academy of Sciences. To perform mycoplasmatological studies, the limbs of birds with pronounced joint damage were selected and a nutrient medium was prepared by adding 20% horse blood serum, 10% yeast extract and 0.5% glucose to Edward's broth. Phenol-mouth at a concentration of 0.0001% was used as an indicator of the medium. As a result of a series of 7 "blind" passages, the appearance of opalescence and precipitation was noted, small transparent colonies were observed on a dense nutrient medium. Thus, the preliminary diagnosis of infectious synovitis (infektious synovitis) of broilers, obtained on the basis of epizootological data, clinical signs and pathoanatomic changes, was fully confirmed by a positive result of mycoplasmatological studies. According to the results, tilan was proposed for the treatment of sick poultry in doses recommended by the manufacturer, and for the prevention of the disease – strict compliance with the norms of bird planting density and indoor microclimate.

To prevent bacterial infections in birds, poultry farms often use feed antibiotics. Based on this, residues are often registered in products from such birds, which is dangerous for humans. Dietary supplements help to safely replace antibiotics and produce environmentally friendly products. They have a positive effect on the body of poultry: improve intestinal and microbial balance and, consequently, increase their safety and productivity.

The aim of the work was to study the ability of "Probiocid® Ultra" to inhibit the development of Clostridium perfringens. In the conditions of vivariums on the basis of SRCC of poultry farming experiment with chickens-broilers of cross "Ross-308" was put. Daily chickens were divided into 3 groups of 40 chickens at random - 2 control groups and the group, in the diet of which was introduced a complex of additional food "Probiocid® Ultra".

The birds were kept in the vivarium for 38 days. The microclimate, lighting, feeding and watering front complied with the requirements of Ross-308 cross. Since the age of 15 days 1 control group and the group with complex of additional feeding were infected with Clostridum perfringens at the dose of 1 billion microbial bodies per head. As a result of the experiment it was found that the studied Probiocid-Ultra has a positive effect on the poultry organism. When introducing this complex of supplementary nutrition in the diet of broilers under condi tions of Clostridium perfringens infection, a significantly higher preservation of livestock compared with the infected control was observed. Thus, it can be concluded that the use of the complex "Probiocid® Ultra" is able to protect poultry under conditions of high pathogenic load on the body.

Mastitis in cows is currently a pathology that causes great economic damage to livestock farms around the world. The quantitative and qualitative indicators of milk are decreasing. Prevention and treatment of breast inflammation in cows is one of the main tasks of veterinarians. For successful treatment, it is necessary to understand the etiology, especially in infectious mastitis. The degree of inflammatory reaction depends on the invading pathogen and the state of the animal's body, including such indicators as the stage of lactation, age, immune status, genetics and feeding diet. Almost 200 microorganisms that cause bovine mastitis have been identified, including bacteria, yeast, fungi and viruses. More than 150 species of bacteria that cause mastitis in cows have been identified, with bacterial mastitis being the most common. Mastitis can be caused by gram-positive bacteria, the most common of which are staphylococci and streptococci, and gram-negative bacteria, more often Escherichia coli and Klebsiella pneumoniae. Laboratory diagnostics is necessary to isolate and identify the relevant pathogen, which is necessary for the successful prevention and treatment of mastitis. The most commonly used method of diagnosing mastitis in cows is to measure the number of somatic cells. Express diagnostics are often used, which do not give a numerical result, but indicate only low or high indicators, while the causative agent of mastitis is not identified. The cultivation method is still the main criterion for detecting microorganisms, but it is a very time-consuming and expensive method. With the development of molecular methods, rapid and accurate diagnosis of diseases in animals has become possible. Recently developed diagnostic tests have shown high specificity and sensitivity.

There is a serious problem in the production of poultry meat - the potential probability of its exogenous seeding by pathogenic microorganisms - causative agents of food infections, toxicoinfections and toxicosis. These are Escherichia, Salmonella, Staphylococcus, Campylobacter and other bacteria. Disinfection in cooling baths should ensure the destruction of such microorganisms on the surface of carcasses and prevent the threat of contamination of consumers of poultry products. Purpose of the work: to determine the effectiveness of the use of the disinfectant "DEZON NUK 15" in cooling baths for surface treatment of chicken and turkey carcasses after slaughter and evisceration. To study the bactericidal action of the prepared solutions, we used models - poultry products of broilers and turkeys (chilled wings) with good organoleptic characteristics. The models were contaminated with cultures of sanitary indicative and pathogenic bacteria: Staphylococcus aureus, Escherichia coli, Salmonella Enteritidis, Campylobacter jejuni, Bacillus subtilis. Contaminated models were kept in working solutions of a disinfectant with a concentration of 0.025%, 0.050%, and 0.100% according to NUK. After an exposure of 10, 25 and 40 minutes, inoculations were made on nutrient media from the surface of the models and incubated under optimal conditions. Found that the drug "DEZON NUK-15" has bactericidal activity against the tested working cultures of bacteria. After contamination with the tested cultures of bacteria, the surface of poultry products of chickens and turkeys is disinfected with a solution of the drug "DEZON NUK-15" with a concentration of 0.050% and 0.100% for 25-40 minutes. No changes or deterioration in the organoleptic characteristics of poultry products was observed. The bactericidal effect of the drug is practically the same in relation to poultry products of chickens and turkeys.

Nowdays, viral plasmocytosis of mink is widespread all over the world, due to the lack of effective treatments. A key role in the outcome of the disease is often played by kidney damage associated with the development of glomerulonephritis as a result of hypergammaglobulinemia. It is for this reason that the problem of finding a remedy for the treatment and prevention of Aleutian mink disease becomes urgent. The studies were carried out on mink of the sapphire breed at the age of 30 to 40 days in patients with viral plasmocytosis, confirmed by molecular genetic analysis. The experimental and control groups consisted of 20 animals each. The minks of the experimental group were injected subcutaneously twice with an interval of 6 days with alloferon at a dose of 0.5 mg per head, and the minks of the control group were injected with saline solution (NaCl 0.9%) in the same volume and multiplicity. During the study, records of fallen minks were kept. At the end of the experiment, histological studies of internal organs were carried out. The conducted experience showed that the use of alloferon led to a reduction in mortality, as well as a several-fold decrease in the intensity of plasmocytic infiltration of organs and tissues in experimental minks.

The drug "Protostop" containing 100.0 mg of paromomycin sulfate in 1.0 g was used in calves with cryptosporidiosis.The animals in the experimental groups were given the drug at a dose of 250 and 350 mg per 1 kg of animal weight individually, orally, in courses of 3 and 5 days, respectively. Before use, a single dose of the drug was dissolved in water by adding liquid to the powder. The calves of the control group received symptomatic treatment aimed at eliminating the diarrheal syndrome. Before the start of the therapeutic course and on the 10th day after its completion, blood was taken from the animals of the experimental and control groups for general clinical analysis.The physiological state of the animals was recorded before the administration of the drug and on the 4th, 6th, 8th, 12th and 15th day from the start of treatment. It was found that the treatment of calves with cryptosporidiosis with the drug "Protostop" at a dose of 250 mg/kg and 350 mg/kg in 3 and 5 -day courses did not cause negative changes in the animals' bodies. Before the start of the treatment, the hemoglobin content of the calves in all groups were lower than the reference values. Thrombocytopenia, eosinophilia and neutrophilia were also recorded and an increase in ESR was noted. After using the drug, the indices of eosinophils, segmented neutrophils and ESR were within the reference values, the hemoglobin level slightly increased. After using the drug, the indicators for eosinophils, segmented neutrophils and ESR were within the reference values, while the hemoglobin levels were slightly increased. Calves in the control group, despite symptomatic treatment, eosinophilia were observed with an increase in the percentage of segmented neutrophils and ESR. During the course of treatment, as well as 10 days after its completion, the calves showed no deterioration in their physiological state, hyperemia of the mucous membranes, itching or other signs indicating a possible side effect to the drug.

One of the most pathogenic helminth species for the young of the northern fur seal (Callorchinus ursinus) is the nematode (Ancylostomatidae family) Uncinaria lucasi. The ecology of the definitive host determines the adaptation of the parasite to the host, the development of additional transmission mechanisms. The main adaptation of the parasite to the host is the ability of invasive larvae to settle in the tissues of all sex and age groups of the seal herd, which makes it possible to avoid wintering in the ground. At present, the fate of these larvae is unknown, as well as the role of each of the age groups of seals in the implementation of the life cycle of this helminthiasis, in connection with which the purpose of the work was to determine the role of the sex and age groups of the seal herd to maintain the hostparasitic system of the seal – uncinaria. The study found that female northern fur seals are a mandatory link in the life cycle of U. lucasi and they should be considered as.

Dyspeptic symptoms are common in neonatal calves from BLV-infected cows. A single drinking of the made by authors composition (patent No 2646831) prevents dyspepsia in animals. The article is devoted to the analysis of representative indicators of intestinal microbiota of the calves from infected with leukemia cows, under dyspeptic manifestations prevention. It was shown that by the 14th day after drinking the composition, the number of intestinal Lactobacillus in calves increased and was 2 times higher than in animals without drinking the composition. The quantity of Bifidobacterium in newborn calves of the control group at first sharply decreased, and then gradually restored. In the experimental group calves, the dynamics of Bifidobacterium was positive. Conditionally pathogenic Enterococcus and Escherichia coli were presented in the control group of calves in an order greater than in animals of the experimental group, and Staphylococcus - almost 2 times higher. The Proteus and yeast-like fungi content normalization in the both groups calves occurred rather quickly under the influence of normal intestinal microflora. Thus, use of the original composition for dyspeptic manifestations prevention in neonatal calves from immunocompromised cows, promotes the rapid colonization of the calves intestines with normal microflora.

Hematological leukocyte indices provide additional information about intoxication and the state of the immune response and become an alternative to determine a number of immuno-biochemical parameters. The aim of the work is to study the effect of the antioxidant mitophen on the leukocyte indices of blood that characterize the nonspecific reactivity of the organism of broiler chickens. The chickens of the I and III experimental groups were given mitophen daily from the daily age at the rate of 25 and 50 g/t of feed for a month, the II and IV-25 and 50 g/t of feed only in the first and third weeks of the experiment. The control group received the main diet without the drug. The leukocyte indices were determined mathematically by the leukogram. It was found that the use of mitophen significantly increases the index: of shift of blood leukocytes, of the ratio of eosinophils and lymphocytes, and lowers the index of the ratio of lymphocytes and eosinophils, which indicates the positive effect of the drug on the granulocytopoiesis and nonspecific resistance of broiler chickens. At the same time, the use of mitophen significantly reduces index: of immunoreactivity, of the ratio of lymphocytes to monocytes, and pseudoeosinophils to monocytes, which characterizes the positive effect of the antioxidant on monocytopoiesis and nonspecific cellular immunity of the bird body due to monocytes.

Now in animal husbandry, more than 70 types of antibiotics are used, belonging to various groups. The most popular are longknown groups: penicillins, tetracyclines, fluoroquinolones, cephalosporins. The main reasons for the use of antibacterial agents are the presence of visible and latent pathologies in cows. Milk contaminated with antibiotics not only has significant restrictions on its use in processing, but also poses a serious threat to humans, as the end consumer of dairy products, as it provokes the development of antibiotic resistance. Laboratory studies were carried out on the basis of the Tyumen Regional Veterinary Laboratory in the Department of Microbiology, during 2019- 2020, the object of the study was 407 milk samples obtained from cows kept both in private farmsteads and in agricultural enterprises. It was found that 55.83% of raw milk samples delivered to the laboratory were contaminated with antibiotics. The most common antibiotic found in raw milk is amoxicillin (40.47% of all samples containing antibiotics), doxycycline (21.86%) was subdominant, erythromycin and azithromycin were encountered to a lesser extent (11.16% each), levofloxacin was encountered in 8.84% of milk samples with antibiotics, in rare cases the presence of streptomycin was recorded (6.51%). Most often, antibiotics were found in the summer. Thus, 54.42% of samples containing antibiotics were detected from June to August. Spring time accounted for 22.33% of all samples containing antibiotics. In autumn and winter, the proportion of samples with antibiotics was the smallest and amounted to 16.74 and 6.05%, respectively.

In terms of natural and climatic conditions, the Stavropol Territory is favorable for the development of a number of ectoparasites on animals, which cause significant damage to the development of productive animal husbandry. One of the most common diseases in sheep breeding in the south of Russia is wohlfahrtiosis. This disease is caused by parasitizing of the Wohlfahrtia magnifica larvae, which can lay larvae on the scratches and wounds of the animal. In June 2021, a production experiment was conducted in Filimonovskaya stanitsa, Stavropol Territory, to test a drug Delcid® 7.5 for veterinary use during wohlfahrtiosis in sheep. All experimental animals (30 sheep) had skin damage after shearing and were invaded by W. magnifica. Three groups of 10 sheep each were formed. All sheep of the experimental group No. 1 with skin damage had one-time treatment with Delcid® 7.5 by applying it to the skin of the back, from the head to tail base along the spine, at a dose of 10 ml per animal. It was determined that the insecticidal effect occurred after 3 days, and the duration of the protective effect of the drug Delcid® 7.5 (serial number 040421O) against the W. magnifica, in which the COP was higher than 70%, lasted 35 days. The treatment of sheep from experimental group No. 2 was carried out by local application of the drug Delcid® 7.5 to the affected by W. magnifica larvae areas of the animal body with a cotton pad with an application rate of 0.2 ml/cm2. It was determined that the death of W. magnifica larvae occurred 60 minutes after the drug was used. The sheep of the control group No. 3 were infested during the entire experiment – 42 days.

The article presents information on the prevalence of subclinical endometritis in cows, which were carried out on the basis of ZAO breeding farm "Povadino", as well as morphological changes in the mucous membrane of the uterus in this pathology. On the basis of the diagnosis, the animals were treated using various schemes with antibacterial drugs based on cefapirin. The studies were carried out on the basis of the Department of Anatomy and Histology of Animals named after Professor A.F. Klimov FGBOU VO MGAVMiB - MBA named after K.I. Scriabin, as well as at ZAO Povadino breeding plant, cytomorphological studies were carried out on the basis of the Chance Bio laboratory in the period from 2019-2021. According to the principle of analogs, 3 groups of animals with the manifestation of subclinical endometritis (15 animals in each) were formed. The animals of the first (experimental) group were injected with the drug "Mitrek"; the animals of the second (comparative) group - the drug "Metrikur", the animals of the third (control) group were injected with the drug "Tylosinocar" intrauterinely, according to the instructions. A comprehensive methodological approach was used, including clinical examination of animals, fine anatomical preparation, cytomorphological examination of cervical mucus, statistical analysis of the obtained digital data, light microscopy of histological sections stained by the classical technique with hematoxylin and eosin. To determine the extent and etiology of postpartum endometritis in black-and-white Holsteinized cows, obstetric-gynecological clinical examination was carried out, which was carried out according to the generally accepted method. In addition to general clinical methods for diagnosing this pathology, cytomorphological studies of 120 smears of cervical mucus were carried out to objectify the diagnosis. Based on the results of a comprehensive study aimed at identifying subclinical endometritis, it was found that this pathology is observed in 53.55% of the studied animals, macro- and morphological changes in the uterus with subclinical endometritis were revealed. endometrium, due to the influence of pathogenic microflora: Staphilococcus aureus, Escherichia coli, Streptococcus viridans group. And also, based on the results of the studies performed, a comparative assessment of the therapeutic efficacy of drugs based on cefapirin was carried out.

The influence of early immunological stimulation on the dynamics of the morphobiochemical composition of blood and the increase in live weight in calves of the black-and-white Holstein breed was evaluated. For the experiment, 3 groups of young animals were formed at the age of 7 days, 10 calves in each. The first group of animals was injected with 500 UNITS of bovine recombinant interferon-a2b, the second group used denatured emulsified placenta (PDE) of 5 ml, the third group of calves served as a control, where saline solution was used. The treatments were performed twice with an interval of 7 days. Blood collection was carried out before injections, on 7 and 14 days after the start of the experiment. After a single admin istration of interferon, an increase in urea level was observed by 44.7% (P< 0.05), while the indicator was higher by 13.6...37.5% (P < 0.01) in relation to the group of calves treated with PDE. The activity of transaminases in the experimental groups did not have significant dynamics, when in control calves AST increased by 28.9% (P≤0.05), and ALT by 2.3...2.7 times (P≤0.05...0.01). The activity of alkaline phosphatase in calves treated with PDE and saline solution was stable, in the first group the indicator decreased by 16.2...17.6% (P≤0.05...0.01), which is less by 21.8% (P≤0.05) in relation to the group of calves treated with PDE and by 45.5% (P≤0.05) in relation to the control. In the first group of calves, there was a decrease in total (by 46.7%, P < 0.05) and free bilirubin (by 37.2%, P < 0.01). The total bilirubin decreased by 47.5% (P < 0.01) in the young animals injected with PDE, while the indicator increased slightly in the control group. Under the influence of interferon, BASC increased by 30.9% (P < 0.05) after the first injection and by 43.2% (P < 0.05) after the second injection. Double administration of PDE contributed to an increase in BASC by 42.0% (P≤0.05). LASC in the first group increased by 47.1% (P≤0.05), which is higher than the control animals by 19.0...38.9% (P≤0.05). In the third group, there was also an increase in WEASELS at the time of the last blood collection (by 40.0%, P<0.05), while in calves that were injected with PDE, the increase in the indicator was not significant. The increase in live weight in the first three months of life during the use of interferon was greater by 7.3 kg or 12.7% (P >< 0.05) compared to the control group and by 3.2 kg or 5.1% compared to the group treated with PDE.

To date, there are many ways to detect the falsification of caviar. These include organoleptic and laboratory research methods. However, when adding counterfeit in the amount of up to 25% of the total weight of the product, it is quite difficult to establish the fact of falsification. That is why in veterinary and sanitary practice, polymerase chain reaction is increasingly resorted to. The purpose of the research was to identify the species of salmon fish eggs using polymerase chain reaction with real-time observation (PCR-RV). Identification was carried out in two stages. At the first stage, the eggs were homogenized with subsequent DNA extraction by the adsorption method using a set of "Sorb-GMO-A" (Syntol, Russia). At the second stage, PCR-RV was performed on the Rotor-Gene Q amplifier (Qiagen, Germany) using the Pink Salmon/Chum Salmon/ Sockeye Salmon (Syntol, Russia) and Salmon/Trout test systems/Kizuch" (Organic Test, Russia). The results were evaluated by the kinetic growth curve of the fluorescence signal depending on the DNA present in the studied caviar and the threshold cycle value Ct ≤. 35.

The existing organoleptic and physicochemical methods of veterinary and sanitary examination of caviar make it possible to determine its quality and safety. It is extremely difficult to determine the species of caviar using these methods. Polymerase chain reaction is the most sensitive method for identifying the species of caviar and revealing the facts of its falsification.

In this study, the influence of various cryoprotectants on the viability of the consortium of probiotic microorganisms Lactobacillus plantarum 8 β and Bifidobacterium adolescentis 17-11 β 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 72 oC, the lyophilization process lasted 26 hours, during which the vacuum index varied from 40 Pa to 4 Pa, The temperature was raised to 28 оC. 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 37 C 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.

Obesity of chickens significantly reduces the efficiency of feeding, egg production, palatability of meat carcasses, slaughter yield, consumer value, and there is also such an ecological aspect as the problem of fat utilization. The search for SNPs in genes involved in lipid metabolism is an important task today for modern research in the field of poultry farming. Differences in carcass fat between breeds and lines within a breed illustrate the importance of genetic factors in lipid metabolism in chickens. The aim of the study was to find and analyze SNPs in the PPARG gene by sequencing in various chicken breeds (n = 83). The objects of the study were chickens from the VNIIGZh bioresource collection "Genetic collection of rare and endangered chicken breeds" (Pushkin, St. Petersburg) of various productivity trends (n = 83). Blood for DNA isolation was taken from hens at the age of 330 days from a wing vein into a microtube containing 50 μl of 0.5 mM EDTA as an anticoagulant. Prior to use, blood samples were stored at -200C. Genomic DNA was isolated using a standard phenolic-detergent method. The concentration and purity of the samples were determined using a NanoDrop 2000 instrument (Thermo Fisher, USA).

Analysis of the polymorphism of the regulatory region of the PPARG gene was carried out by sequencing. The primer design was carried out on the basis of information from the Internet database.The studies were carried out on the basis of the laboratory of molecular genetics of the RRIFAGB. Genetic variability for rs314476701 of the PPARG gene was determined in the analyzed breeds. SNP rs316237745 revealed a strong shift of the A.

The article deals with the issue of the ecological and toxicological state of the Volkhov Bay of Ladoga Lake — one of the most polluted water areas of the reservoir, which is of important fisheries importance and has a significant impact on the water quality of the Neva River in winter. Biological and chemical-analytical studies conducted in the summer of this year showed mass lesions of fish with chronic toxicosis. The study of water and bottom sediments did not reveal pronounced deposits from the norm, which is associated with the hydrological features of this water area — the nature of bottom sediments and the presence of currents, which contributes to the removal of pollutants outside the lip into the lake. Fish turned out to be the most informative indicators of the quality of their habitat. The study of various fish species caught in these waters showed that their toxicosis, regardless of the type, is of a massive nature, proceeds chronically, mainly with mild and moderate injuries in the gill tissue and parenchymal organs. It is shown that the lesion of fish is associated with and more pronounced in the water areas gravitating to the sources of pollution — the mouth of the river Volkhov and the stock of the Syasky Central Bank. Assessing the ecological and toxicological state of the Volkhov Bay at the present time in comparison with the results of past studies, some improvement should be noted.

Phenotype assessment is an important process in breeding practice and for studying the influence of genes that shape the productive qualities of sheep. As a result of many years of selection and breeding work, the existing indicators fixed in the breed have lost their supposed potential, which dictates the need to search for new indicators that more accurately characterize the meat productivity of sheep. The aim of the work is to assess the informativeness of phenotype parameters in Russian meat merino sheep by the method of principal component analysis, for further use in genomic selection programs, as well as applicable for in vivo assessment of meat productivity. For the first time, new methods of assessing the exterior and interior for the study of meat productivity have been proposed and their efficiency has been determined for russian meat merino (RMM) sheep. The possibility of determining the size of individual muscle groups using such parameters as the girth of the shoulder, forearm and thigh by instrumental methods, as well as measuring the thigh muscle thickness and fat thickness (TMT and FT) in the lumbar region using ultrasound was studied. The object of the study was the one-year -old rams (n = 50) of the Russian Meat Merino (RMM) breed. To assess the significance of the proposed measurements, in comparison with those used in existing practice, the principal component method and correlation analysis were used. In the course of the work carried out, it was found that measurements: thigh volume, forearm girth had the most significant correlations with all parameters describing the exterior of the PMM breed. Based on the analysis of the main components, it was determined that the first six components in our study explained more than 80% of phenotypic variability. Thus, the proposed parameters determined by ultrasound: TMT and FT are advisable to use for the phenotypic assessment of the conformation of sheep of the RMM breed, especially when searching for genomic associations with productive qualities.

The study of the musculoskeletal system in the morphology of animals, and in particular the topography and functional significance of muscles, is an urgent area among Russian morphologists. Detailed knowledge of the structure, architectonics and function of the somatic musculature greatly simplifies the work of veterinary surgeons, physiotherapists and imaging doctors. The Bastard fox is a member of the canine family and is of particular interest to fur farms because of its valuable fur color. Also, this breed of foxes is popular in private farms, where wild animals are domesticated. In connection with the above, the purpose of our study was to study the anatomical and topographic features of the structure of the muscles of the shoulder girdle of the Bastard fox.

Five corpses of Bastard foxes aged from three to five years, obtained from forced euthanasia from private farms and clinics in St. Petersburg and the Leningrad region, were used as dated material. The study took place at the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. Traditional anatomical methods such as fine anatomical preparation, weighing and morphometry were used as research methods.

According to the results of the study, we found that the muscles of the shoulder girdle of the Bastard fox have a characteristic structure characteristic of carnivores, but at the same time it has a number of individual characteristics.

The object of the study was cows of a black-and-white Holstein breed on tethered maintenance, housed in cowsheds of 200 animals each. Milk productivity per day averaged 36.2 kg per cow. The following main etiological factors of the occurrence and development of finger diseases were identified: violations of the conditions of keeping and feeding cows, lack of regular pruning and clearing of hooves, year-round stable maintenance and lack of exercise. When analyzing the biochemical composition of blood, it was revealed that the protein level in 67% of animals was higher than the normative indicators and was in the range of 89.7 - 91.2 g/l, the reserve alkalinity of blood serum in 86.5% of cows was reduced, which was 33.2 - 41.2 vol%, the ratio between albumins and globulins was violated. Also, 45.7% of the cows studied had a decrease in glucose levels in relation to the normative indicators. A set of measures for the prevention of diseases of the fingers in cows has been developed and its clinical effectiveness has been determined. A detergent and disinfectant called Compomol DS Step antipodermite is proposed for the rehabilitation of limbs in animals. This remedy has not only detergent -antiseptic properties against fresh wounds of the sole of the fingers, crumb, tissues of the arch of the interhoof slit and corolla, but also promotes rapid granulation of wounds, seals the horny wall of the hooves, forms a protective film with a long-lasting antimicrobial effect. The results obtained in production conditions indicate that the double use during the week of foot baths with a 5% solution of Compomol DS Step antipodermite reduces the incidence of limbs in cows by 26.3%, compared with the use of a 5% solution of copper sulfate.

The biochemical blood profile is one of the tools for monitoring the feeding and keeping of animals, and their state of health. However, it requires clarification for individuals reared both in different climatic conditions and operated under different housing systems. In this regard, the purpose of our study was to assess the temporal changes in the levels of circulating metabolites and the activity of enzymes in the first-flowing Saanen goats in the first two months of lactation, reared with intensive maintenance technology in the climatic conditions of the North-West region of Russia. Blood sampling from primiparous goats (n = 32) was carried out twice: on days 20- 30 and days 50-60 after lambing (MayJune). In the blood serum, the concentration of total protein, albumin, urea, creatinine, glucose, total cholesterol was determined, as well as the activity of enzymes: aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). It was found that by the end of the second month of lactation, the most significant changes occurred in lipid metabolism. Thus, the concentration of triglycerides and cholesterol in the blood increased by 71% and 11% (p˂ 0.001). The change in the parameters of protein metabolism was less dynamic: the content of total protein, creatine and albumin increased by 7.4%, 10.8% (p˂ 0.001) and 2% (p˂ 0.05), respectively. ALT activity increased by 19% (p˂ 0.001). Comparative analysis of blood biochemical parameters of the first and second months of lactation showed a positive dynamics of the process of adaptation of primiparous goats. The obtained values of blood biochemical parameters can be used to establish basic physiological values for 1-2 months of lactation in primiparous goats. This will facilitate a realistic assessment of the management, nutrition and health status of Saanen goats reared in large livestock facilities.

The importance of trace elements in the nutrition of young farm animals is extremely high, since they participate in the regulation of basic physiological processes, and also serve as activators of enzymes of structural elements. In order to achieve good growth and development indicators of young cattle, it is necessary to optimize their mineral nutrition. In this regard, it is necessary to study the effect of certain mineral substances (Co, Se, I, Mn, Zn) in early postnatal ontogenesis on the clinical and hematological parameters of the body of calves.

The research was carried out in 2021 on black-and-white cattle on the basis of the Department of Veterinary Medicine of Astrakhan State University. Determination of the levels of trace elements in the ecosystem was carried out in the Astrakhan region. In addition, 6 heads of black-and-white cattle were selected. Samples for the study were taken from animals aged from 1 to 6 months. Determination of hematological parameters of animals was carried out on the IDEXX Laser Cyte analyzer (USA), biochemical parameters – on the IDEXX Catalist analyzer (USA).

The conducted studies have shown a low level of some trace elements in the ecosystem of the Astrakhan region. The greatest amount in soil and plants contains manganese and zinc, the least – selenium. However, the lack of certain minerals in early postnatal ontogenesis does not affect the hematological parameters of the calves' body. All the studied parameters were within the limits of physiological norms, which may be associated with the long-term pathogenesis of microelementoses in animals.

The study of the features of the morphology of the heart and its structures in farm animals in species and breed aspects is an urgent direction in fundamental research. Anglo-Nubian goats are a versatile goat breed, and currently their breeding is gaining popularity in the North-West region of the Russian Federation. Due to the capriciousness of this breed of goats to cold temperatures, they can often suffer from diseases of the cardiovascular and respiratory systems. The purpose of our study is to establish the histological features of the structure of the interventricular septum of the heart of an Anglo-Nubian goat.

Eleven corpses of Anglo-Nubian goats obtained during slaughter in the farm of the Moscow region of the Russian Federation "Gzhelpodvorie" were presented as the material under study. The age of the corpses of Anglo-Nubian goats was 12-13 months. As research methods were used: fine anatomical preparation and manufacture of histological preparations.

We found that the composition of the interventricular septum of the heart of an Anglo-Nubian goat contains contractile cardiomyocytes, strands of loose unformed connective tissue, muscle and mixed blood vessels, nerve trunks, a few Purkinje fibers, as well as the endocardium. Also established morphometric data of histostructures of the interventricular septum in a goat of the Anglo-Nubian breed.

In modern broiler poultry farming, the problem of different rates of formation of muscle and connective tissue has become increasingly common. To a greater extent, this problem is affected by highly productive crosses of broiler chickens (Ross-308, Cobb500), whose selection is aimed at accelerated recruitment of live weight, without taking into account the development of the backbone and joints. According to Russian and foreign authors, during the period of broiler cultivation, the rate of poultry culling is on average 10%. Of these, more than half are pathologies of the musculoskeletal system, both non-infectious (injuries, unbalanced diet in terms of macro-and microelement composition) and infectious (reovirus tenosynovitis) etiology.

Our study presents the results of an experiment to study the effect of silicon dioxide and dihydroquercetin on the zonal structure of the articular cartilage of the femoral head of broiler chickens in the age aspect. The object of the study was broiler chickens of the Ross-308 cross. 160 head of chickens on the whole were examined. During the experiment, four groups of chickens with 40 chicks each were formed according to the principle of analogues. The first group was a control one and received the main diet until the age of 38 days, the chickens of the second, third and fourth groups were fed with feed additives "Covelos-Sorb" in the amount of 0.1 g, 0.14 g and 0.18 g/ 1 kg of live weight per day respectively and "Ecostimul2" in the amount of 1 mg/1 kg of live weight per day. As a result of the study, it was found that the change in the thickness of the structural zones of the articular cartilage of the broiler chicken femoral head is periodic and asynchronous, depending on the age, individual characteristics and dosage of biologically active supplements. There was also an increase in the proportion of isogenic groups in the intermediate zone of the articular cartilage of the femoral head in experimental chickens, which may indicate an increase in the activity of chondrogenesis.

In experimental researches, ferrets are used as model animals – an alternative to larger predators and rodents in studying various pathologies. Ferrets are exotic pets, and the effect of their domestication manifests itself in the development of various cardiovascular diseases. An electrocardiographic study allows to reveal already acquired heart pathologies such as arrhythmias in adult small animals. The most striking physiological adaptation to new living conditions is observed in ferrets in the early postnatal period. Knowledge of characteristics of the ferrets’ electrocardiogram during this period will help to identify congenital cardiac diseases. The aim of the study was to examine electrocardiograms of ferrets at the age of one month and compare the results obtained with adult small animals. Electrocardiograms were recorded in standard bipolar limb leads on a 12-channel computer electrocardiograph in the sternal body position. The analysis of the morphology of the P-wave, QRS complex, and T-wave was carried out, the characteristics of the amplitude indicators and time intervals was presented. It was revealed that the P-wave was predominantly peaked with the highest amplitude in the second lead, the complex of initial ventricular activity was represented by a singlephase R-wave; in some animals, the T-wave was biphasic in leads II and III. A high elevation of the ST segment was recorded on the electrocardiogram of all the small animals. The results obtained showed that significant changes were not observed in the electrocardiogram of one-month-old ferrets in comparison with adult healthy small animals, so their electrocardiogram described can be considered normal for their age.

On the basis of the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine, we examined 10 corpses of sheep of the Edilbaevsky breed aged one year and older. The cadaverous material for the study was samples of the jejunum of sheep of the Edilbaev breed. In the course of the study, histological and morphological data were obtained and processed, as well as features of the histostructures of the jejunum wall of sheep of the Edilbaev breed in postnatal ontogenesis were revealed. In our study, a complex of traditional histological methods and staining was used: hematoxylin-eosin and Masson trichrome. Violations of the trophism of the jejunum can lead to incomplete development of the organism as a whole, and in rare cases to a fatal outcome, leading to economically unprofitable situations in sheep farms. The lean book of sheep is a segment of the small intestine, in which not only band, wall digestion is carried out, but also the absorption of a large part of nutrients, micromacroelements, vitamins and water, as well as the area where diseases such as inversion and intussusceptions of the intestine are most common. As a result of the study, it was concluded that the walls of the jejunum of sheep of the Edilba breed aged one year and older have a similar structure with a similar type of digestive system in other ruminants. Morphometric data have been established, in particular, the thickness of the intestinal membranes, the thickness and height of the villi, the depth of the crypts in this breed of sheep, which may vary from a certain load of the digestive apparatus.

The industrial form of pig rearing and breeding implies a significant degree of intensification of all technological processes to obtain the greatest benefit with the lowest economic costs. All this is aimed at solving issues of food supply, import substitution in compliance with the rules of veterinary and sanitary safety. However, during the transition of pig breeding to intensive industrial technology, there is an incomplete compliance of the physiological needs of animals with technological requirements, as a result of which a potential decrease in productivity, resistance, and the development of internal diseases is possible. The main organ involved in all metabolic processes of metabolism is the liver. The purpose of the presented study was to evaluate the effect of the feed biologically active additive "Vetlaktoflor" on the biochemical parameters of the blood in pregnant sows. To study the effect of the "Vetlaktoflor", 4 groups of sows were formed. One control group without the use of the agent and 3 experimental groups where the agent was used according to the following scheme: experimental group -2 - animals were given the active additive "Vetlaktoflor" 2 weeks before farrowing, experimental group-3 - animals were given the active additive "Vetlaktoflor" 2 months before farrowing, experimental group-4 - animals received the biologically active additive "Vetlaktoflor" twice during pregnancy: 2 months and 2 weeks before farrowing.

As a result of the use of a biologically active additive, the stabilization of the activity of serum enzymes AlAT and AsAT was noted. In the experimental groups, the activity level of these enzymes was lower by 43.93-67.32% and 30.91-52.56%, respectively. Thus, the probiotic "Vetlaktoflor" is effective when used during pregnancy, reducing the degree of endogenous load on the body of pregnant sows, as well as keeping the level of these enzymes within the reference values, which indicates the stabilization of the state of hepatocellular metabolism.

In the agro-industrial complex livestock sector the tendency to reduce the use of antibacterial agents in production is increasing. In this regard, the use of probiotics is gaining popularity around the world. Being antagonists of pathogenic and opportunistic intestinal microorganisms, suppressing their growth and reproduction, as well as creating favorable conditions for the obligate microflora of the gastrointestinal tract, probiotics are becoming increasingly important. The feed biologically active additive "Vetlaktoflor" belongs to the preparations of this group.

The purpose of the presented work was to study the effect of the feed biologically active additive "Vetlaktoflor" on the biochemical parameters of the blood of pregnant pigs. To study the effect of the drug, 4 groups of sows were formed. One control group without the use of the drug and 3 experimental groups where the drug was used according to the following scheme: experimental group-2 - animals were given the active additive "Vetlaktoflor" 2 weeks before farrowing, experimental group-3 - animals were given the active additive "Vetlaktoflor" 2 months before farrowing, experimental group-4 - animals received the biologically active additive "Vetlaktoflor" twice during pregnancy: 2 months and 2 weeks before farrowing.

As a result of the use of a biologically active additive, stable values of total protein and its fractions, urea, creatinine were noted. At the same time, the increase in total protein values increased in the range from 16.12% to 17.01%, albumin values increased to 62.10%, globulin values increased to 34.96%. Indicators of urea and creatinine with a slight increase remained within the reference values. Thus, the probiotic "Vetlaktoflor" is effective when used during pregnancy, stimulating the processes of protein metabolism, thereby ensuring a stable course of pregnancy. With intensive nitrogen metabolism characteristic of pregnancy, this biologically active additive ensures that urea and creatinine indicators are found within the average reference values.

The study was conducted on 15 dogs aged 1.5-12 years, kept in urban conditions with symptoms of chronic stress caused by various factors: moving to a new place of residence, fear of loneliness, loss of the owner, exhibition career, active breeding activities. The drug Klim Peter was given to all animals for 21 days at a dosage of 1 tablet per 10 kg of live weight 1 time per day. Blood samples were taken for morphological and biochemical studies before the start of the study and after the use of the drug (on the 24th day from the start of the experiment). The drug contributed to a significant reduction in the initially elevated level of white blood cells, the number of red blood cells and the concentration of hemoglobin, a decrease in ESR. The ratio of white blood cells in the leukogram approached the standard values. Protein and albumin levels were significantly increased.The normalization of anabolic processes was confirmed by a decrease in urea and creatinine levels, as well as a significant decrease in the level of bilirubin and the activity of enzymes – ALT, AST and alkaline phosphatase. After 5-10 days after the start of taking the drug, the animals showed normalization of appetite and digestion, after 14-18 days, neurological symptoms were leveled (destructive behavior, tremor, unmotivated aggression, obsessive behavior). By the 20th day, there was an improvement in the condition of the skin and coat, molting in most stopped or decreased, the coat became thick, shiny. Thus, the use of the drug Klim Pet had a positive effect on the clinical condition, and also helped to neutralize the effects of stress factors of various etiologies, had a hepatoprotective effect, optimized the metabolism and activity of the immune and nervous systems, contributed to improving the condition of the fur and skin.

Pig breeding is one of the leading farm industries for the production of meat products. Castration is one of the techniques that help to increase the productivity of animals and regulate the quality of meat (eliminating the “smell of boar meat”). Its disadvantage is the presence of post-castration complications. An effective method of reducing their number is the use of drugs that have an immunotropic effect.

Therefore, we conducted an experiment to find out the effect of one of this drug group representatives (timogen) on the dynamics of hematological parameters during castration of boars.

The data of hematological studies (during the experiment) signified a violation of homeostasis, manifested in the first fourteen days after castration by the development of anemia (a decrease in the number of erythrocytes and hemoglobin) and thrombocytopenia, which (like erythropenia) was recorded against the background of anisocytosis. At the same time, the results, reflecting the picture of white blood, indicated an inflammatory process accompanied by leukocytosis, due to both the absolute and the relative number of lymphocytes, as well as the absolute number of medium-sized cells (MID). On the 30th day of observation, an increase in the number of erythrocytes and hemoglobin relative to the 14th day was noted against the background of a decrease in platelets and leukopenia.

Thus, immunocorrection with a five-day course of timogen made it possible to neutralize the negative effect of surgical intervention on hematopoiesis, which allowed us to avoid sharp fluctuations in the morphological composition of red and white blood.

During pregnancy, calving and milking, the body of cows experiences stress, which leads to a decrease in productivity and disruption of metabolic processes, and as a result to significant economic losses of milk producers, as well as to premature culling of animals.

The developers offer various feed additives that help limit the manifestation of stress, one of them is the organomineral Klim supplement, consisting of organic acids and mineral components, with the properties of a universal adaptogen.

The study was carried out on cows of the Leningrad region livestock farm, and the effect of the Klim supplement on the general clinical condition of cows and metabolic processes by biochemical blood analysis was taken into account.

According to the results of the study, it was revealed that the Klim feed additive we studied, developed for use in cattle, had a positive effect on the nature of metabolic processes in cows during the difficult period of late pregnancy and the early period after calving. The drug helped to reduce the excess content of under-oxidized metabolic products in the cows of experimental animals, leading to the development of acidosis and eventually ketosis. We also noted the normalization of protein metabolism. In addition, the exterior of the animals was improved. Against the background of the use of the Klim supplement, ruminants also adapted faster and easier to changes in the external environment.

As a result, it was found that the completion of the recovery of the ovarian function (the first ovulation after parturition) in cows is observed within 28.4±7.32-39.3±12.54 days after parturition, and the period from calving to the completion of uterine involution is from 44.5±9.37 to 58.2±10.56 days, depending on the productivity of animals. The maximum fertilization rate in cows with a milk productivity of 15-20 liters/day was 56.7% when they were inseminated in their third heat, in animals with the productivity of 25-30 liters this indicator was significantly lower - 34.7%.

Abnormalities in follicular genesis were revealed, which were characterized by the retardation in the development of follicles, and the absence of a dominant follicle. No yellow body and follicles were found in the ovaries, or, if follicles were found, their diameter ranged from 6 to 10 mm. The ovaries were slightly reduced in size: their length was about-3.21 cm and width-1.85 cm. Thereafter such follicles were subjected to luteinization or atresia.

In the course of studies on the 14th day after parturition, a low level of progesterone was found, almost 2 times (1.27 +0.19 and 0.67 +0.09 nmol/l), in the blood serum of cows with a daily milk yield of 25-30 liters or more. On day 30, the difference in the content of estradiol was 2.4 times (128.41+16.92 and 53.70+ 6.53 nmol/l, respectively) and progesterone-2.9 times (3.53+ 0.22 and 1.2+10.12 nmol/l) in cows in groups with different milk productivity. This indicates the fact that with a low level of progesterone, there is retardation in the recovery of the reproductive function in high yielding dairy cows after parturition due to the functional disorders of the ovaries and focuses on the need to use hormonal regulation during this period.

Analysis of the results of medical examination of pregnant sheep 30...15...5 days before the expected term of lambing showed that in the urine of 12.11% of ewes, the concentration of ketone bodies in the blood plasma was 1.43 times higher than the physiological norm. In addition, there is a tendency to decrease the buffer bases to 18.41±1.53 mmol/l, as well as the glucose content below 2.12 ± 0.12 mmol/l. At the same time, the ratio of VN/ ACAS is up to 1.47 ± 0.12 mmol / L. It was found that the albumin fraction of proteins decreased by 1.51 times. Edema in the abdominal wall and underbelly, 9.5% lack of reaction to external stimuli, 15.0% decreased appetite, 10.0% jaundice of mucous membranes and 9.0% of sheep had a comatose state were found in 15.0% of animals. In a clinical study in sheep with eclampsia, hypertension over 136.1 mmHg and the presence of protein in urine over 3.2 g/l were recorded. These symptoms indicated classic signs of eclampsia, which occurred depending on the condition of sick animals in atypical and typical forms of manifestation. In animals with typical clinical signs of eclampsia, an increase in the level of diene conjugates was found to be 1.87 times, and the concentration of ketodiene intermediates and conjugated trienes was 1.75 times, the concentration of stable nitric oxide metabolites was 38.0%, and the vitamin E content decreased by 13.1%. At the same time, there was a 20.46% increase in the concentration of double bonds in the atypical form of eclampsia. In the blood plasma of patients with eclampsia of pregnant ewes, the activity of superoxide dismutase (1,736±0.37 units) is lower than in the comparison group (2,146±0.56 mmol/l). The obtained material of this work should be taken into account in the future when studying the problem of complicated pregnancy in the last stages of gestation in sheep and when developing therapeutic and preventive measures to ensure the long-term functioning of the reproductive potential and obtaining a viable newborn offspring.

The paper presents the results of a clinical and experimental study of determining the clinical effectiveness of surgical treatment of animals with patent ductus arteriosus using open ligation and endovascular occlusion using the example of dogs of the Corgi and Spitz breeds. A retrospective study, the morphofunctional state of the cardiovascular system was assessed before and after surgery. The total sample consisted of 25 animals. Diagnosis of this defect was carried out by auscultation and using echocardiography [ultrasound]. During auscultation, a systolic-diastolic murmur is heard. On ultrasound, the normalized parameters were compared before and after surgery. Animals with critical pulmonary hypertension were excluded from the study, since this complication is a contraindication for surgical treatment. In the postoperative period, the animals after open correction of the defect recovered longer and needed more prolonged analgesia than animals after endovascular treatment. After open treatment with thoracotomy, the animals were in the intensive care unit for a day, and after transcatheter surgery - 6-12 hours. After that, all animals were discharged for outpatient treatment. After closure of the duct, all dogs with a congenital defect became more active, their general condition improved, shortness of breath during physical exertion disappeared, and the respiratory rate decreased significantly. It was found that corgi are more difficult to tolerate this defect than Spitz dogs. They had a more frequent complication in the form of pulmonary hypertension. One year after the surgical treatment, when performing echocardiography, the indicators of the morphofunctional state of the heart were normalized.

The objective of this study was to compare three different local anesthetics in terms of duration and effectiveness of block development in brachial plexus block for osteosynthesis of radius with plate in dogs. The blockade was received a electroneurostimulation-guided Stimuplex HNS 12 with SENSe function by B. Brown for all group. 15 dogs of smallest breeds were divided into three random groups: in the first, 2% lidocaine solution was used as anesthesia; in the second bupivacaine 0.5%, in the third ropivacaine 0.5%. The time to development and the duration of the local block were assessed with a pinch method in several areas. The fastest development of a complete limb block was observed in group 1, which took an average of 7-10 minutes. The development of a complete block in the 2nd group exceeded three times, and in the 3rd - twice, the anesthetic indicators of the 1st group. All patients from group 1 were immediately injected with analgesics after surgery to relieve postoperative pain. The duration of the blockade of the third group was significantly shorter than in the second group, however, the motor block in the second group was significantly longer than in the 3rd group, patients experienced pain, but the motor function of the distal limb has not yet recovered. Thus, ropivacaine, by its properties, is the drug of choice for brachial plexus blockade for periosteal osteosynthesis of the forelimb in dogs and can be used for surgeries longer than 80 minutes.

Purpose: The aim of the research is to study the effect of subclinical ketosis (SCK) on the effectiveness of artificial insemination of highly productive dairy cows in the postpartum period.

Materials and methods. The studied animals were selected according to the principle of conditional analogs and were divided into 2 groups of 6 animals each. Group 1 - animals with a blood concentration of 3- hydroxybutyrate˂ 1.0 mmol / l, group 2 - animals with subclinical ketosis with a concentration of 3-hydroxybutyrate in the blood in the range of 1.0-1.4 mmol / l. Blood was collected from animals on the 5th, 15th and 33-35th days after calving. In the obtained blood serum samples, the content of total protein, albumin, urea, glucose, cholesterol, triglycerides, calcium, phosphorus, magnesium, creatinine, total bilirubin, the activity of transaminase enzymes and alkaline phosphatase was determined. The concentration of steroid hormones has been determined. Before artificial insemination, the animals were synchronized according to the pressinovsinh scheme.

Results. Most of the biochemical blood parameters did not go beyond the reference values. By the time of hormonal stimulation of sexual heat in cows with SCK, a decrease in 3-hydroxybutyrate (˂ 1,0 mmol / l) and an increase in glucose (> 3.0 mmol / l) were recorded. On the 15th day after calving, in the group with SCK, there was an increase in total bilirubin, cholesterol, triglycerides, and magnesium (p˂ 0,01). On the 15th day after calving, testosterone levels were 13% higher in the SCK group. By the time of synchronization, the level of progesterone in the group of animals with SCK was lower in comparison with the control group. In the group of animals with SCK, the lowest reproductive indices were recorded: the insemination index in the group with SSC was higher by 46%, the service period was 49 days longer, the interbody period was significantly longer by 68 days (p˂ 0,05).

Conclusion. Subclinical ketosis, recorded on the 15th day after calving, helps to reduce the reproductive performance of high -yielding dairy cows. Normalization of the concentration of 3-hydroxybutyrate from subclinical to physiologically normal values, and subsequent hormonal synchronization do not reduce this negative effect of SCK.

The international scientific conference was dedicated to the 100th anniversary of the Department of Pathological Physiology of the St. Petersburg state university of veterinary medicine. The audience was presented with a historical reference about the department and its first head – prof. London E.S., also scientific schools were characterized and an idea of the current state of the department was given. The conference discussed issues of general etiology and general pathogenesis of animal diseases, pathogenetic foundations of non-infectious diseases, considered various experimental models in pathology and paid attention to the discussion of teaching pathophysiology and the introduction of digital technologies in the educational process in modern conditions. The holding of the event in the format of Zoom video conferences with the broadcast of meetings on YouTube gave an opportunity to participate as a listener to a wide range of interested persons.