1.A study to determine the effectiveness of the drug "Aziflumin". “Aziflumin” is part of the Macrolide group and contains the active substance azithromycin in dihydrate form (100 mg in 1 ml). The drug was carried out on black-and-white calves with cryptosporidiosis, from 3 days to 1 month of age. After the diagnosis of cryptosporidiosis was confirmed in calves with signs of diarrhea, dehydration and cachexia, the animals were split into 3 groups of 10.The drug "Aziflumin'' was injected intramuscularly, once a day, at a dose of 1 ml per 20 kg of body weight to animals in group No. 1 for 5 days and to calves in group No. 2 for 7. The third group received symptomatic treatment. Evaluation of the effectiveness of the drug was carried out on days 7, 14 and 21 from the beginning of treatment.To identify the possible side effects "Aziflumin" could have on calves under 2 months of age going through a treatment of this kind, we analyzed the results of the  clinical and biochemical blood tests of groups No. 1 and No. 2. It was found that the drug "Aziflumin" has a therapeutic effect for cryptosporidiosis in calves, which is most pronounced after a 7-day course of therapy. A 5 day course is less effective, because on the 21st day from the start of the treatment with "Aziflumin", cryptosporidium oocysts were found in the feces of 2 calves from group No. 1. In animals receiving the drug for 7 days, no oocysts of the genus cryptosporidium were found on day 21. The use of the drug contributed to the functional stabilization of the gastrointestinal tract and did not cause any allergic or toxic reaction, and the calves experienced no other side effects, which was confirmed by monitoring the condition of the animals and by the results of clinical and biochemical blood tests. 

 To maintain sustainable veterinary welfare, food and economic security of the country, it is necessary to create new highly effective medicines.
The problem of improving the quality and safety of livestock products indicates the advisability of developing medicines aimed at combating ectoparasites of farm animals, because in some zones of Russia, including Siberia, this problem is very acute. A prerequisite for the use of new drugs in
veterinary medicine is the prior conduct of toxicological studies on laboratory animals. The article presents data on the study of the acute toxicity of the drug Delcid 7.5® when administered by cutaneous  administration in white male rats. The drug is manufactured by LLC NVC Agrovetzashchita, it is an oily transparent liquid in the form of a solution for external use. As active ingredients it contains: deltamethrin - 7.5 mg,  diflubenzuron - 3 mg and piperonyl butoxide - 1.5 mg, as well as auxiliary  substances: butylhydroxytoluene, butylhydroxyanisole, diethylene glycol  monoethyl ether. In the course of the research, a clinical ex amination of the animals was carried out. Observations were carried out for changes in
the condition of the skin and hair, eyes, mucous membranes, respiratory,  circulatory, autonomic and central nervous systems, somatomotor activity and behavior. At pathological autopsy, attention was paid to the state of the internal organs. The parameters of the acute toxic effect of the drug were
calculated. The maximum tolerated dose, absolutely lethal and average lethal dose (LD50) of the drug Delcid 7.5® in male rats have been established. According to the degree of impact on the body according to GOST 12.1.007-76, this drug belongs to the 3rd hazard class - moderately hazardous substances.

 The base of the complex consists of three carefully selected sorbents: perlite, polyphepan and vermiculite. The phyto components were used from previously conducted tests both in vivo and in vitro: thyme herb, chamomile  flowers, elecampane rhizomes and root, wormwood, juniper berry oil and oregano oil. The research was carried out in the Smena agricultural enterprise in the Pushkinogorsk district of the Pskov region. For this purpose, the monitoring of the content of heavy metals in the soil and the main feed of the diet of calves 2 months of age was carried out. Were selected 10 animals, with the same conditions of keeping and feeding.  One  group of animals served as a control (n = 5), in the second group, in addition to the diet, a phytosorption complex was added at a dose of 4% of the main diet. The experiment lasted 14 days. At the end of the experiment, the animals were slaughtered and samples of muscle tissue and parenchymal organs were taken to determine the amount of heavy metals.  The presence of heavy metals was determined by the periodate method and  by the method of atomic adsorption spectrometry. An experiment on the effect of the phytosorption complex on the accumulation of heavy metals in the organs and tissues of animals showed that the content of cadmium in the muscle tissue of calves in the experimental group was less by 25%, in the liver by 28.5%, in the kidneys by 52%, compared with the control. This experiment showed the prospects of introducing a phytosorption complex into the diets of farm animals to obtain environmentally friendly products. Along with this, it is necessary to monitor the environment and draw up specific feed additives, sorption complexes and recommendations for their use for each disadvantaged  area. 

 Restoring the fertility of cows is an urgent task in the intensive use of breeding stock. The aim of the research was the complex use of hormonal  drugs in combination with sinestrol to stimulate the reproductive function of cows. The research method was used for cows of the experimental (n15) group that did not come to the hunt for a long time after childbirth (90-105 days) according to the standard scheme: biostimulant in the 1st, 3rd, 5th day, sinistral – 1,3-day, progesterone – 5 th, 12 th days, polimag – once on the 7th day of the experiment. The experiment lasted 89 days (from 03.08 to 30.10 2020).
The effectiveness of stimulation of the reproductive system was determined by  the timing of the manifestation of hunting and the results of insemination-by the definition of pregnancy. The result of the experiment on the complex use of hormonal drugs was very positive: 11 cows (73.3%) came to the hunt and fruitfully inseminated for the first time, they were found to be pregnant, 4  cows  (26.7%) came to the hunt after 26-30 days with a repeat of 18-21 days, of which 2 after insemination turned out to be pregnant (13.3%). As a result, the  restoration of sexual cyclicity occurred in 13 cows (86.6%), which indicates the high effectiveness of the use of a complex scheme of hormonal drugs in restoring reproductive function in cows.
This scheme of stimulating the reproductive function is recommended to farms of the Smolensk region to eliminate infertility in cows. 

 Fragments of peptidoglycans, namely muramyl peptides, induce a complex cellular response through the activation of pattern recognition receptors. Over the past two decades, many structural sequences have been discovered that bind PG (proteins containing LysM; intracellular regulatory proteins of  NOD-like receptors; proteins that bind the domain with penicillins and Ser / Thr-kinases; peptidoglycan recognition proteins; lectin-like receptors of C -type; eukaryotic  cytosolic hexonicases). It has been shown that the use of muramyl peptides is an effective tool for modulating the cellular response, and for enhancing the production of proinflammatory cytokines in particular. The cytotoxicity of peptidoglycan fractions against various types of tumors, including sarcoma, leukemia, melanoma, and lung cancer, has been revealed. The tumor activity of  muropeptides with antiproliferative and cytotoxic effects is associated with modulation of cytokine and chemokine production. It is especially significant that muramyl peptides are able to reduce the bioenergetic ratio of mitochondria as an anomaly of energy metabolism, associated with a tumor, may be the cause of suppression of cancer processes. Under natural conditions of environmental pollution, the immunomodulatory effect of the enzymatic hydrolyzate of the cell wall of Lactobacillus delbrueckiiis manifested the complex stimulation of the humoral and cellular links of the immune response, which was confirmed by an increase in the bactericidal and lysozyme activity of colostrum. The use of such immunomodulators can be a promising basis for regulation of the mechanisms of immune resistance, maintaining health and increasing the weight gain of animals for the first weeks of life. 

 At the meeting of the Pharmacopoeial Committee of the Eurasian Economic Union (EAEU) in 2017, it was proposed not to include the test for abnormal toxicity in the draft of the EAEU Pharmacopoeia, the basis for this discussion was the refusal of the European Pharmacopoeia from this test. Currently,  such a step cannot be taken on the territory of our country, on the grounds that not all production of medical and veterinary drugs meet international GMP requirements. The main purpose of the test for abnormal toxicity is to identify the toxicity of the drug in excess of the previously established permissible level, controlled by increasing mortality or by unregulated  phenomena of ani mal intoxication. The test makes it possible to determine the increased toxicity of a medicinal product, which may arise due to the appearance of decomposition products or undesirable impurities in the event of a violation of the production process, transportation or improper  storage of the drug. 
The aim of these studies was to develop a method for controlling the quality of the LArginine substance. Studies on the indicator "Abnormal toxicity" were carried out in accordance with the requirements of the State Pharmacopoeia of the Russian Federation XIV ed., V.1., M., 2018, section "Abnormal toxicity" (OFS.1.2.0004.15), according to which the drug is considered to have passed test for abnormal toxicity if the total death of animals in the test performed on 10 mice does not exceed 10% [1].
Based on the main objective of this test - to reveal the abnormal toxicity of the test substance L-Arginine, it was considered expedient to recommend its  maximum tolerated dose as a test dose, i.e. the dose, with the introduction of which there is no lethality, pronounced clinical phenomena of intoxication or the observed phenomena of intoxication are manifested for a short time and very weakly.
 

 At livestock farms and large dairy farms in the Smolensk region, despite the implementation of preventive measures in the premises, their sterility cannot  be achieved. Conditionally pathogenic microflora is constantly present in the environment of cows, which is the root cause of mastitis. With a decrease in the overall resistance of the animal body, the virulent microorganisms that appear cause breast pathology. Annual milk yields are decreasing, and farms are forced to cull a significant number of cows.
According to statistics, from 40 to 60% of cows in the herd suffer from subclinical and from 10 to 25% of clinical mastitis. A similar level of morbidity of cows with mastitis is observed in the farms of the Smolensk region.
For the treatment of mastitis, the same drug is often used for 2-3 years, which leads to the appearance of resistant strains of microorganisms to such a drug. Only a systematic annual change of the therapeutic agent ensures successful  treatment of mastitis.
We performed an experiment on the use of a new domestic complex drug triolact in the experimental group (n-15) in comparison with primalact in the control group (n-12). The presence of semisynthetic antibacterial groups of penicillins in triolact – amoxicillins and cloxacillin, prednisolone provides a wide antibacterial spectrum of action.
The diagnosis of mastitis was carried out in accordance with the "Guidelines for the diagnosis, therapy and prevention of mastitis in cows" - 2007 using the masttest. In secret, the species composition of the microflora was determined from the affected udder lobes.
The obtained experimental data showed a high therapeutic effectiveness of the newly used triolact in the farm in comparison with primalact. In three days, 13 cows (96.7%) recovered, which is 21.7% more animals than from primalact in the control.
The experimental studies performed indicate the high therapeutic effectiveness of the new drug triolact in comparison with the primalact used in the farm. 

 The widespread occurrence of filamentous fungi of the genus Fusarium is a very dangerous mold micromycete. Mold isolate of the genus Fusarium can manifest itself in all climatic areas. The micellar fungus is capable of infecting the vascular system of plants, germinated grains, tree roots, and vegetable crops. When tissues are damaged by fungi of the genus Fusarium, plants, as a rule, wilt and begin to rot. Spores and particles of mycelium of the fungus can be localized for  a long time on the surface of the soil, in water, in plant residues, affecting
immature seedlings of grain and agricultural crops. High humidity, lack of daylight hours and temperature drops have a beneficial effect on the toxin  formation of fungi of the genus Fusarium. As an experiment, soil isolates of fungi of the genus Fusarium (Fusarium sporotrichioides) showing the toxin formation of T-2 toxin were selected.
The prepared grain substrate was contaminated with field isolate and exposed  to temperature fluctuations, artificially creating stress for the micromycete. The weediness, growth, and color of mold on different types of grain crops were visually recorded. In addition, suspensions with lactose, beckon, and dimethyl sulfacid were added to the extract to improve growth and toxin formation.
The aim of this work was to study an isolate of the genus Fusarium (Fusarium sporotrichioides) in obtaining T-2 toxin, use for laboratory purposes as a test object and to replenish the collection of microorganisms. 

 In intensive conditions of keeping animals without the use of additional top dressing, premixes, biologically active additives, it is almost impossible to achieve maximum productivity of animals. Important the reason for this is metabolic disorders. As a result of metabolic disorders in animals, the  immune status of the body decreases, as a result of which they become susceptible to various diseases, reduced fertility, the birth of weak offspring, reduced productivity, etc. Therefore, modern technologies of feeding farm animals, provide for the active use of premixes and other biologically active  substances to the main diet. The purpose of this study was to study the hematological composition of the blood of dairy cows when using the UVMC "Khazine-lizunets". It is known that the indicator of metabolism in the body of animals is blood. It constantly circulates in a closed system of blood vessels and performs a transport, protective and regulatory function in the  body of animals. For this purpose, we conducted experiments on clinically healthy dairy cows of the black-and-white breed in the conditions of the farm of LLC "Igenche" of the Tyulyachinsky district of the Republic of Tatarstan. In the experimental animals,  the general clinical condition, the amount of feed intake, the lizun and the state of hematological blood parameters were evaluated. It was found that the use of UVMC "Khazine-lizunets" in dairy cows at the stage of milking at a dose of 181,2±0,47 g per day for thirty days has a positive effect on their hematological parameters of blood composition. It was found that in animals, when using this feed additive, the feed consumption increases by 3,5%. There is an improvement in the clinical condition of the body, due to the content of vital nutrients in the composition of the UVMC "Khazinelizunets". It was revealed that the  hematological parameters of the blood were within the physiological norm. 

 Rational control of the red chicken mite should be based on the selection of means and methods of their use, which provide the best both therapeutic and prophylactic efficacy. 
The aim of our research was to study the acaricidal activity of emulsions based on etofenprox and juvenile hormones on D. gallinae mite. Two series of experiments were carried out. For this, Petri dishes were used, on the bottom of which were placed D. gallinae. The edges of the cup were treated with petroleum jelly in order to limit the mobility of ticks and keep them in the observation area. After that, the emulsions of the preparations were applied directly to the ticks by the method of small-drop spraying.
For further experiments, an MBS-10 microscope was used and observations  were made of the viability of ticks with fixing their 100% death. The test objects were continuously monitored for the first 3 hours, then every hour. After 12 hours of the study, observation and recording of the results occurred every 2 hours. One day after the start of the experiment, the objects in Petri dishes were observed once a day. The control of this experiment was Petri dishes with red chicken mites, treated with a mixture of auxiliary components, used in working  solutions of drugs of this group.
As a result of the studies aimed to study the direct acaricidal action of emulsions based on etofenprox and juvenile hormones, it can be concluded that in a double test, emulsions of drugs in 2% concentration showed the greatest efficiency: etofenprox and smethoprene, etofenprox and pyriproxifen. 

 Salmonellosis is a serious pathology of infectious origin, leading to high economic losses in poultry farming. A particular danger of the disease is that infected poultry may be a hidden bacterial carrier, and salmonellosis is also a threat to humans. For preventive, as well as therapeutic measures, antibacterial drugs are used, one of which is a representative of fluoroquinolones – Enrofloxacin. Despite the data on the good  antimicrobial effect of the drug, little research has been conducted on its impact on the physiological condition of birds, in particular, the impact of Enrofloxacin on  white blood. For the study four groups were formed, from which II and III received Enrofloxacin in doses of 200 mg/l and 100 mg/l, while I and IV – normal drinking water, and groups II, III, IV were experimentally infected with Salmonella infantis culture in the concentration of 30 million COE/0.5 ml. Blood samples were taken on the 1st, 3rd, 5th, 7th and 9th day after the drug withdrawal. The following parameters  were studied: blood leukocyte content, leukocyte formula, and dynamics of leukocyte indices. The revealed changes in all experimental groups testify to the ambiguous antibacterial effect of the use of Enrofloxacin, although the use of 200 mg/l dosage, to some extent, was more effective. Nevertheless, on the whole, in spite of the revealed reliable shifts of the studied indicators in chickens of the experimental groups, no negative effect of the preparation on the cockerels' organism was revealed. 

  Microscopic fungi pose a significant danger to animal and human health, because their ability to produce mycotoxins are highly toxic, mutagenic, teratogenic and carcinogenic. The intestinal tract is the first defense of the organism against the ingress of contaminants. The gut microbiota can vary  within a species, so different responses to mycotoxin can be observed. High  concentrations of contaminants such as mycotoxins can damage the intestinal mucosa. The article reports the analysis of the intestinal biocenosis of piglets  with mycotoxicosis after the use of enterosorbents of mineral and organic origin (shungite from the Zazhoginsky deposit, the Republic of Karelia, zeolite from the Shatrashansky deposit, the Republic of Tatarstan, plant beta-glucans). Experimental research were carried out on 16 pigletsweaners of large white  breed of 70 days of age, divided into 4 equivalent groups. The animals were fed and monitored for 60 days.
The toxic food was obtained by introducing into the diet the mycotoxins: T-2 toxin (0,2 mg/kg), zearalenone (1 mg/kg), deoxynivalenol (0,5 mg/kg). Studies of intestinal microbiocenosis in animals with mycotoxicosis showed a decrease in the concentration of bifidobacteria and lactobacilli, an increase in yeast fungi, Escherichia coli, the appearance of Salmonella and Escherichia, which have hemolytic activity. 
The research provides that the correction of the intestinal biocenosis with enterosorbents contributed to the normalization of the intestinal biocenosis of  animals with mycotoxicosis. 

 The main condition for the intensification of animal husbandry is the acquisition of farms with highly productive animals. High milk productivity of cows is a predisposing factor for the development of metabolic disorders in their body. The search for possible solutions to the problem implies the additional introduction of biologically active substances, when choosing which one should give preference to those that are able to provide the symbiotic micronutrients of the proventriculus with the necessary micronutrients, since the effectiveness of all physiological functions and the  productivity of ruminants depend on its quantitative and qualitative composition. In our opinion, one of the promising directions for solving this problem is the use of feed additives containing plant extracts. The experiment was carried out in the conditions of the SPK "Kolkhoz named after Gorin", Belgorod region on black-and-white cows (Bessonov type). 
We have studied the effect of the use of the drug "Tanamin Zn" on highly productive cows 2 months before the expected calving on the indicators of  reproductive function. From pregnant cows during the start-up period, 2 groups (20 cows in each) were formed with analogues by origin, age, live weight, number of lactations and physiological state.
The cows of both groups were on the basic diet (RR). In addition, before and immediately after calving (twice a month), all animals were injected intraperitoneally with 10.0 ml of the complex vitamin preparation "Tetravit". The  results of the experiment indicate that the daily feeding of cows during the dry period of 20 g of tanamine Zn made it possible to improve the reproductive function of animals. This was reflected in accelerating the process of expulsion of the placenta by 13%, reducing the time for excretion of lochia by two days, reducing the number of cows with postpartum complications, reducing the indiffer- at the age of one month. 

 The research was carried out on the basis of a testing laboratory for monitoring the supply of food raw materials (poultry, pork, beef, sausage products) under state contracts in the period from 2016 to 2018. We evaluated the availability and correctness of veterinary accompanying  documents, labeling, identification characteristics, quality indicators in accordance with GOST for this type of product, safety indicators in accordance with the Technical Regulations of the Customs Union "On the  safety of meat and meat products" (TR CU 034/2013).
In total, in the period from 2016 to 2018, 94,317 tons of products were examined, from which 41,873 tons (44.4%) were rejected. As a result of the veterinary and sanitary examination, the specialists of the veterinary service withdrew products from circulation without veterinary accompanying  documents, or with violations in them. In addition, during acceptance, lots of  meat and meat products were rejected, which were received with non-compliance with the requirements for labeling. Violations of temperature  and humidity conditions, veterinary and sanitary conditions during the  transportation of chilled and frozen meat raw materials, as well as branding of meat were established. 
Among the rejected products, meat products that do not meet the requirements of the regulatory and technical documentation for quality and safety indicators were identified, in particular, Salmonella bacteria, Escherichia coli bacteria, and  high microbial contamination were found in meat and meat products. 
Thus, as a result of monitoring the supply of meat and meat products, the fact of falsification of products was established, as well as non-compliance with the requirements of technical regulations, which is a violation of the law and this product poses a threat to the health of the consumer. 

 The authors studied under experimental conditions the effect of disinfectants "Doctor Life-Dez", "Mirmekon 631 V", "Ecodesrico" for the sanitation of chicken incubation eggs. The studies were carried out on the basis of the scientific research consulting and diagnostic center for poultry  farming of the St. Petersburg State University of Veterinary Medicine  (SPbGUVM). For the study, an incubation egg obtained from a parent flock of Loman LSL-Classic hens was used. The incubation of eggs was carried out in a Russian-made incubator "Stimul IP-16 M" on the basis of the NKDC for poultry farming. As a result of the studies carried out, a high bactericidal activity of the preparations was established (according to the concentrations determined by the manufacturer of the preparation - 0.3% and 0.5%), but different harmlessness for developing embryos and hatched chickens. According to the results of the use of the disinfectant “Ecodesrico”, the residual toxicity of the preparation was revealed in the concentrations used (0.3% and 0.5% for the preparation) for developing chicken embryos. As a  result of inoculation and cultivation of washes taken from the shell surface of incubation eggs laid for incubation without preliminary disinfecting treatment, cultures of microorganisms of the infecting strain of  Pseudomonas aeruginosa were isolated, which were absent during the treatment of incubation eggs with the studied preparations. It was found that disinfectants significantly reduced the contamination of hatching eggs with microflora: in the experimental groups, the growth of single colonies of opportunistic microorganisms Bacillus and Staphylococcus was observed, but, in general, the samples remained sterile throughout the entire period of incubation. Thus, it was concluded that disinfecting the surface of the shell of hatching eggs with the used preparations ensures complete disinfection of eggs from pathogenic cultures of microorganisms and improves the quality of hatching of chickens. 

 Currently, increasing the efficiency of production in agriculture is the main task for scientists-developers of technological solutions, and quail farming  as one of the sub-branches of poultry farming is not exception. In most cases, producers solve this issue by increasing the safety of the livestock, using various preparations and feed additives, but also do not forget about the efficiency of the hatchery, since not only the quantity, but also the quality of young animals affects the future viability and productivity of individuals. Therefore, improving the efficiency of the hatchery is another mechanism for increasing the profitability of production. To optimize hatching and hatchability of eggs, transovarial processing of eggs before incubation with solutions of biostimulants (a solution of monoethanolamine, succinic acid, serine and pyridoxine hydrochloride) proved to be effective. This single treatment contributed to an increase in quail hatching and egg hatchability in both breeds of predominantly meat and egg production directions. In order to study the  effect of processing eggs with solutions of biostimulants on quail meat, a veterinary and sanitary examination was carried out (organoleptic assessment,  microbiological studies of the pectoral and femoral muscles, safety indicators), which proved that the meat of the control and experimental groups complies with the regulations, and can be used in food without restrictions, since the studied indicators were within the reference values. So, when studying the appearance, color, smell, pH, good quality, freshness of meat, reaction to peroxidase, determination of meat safety indicators (KMAFАnM, etc., antibiotics and pesticides), it was found that meat samples of all groups comply with the standards. In this case, the studies were carried out according to generally accepted methods. Thus, the use of biostimulants before the incubation of quail  eggs is not only an effective, but also a safe way to stimulate their embryogenesis and does not have a negative effect on the products obtained. 

 Food safety should be understood as the absence of danger to human  health when it is consumed. Duck meat has a high nutritional and biological  value, however, when eating poor-quality duck meat, there is a risk of food poisoning and toxic infection. In this regard, there are acute problems  associated with increasing responsibility for the effectiveness and objectivity of quality control of duck meat, which guarantees its safety for the health of the consumer. In this research work, duck carcasses with byproducts were  tested in terms of quality and safety. All studies were carried out in accordance with GOST 31990-2012 “Duck meat (carcasses and parts thereof). General technical conditions ". During the research, the following indicators were determined: the degree of exsanguination, the presence of  hypostases, fatness and the presence of pathological changes in organs and tissues; the presence of post-mortem changes in the meat, the appearance and color of the carcass surface, the color of adipose tissue, the condition of the serous membranes, the condition of the muscles in the cut, the consistency, the smell of the carcass, the transparency and aroma of the  broth; the amount of volatile fatty acids, primary protein breakdown products, ammonia and ammonium salts, acid and peroxide value of fat, peroxidase in meat, melting point of fat, pH of meat, content of proteins, fats and moisture in meat by conventional methods regulated by current regulatory documents. Compliance with the algorithm and an integrated approach in the implementation of veterinary and sanitary control when  handling duck meat allows us to provide the consumer with safe products. The studied samples of duck meat meet the requirements of the normative and technical documentation, in terms of organoleptic, physicochemical and  microscopic indicators and are recognized as benign. 

 Taking into account the increasing resistance of various microorganisms to antibiotics, including a wide range of new generations, the need for disinfectants will increase. In this regard, research is constantly underway to create a new concept of search and applications, environmentally friendly and costeffective biocidal drugs with a polyfunctional action (detergent,  degreasing and disinfectant) to ensure the biological safety of APK facilities, such comprehensive means can be used for high-level disinfection There are a bactericidal effect on dispute forms of microorganisms. Particular attention in disinfecting the premises of animals is paid to the development of disinfection regimes with such diseases as brucellosis included in the list of contagious, including particularly dangerous, animal diseases for which  restrictive measures can be established. The purpose of our research was the study of the bactericidal properties of the new drug in relation to various strains of Brucellian and dispute culture.
As a new drug, a composition representing a complex compound consisting of surface active substances and active ingredients (biocides) was used. The test crops were used by the reference strain B. аbortus 544 and epizootic strains of B. аbortus 2-15 and B. rangiferi 10441 allocated from disadvantaged in  brucellosis of farms. To evaluate the spore action, a free-dryed disputes of Вacillus cereus IP 5832.
The analysis of the results obtained, showed that both the reference and epizootic strains of B. aвortus have high sensitivity to a new complex biocide in comparison with other traditionally used drugs, also the presence of sporing properties at a lower concentration in comparison with the analogue. 

 This article discusses the influence of negative aeroions on the dynamics of the absolute liver mass of goose embryos. For determination of the degree  of aeroionization influence on the mass change of the embryonic liver, two batches of goose eggs were formed. During the entire incubation, air ionization sessions were carried out daily, lasting for 2 hours. The concentration of negative air ions was 17000 ions in 1 cm3. To achieve this goal - to determine the dynamics of the liver mass of goose embryos - 5 heads were selected from each group at 11, 13, 15, 17, 19, 23, 26 and 28 days of age. Liver weights were determined using an Adventurer AR-2140  balance. The egg of the first batch was incubated without aeroionization, and served as a control. The egg of the second batch was incubated using artificial aeroionization. To control the absolute weight of the embryonic liver, goose embryos were selected from both batches in 11, 13, 15, 17, 19, 23, 26, and 28 days of age. According to the results of the conducted  studies, it should be noted that negative aeroions had an affect on the liver mass of goose embryos. With the exception of 13 day old embryos, all the  studied age stages of embryonic development experienced greater liver mass when incubated using artificial aeroionization than the liver mass of embryos incubated without the use of aeroionization. At the same time, the greatest  difference in the liver mass of goose embryos incubated using aeroionization  compared with the embryos of the control group was recorded at 17, 19, and 23 days old. It should also be noted that by the end of embryogenesis (28 days) the difference in liver mass between the study groups was minimal. 

 At present, in a number of poultry farms, urate lithiasis (uric acid diathesis) is a frequent cause of the death of young animals, the development of which is stimulated by the stresses accompanying industrial incubation, as well as  the use of low-quality eggs, which leads to abnormalities in the development of the embryo, including its excretory system, causing a delay of uric acid in the body. This phenomenon is often aggravated by acidosis and a violation of the formation and functionality of thermoregulatory systems, which entails the production of nonviable young animals. The  paper considers a method for preventing these negative phenomena through the transovarial use of a composition of optimal concentrations of antioxidants – sodium thioctate and citric acid. According to the results of the studies, it was revealed that the presented composition has a positive  effect on the prevention of uric acid diathesis, which was expressed in a decrease in the intensity of lipoperoxidation, against the background of an increase in AOA in experimental chickens by 25,4%. This phenomenon was reflected in the intensity of the central metabolic processes, namely carbohydrate-energy and protein metabolism, which was reflected in the optimization of thermoregulation of experimental chickens. The  combination of the above phenomena resulted in the absence of cases of uric acid diathesis in experimental chickens, which was a consequence of the absence of acidosis in experimental chickens (reserve blood alkalinity was 10,8% higher in experimental chickens relative to the control), which is a central aspect  in the absence of this pathology. Thus, it can be argued that the composition of BAS presented by us actively levels free radical processes, which expresses the stimulation of the optimization of central metabolic processes and leads to the production of more highly viable young animals. 

 The aim of the study was to investigate the white blood cells morphology in female short-haired mink of the standard black breed in different periods of postnatal ontogenesis  with the existing technology of keeping and feeding. The experiment was carried out on repair females of the short-haired standard black mink (+/+), bred in the animal farm of JSC «Breeding animal  Farm «Saltykovsky» of the Moscow region. Blood samples for differential leukocyte count determination were taken in 10 females aged 4 months and 10 months, to monitor the physiological state of females in different periods  of minks’ postnatal ontogenesis. Blood was taken from the finger in the morning before feeding. Peripheral blood smears were stained using May-Grunwald method for leukocyte count determination. New data on age-related changes in the leukocyte count of female short-haired mink were obtained. A decrease of the  number of lymphocytes, eosinophils, monocytes (p<0,05) and an increase in neutrophils (p<0,001) in the blood correlated with the age of the females was found (at 4 months relative to 10 months), these changes have the similar trend as in longer hairline minks. A higher content of neutrophils 46,6-62,5% and eosinophils 3,9-7,2% was determined in comparison with dark brown (+/+) minks, which may be due to the genotypic features of black minks. The following indicators of productivity in the studied females were established:  Breeding performance was 5,63±0,64 puppies, young animals productivity on  the main female was 4,40±0,77 puppies. The obtained data characterize the physiological state of the animal organism in the adaptation process to the existing technology of keeping and feeding, and can be used for evaluation and research the impact of various factors that ensure the realization of genetic potential on minks’ organism. 

 Immunoglobulins are large glomerular proteins in blood plasma and are an important factor in humoral immunity. The concentration of  immunoglobulins in blood plasma directly characterizes the body's ability to protect itself from foreign agents. Immunoglobulins play an extremely  important role during pregnancy and lactation. Immunoglobulins of classes A, M and G enter the body of newborns with colostrum, thus realizing the biological mechanism of protecting newborns from infectious environmental influences. The shortage of immunological components of colostrum by young animals is associated with the widespread prevalence of mastitis in livestock complexes, since any form of mastitis adversely affects the  composition and sanitary and hygienic parameters of milk. 
This problem can be solved by local antigenic stimulation of the mammary  gland with various thermostable antigens corresponding to the main causative agents of mastitis. For example, the treatment of the mammary glands with staphylococcal vaccine a few days before giving birth allows not only to protect the lactating herd from mastitis of staphylococcal etiology, but also makes it possible to transfer anti-staphylococcal immunity to young animals in the process of drinking colostrum.
In our study, while continuing to study the physiological mechanisms of the implementation of the local immune response of the mammary gland, we wanted to record changes in the humoral factors of immunity upon local stimulation of the mammary gland with staphylococcal vaccine in an  experimental model of lactating mice.
The main purpose of this study was to com pare the concentration of immunoglobulins of classes A, M and G in blood plasma in lactating mice immunized with staphylococcal vaccine and individuals that were not immunized.
According to the results of the experiment, data were obtained showing that the concentration of immunoglobulins of all studied classes in immunized individuals significantly exceeds the concentration of the corresponding  immunoglobulins in mice of the control group. 

 The synoventricular system of the heart of farm animals is still not sufficiently studied and has fragmentary reports in veterinary practice. The functional significance of this system for the body plays a huge role in its life. Independent generation of a nerve impulse by atypical cardiomyocytes,  first of all, the sinoatrial node, as well as other links of the synoventricular system, provides automatism, consistency, and synchronicity of contractions of the heart muscle. The Anglo-Nubian breed is a unique breed of goat due to its high indicators of meat and dairy products. Due to the rather "wet" climate of the North-Western region of the Russian Federation, which is characterized by high humidity, cold temperatures and windiness,  AngloNubian goats often suffer from diseases of the respiratory and cardiovascular systems. The aim of our study is to study the histological features of the structure of the atrioventricular node of the AngloNubian goat. 
The study was conducted on the basis of the Department of Animal  Anatomy of the St. Petersburg State University of Veterinary Medicine. A total of 10  carcasses of Anglo-Nubian goats aged 12 months were examined. To achieve the obtained results, the following research methods were carried out: fine  anatomical preparation and production of histological preparations.
As a result of the study, it was found that the atrioventricular node in an Anglo- Nubian goat at the age of 12 months is located ventrally from the oval fossa next to the coronary sinus located in the atrial septum on the side of the right atrial cavity. The atrioventricular node consists of contractile cardiomyocytes, P  cells, and T cells. We established morphometric parameters of the area of the cells of the atrioventricular node, their thickness, as well as the size of the diameters of their nuclei. 

 The article presents the results of a retrospective study of magnetic resonance imaging of animals with histologically confirmed diagnoses of "osteosarcoma", "fibrosarcoma" and "metastatic carcinoma" in order to determine the features of visualization of these neoplasms. Due to good visualization of soft tissues, magnetic resonance imaging (MRI) allows to  accurately determine the localization of the pathology of the spinal cord and make a provisional diagnosis, in particular regarding neoplasms of the spinal cord, spinal column and paraspinal tissues. Despite the fact that the exact origin of the tumor can be determined only with the help of pathomorphological examination, on the basis of MRI it is possible to make an assumption whether it is an osteogenic tumor or soft tissue, due to certain criteria, such as the level of the signal from the tissue and the accumulation of contrast, which makes it possible to more accurately plan surgical intervention. 

 The ongoing metisation of Holstein cattle in Kholmogorskaya calls into question the continued existence of the breed and in the near future its gene pool will be lost, along with a number of adaptive and other economically useful qualities of these animals. Komi is one of the few regions where it was possible to preserve the population and breeding material of purebred and poorly holstinized Kholmogorsky cattle. Using data from breeding records in agricultural organizations of the Republic, a group of pure-bred and weakly holstinized (with a blood content of up to 25% for improving breed) Kholmogorsky cattle was identified (n=1034). In the selected animals, the immunogenetic method  was used to determine the  nature of alleles of the EAV locus of blood groups, the frequencies of which were compared with the results obtained by other authors for Kholmogorsky and Holstein cattle. It was found that the selected gene pool has B-alleles A'O'2, E'G'G", OY2I', O1Y2I', B'E'2G', G3OTA'2'2F'2K', Q, B1G1O1Y2, B1I2Y1G'G", Q'Q', G", O2, which are absent in the Holstein breed. The OA',  G", GIA', BOY, BO, P1, E'G'Q', BO3YA'E'3G'P'Q'G", BGKE'F"2O' alleles frequently found in Holstein cattle were not found in Kholmogorsky cows. Alleles Y2A'2, O2'J '2K'O', G'G", G2Y2D', common among Holsteins, were less common in the studied population. In the studied gene
pool, despite the greater number of EAV alleles, there is a more pronounced homozygosity (by 0.014), with a smaller number of effective alleles (by 2), compared to the results obtained for the Kholmogorsky breed in the 1980s. The selected group of cows highly preserved the pool of alleles characteristic of the ancestral Kholmogorsky population (r=0.834...0.863) and is of high value for supporting breeding and reproduction of the endangered breed. 

 With prolonged exposure to various stress factors, stress immunodeficiency occurs in the body of animals. At an early stage of stress, catecholamines intensively enter the bloodstream, contributing to the production of glycogenolysis and rapid mobilization of energy resources, while  simultaneously producing corticosteroids that suppress the activity of T- lymphocytes. In chronic stress, impaired functional and metabolic factors do  not have time to normalize due to the active secretion of catecholamines and corticosteroids, against this background, the number of all subpopulations of T-lymphocytes decreases and, accordingly, their  functional activity decreases, resulting in secondary immunodeficiency accompanied by the development of chronic pathological processes. As a  prevention of the development of stress, various pharmacological substances are used in animals, of which preparations of the group of adaptogens that increase the body's resistance to various adverse effects, regardless of their origin, are more widely used. The aim of the work is to study the reaction of the lymphocytic germ of hematopoiesis to the effects of cold stress and its correction with the probiotic drug "Intestevit "and the neuroleptic"Aminazine". The material for the research was clinically healthy mongrel white rats (females) selected by the method of analog pairs at the age of 11-12 months, kept in the same conditions in compliance with  adequate nutrition, temperature factors, light, humidity of the room. As a result, it was revealed that when using the probiotic drug "Intestevit" under acute stress, an active release of lymphocytes from the bone marrow is observed, followed by an activation of lymphocytic function by 11.9% under prolonged stress for further immune response. The use of the neuroleptic "Aminazine" during acute stress in the bone marrow leads to an increase in the number of lymphocytes, followed by a decrease indicating a weaker immune response. In animals that did not receive the drugs, the activity of lymphocytopoiesis also increases with acute stress, followed by its decrease with prolonged stress. 

 The scientific article provides information about the study of the features of blood supply, the state of the microcirculatory bed in clinically healthy newborn calves, as well as in the case of their dyspepsia. It was found that in clinically healthy newborn calves, the microcirculatory bed of the conjunctiva of the eyeball is represented by all the links of microcirculation, namely: parallel arterioles and venules that end in the corresponding capillaries, they form a cellular structure on the conjunctiva. In calves with dyspepsia, there are marked changes in the microcirculation of certain areas of the  conjunctiva of the eyeball. In this case, microcirculatory disorders are characterized by a change in the shape of the vessels, the unevenness of their caliber, the appearance of ampouleshaped extensions along the course  of the vessels, the appearance of constrictions in them. The ratio of the diameter of the venules of the diameter of the arterioles is 1:4, and in healthy calves this ratio is 1:2.
Intravascular changes are characterized by the appearance of aggregation of red blood cells (sludge phenomenon) in most vessels of the venular bed, as well as in capillaries and isolated cases in arterioles. Against the background of  pronounced disorders in the microcirculatory bed, and as is known, they reflect a systemic circulatory disorder, we conducted parallel studies of membrane digestion, using the example of protein hydrolysis. It was found that in sick  calves, there was a decrease in the enzymatic activity of glycyl-L-leucine dipeptidase along the proximal gradient. Thus, in calves with dyspepsia, there is a disorder of blood circulation in general and in the digestive system in  particular, which is a determining factor in the occurrence of disorders of membrane digestion, which performs the intermediate and final stages of hydrolysis of nutrients. 

 Many scientists have established the fact of the destructive effect of the accumulative and synergistic effect of mycotoxins on the body of young farm animals including poultry. Scientists from different countries are developing new and safe mycotoxins adsorbents. We have developed,  tested and patented feed mineral additives sorbents “MeKaSorb” and ‘Belasorb” based on tripoli. The purpose of our research was a comparative  analysis of the mycotoxin adsorbents action in different input rates during experimental work with mathematical modeling on broiler chickens of the  Ross-308 cross. The research work was carried out in the conditions of the VSAVM clinic and Applied Veterinary Medicine and Biotechnology Research Institute. Poultry in the main diet were given supplements in the norm of 0.5% -1.5% “MeKaSorb” + 1.5% -
2.5% “Belasorb”. Based on the conducted studies we found that the indices of all experimental groups were within the reference values. However, broiler chickens from experimental groups 2 and 4 had the best indices. In these groups there  was an increase in the level of total protein – by 1.2%, creatinine – by 4.5-4.6 % as well as triglycerides. Optimization of the Ca / P ratio confirms the positive effect of the addition of mycotoxin adsorbents MeKaSorb and Belasorb based on tripoli in the diets for poultry. During the research we noted the active behavior of the poultry which were not aggressive towards the service personnel. A positive effect was also noted when analyzing the broilers live weight reaching at the slaughter age. Based on the totality of the data received we will recommend the use of feed sorbents additives in the intensive industrial  production of poultry products. 

 The aim of the research was to study the morphometric parameters of the epithelial component of the breast of non-pregnant women, after childbirth and with mastitis in pigs. The research was conducted of the Stavropol Territory. The object of research was clinically healthy large white breed pigs of various functional states-non-pregnant, after childbirth and with signs of mastitis. All individuals were pigs of the corresponding species, 3 individuals  in each group. It was found that the area of ducts in the mammary gland in  pigs of a large white breed varies depending on their functional state. The minimum value of this indicator was in non-pregnant animals (293.00 µm2), after delivery, the area of the milk ducts increases by 5.45 times and reaches 1597.00 µm2. In mastitis, the average value of the area of the milk duct is significantly higher by 1.93 times (3081.00±651.00 µm2) compared with the data of animals after childbirth. In pigs after delivery, the average value of this indicator was 702.00±79.67 µm2, and with breast inflammation it was significantly less by 2.5 times and amounted to 281.80±65.23 µm2. In pigs, the variability of the parameters of the area of epithelial cells and the area of the nuclei of mammary epithelial cells was revealed, depending on the functional state of their body. In pigs after childbirth, the epithelial cell area increases by 2.34 times compared to non-pregnant animals, and in mastitis it is less by 35.36% than in females after childbirth, but higher by 1.51 times than in non-pregnant pigs. In postpartum pigs, the value of this parameter was significantly greater by 40.25%, and in mastitis, significantly less by 27.96% and did not differ from the data of non-pregnant animals. The average values of the nuclearcytoplasmic ratio in the epithelial cells of the non-lactating breast in pigs compared to the functioning healthy and functioning with injuries differ significantly. The minimum average value of the nuclear-cytoplasmic ratio of epithelial cells of the mammary ducts is observed in pigs after childbirth, the maximum - in non-pregnant pigs. In pigs, the average values of the area of galactocytes and their nuclei in mastitis are less than after childbirth. 

 Neglected dogs are part of society, they can be a source of zoonoses and zooanthroponoses. Knowing the pathological changes in the liver of neglected dogs living in urbanized areas, one can study the condition of the latter. Gastric and intestinal pathologies were observed in 87 % of the previously examined animals, pathologies of the kidneys in 57% and pancreatitis in 33% of those animals. The purpose of the study was to  analyze liver pathologies in neglected dogs living in the Altai Territory. The  object of the study was the liver and gallbladder of 41 neglected dogs of different sex and age groups, mongrels, which were supervised by animal welfare volunteers and animal protection organizations in the Altai Territory  in 2014-2021. The animals died for various reasons. The research methods were animal registration, postmortem  examination, statistical processing and analysis of the data obtained. As a result  of our studies, we didn’t find a relationship between gender and liver pathologies. In dogs, several changes were recorded in the liver at the same time. Pathological processes in the liver were observed  in 60 % of the studied  animals. The structure of pathological processes was as follows: 49% had dystrophic processes, 32% had cirrhosis, 20% had hepatitis, 15% had acute congestive hyperemia, 10% had neoplasms, 5% had toxic dystrophia. The peak of pathologies was noted at the age of 4 years (19%), 7 years (16 %), 5 years (14%). The main causes of pathological changes in the liver were high quality feeds, infectious diseases (distemper, piroplasmosis, infectious disease of unknown etiology), toxic substances, autointoxication, stress. 

 The aim of the research was to study the dynamics of the morphometric parameters of the thyroid gland of sheep in postnatal ontogenesis. The  studies were carried out in the Stavropol Territory. The object of the study was the thyroid gland of sheep of the Stavropol breed at the age of 1 day  (newborns), 3, 6, 9 and 12 months. All animals were females, three in each  group. As a result of studies, it was found that the area of the thyroid follicle in sheep of the Stavropol breed increases to six months, and then decreases to nine months. The maximum average value is observed at six months (2233.00 ± 502.30 µm2),  the minimum average value was observed in newborns (802.50 ± 72.88 µm2). The area of thyrocytes decreased with age, reaching a minimum mean value (19.75 ± 0.27 µm2) at six months. After the age of six months, this indicator increases. The maximum average value is observed in newborn sheep. The dynamics of the area of the thyrocyte nucleus is similar to the changes in the area of the thyroid follicles. At six months, the maximum average value (24.95 ± 0.86 µm2) of this indicator is observed, and by nine months it decreases, reaching a minimum at 12 months (18.07 ± 0.47 µm2). The nuclear-cytoplasmic ratio of the thyroid thyrocyte in sheep has similar changes in postnatal  ontogenesis. From birth to six months, there is an increase in the average value  of  the nuclear-cytoplasmic ratio and the achievement of a maximum (0.47 ± 0.008 ed). However, by the age of nine months, the indicator declines in sheep. At 12 months, the nuclear-cytoplasmic ratio becomes equal to that of newborn animals (0.36 ± 0.008 ed). 

 The article first studied the relationship immunogenetic characteristics of alleles for blood group sys tems D stallions with physiological levels of bacterial contamination of their sperm. For the first time it found that the system test stallions breeding blood groups have different effects on the level of contamination of the physiological sperm. The average for all 1676 obtained ejaculate total bacterial contamination of native sperm was  permissible level of 5000 CFU/cm3, and the number of E. coli was less than 800 CFU/cm3. We do not claim that the alleles of the blood group systems affect sperm contamination, but as a human blood group alleles systems of horses may contribute to contamination of various sperm due to the activity  of non-specific resistance of the animal organism. The greatest impact on the overall level of bacterial contamination of native sperm from stallions allele had blood group system D. The degree of influence of alleles blood  group system D is for the total bacterial contamination and the number of colony forming units of Escherichia coli respectively 22.9 % (p<0.01) and 10.7% (p<0.01). In the presence of the experimental stallions alleles blood  group system D ad/de, bcm/dk, cgm/de, cgm/dg, dg/cgm, dg/dk, dk/dk on average, there is a low total bacterial contamination of native sperm to 2000  CFU/cm3; when alleles ad/cgm, ad/d, ad/dk, bcm/d, cegm/d, cegm/dk, cgm/ceg, cgm/cgm, cgm/d, cgm/dk, de/cgm, de/dk, dk/d, dk/de - the average acceptable level of bacteria 2000-4000 CFU/cm3; contamination of native sperm from 4000 to 5000 CFU/cm3 was observed in the presence of horses alleles ad/bcm, dg/di, de/d, cegm/dg, bcm/cgm, bcm/de; in identifying the experimental stallions bcm/dg and cegm/cgm alleles blood group system D total bacterial contamination of native sperm was on average greater than the maximum permissible level of 5000 CFU/cm3.  

 Dog breeding in Russia is developing in different directions: service dog  breeding, decorative dog breeding, sled dog breeding, hunting dog  breeding and others. For the first time in Russia, the physiological characteristics of the native sperm of dogs of various breeds of domestic selection have been studied. The volume of ejaculate was the highest in males of the Rottweiler breed, which is 3.34 ml more (p<0.05) from the Labrador breed, 4.78 ml more (p<0.01) from male German Shepherd Dogs, by 1.34 ml more from Dobermans, 6.89 ml more (p<0.001) from Welsh Corgi, 12.68 ml more (p<0.001) from Pomeranians, and 12.54 ml more (p<0.001) from Yorkshire Terriers. The best sperm activity was observed by us in the German Shepherd, which is 1.11 points more than the Labrador breed, 0.66 points better than the Dobermans, 3.33 points more  (p<0.001) from the Rottweilers, 2.55 points more (p<0.001) from Husky males, 0.33 points more from Welsh Corgi, 2.22 points more (p<0.01) from Pomeranian and 1.77 points more (p<0.05) males Yorkshire Terrier breed. The concentration  of sperm was the highest in males of the Welsh Corgi breed, which is 17.78 million more from the Pomeranian, 38.38 million more from the Yorkshire  Terrier, 257.66 million more (p<0.001) from the Labrador, 173,11 million more (p<0.01) from the German Shepherd, 152 million more (p<0.01) from the Dobermans, 196.44 million more (p<0.001) from the Rottweilers and 253 million more (p<0.001) from Husky males. The smallest number of pathological forms of sperm was noted by us in Yorkshire terriers, which is 1.22% less from the Pomeranian, 1.11% less from the Welsh Corgi, 8.05% less (p<0.001) from the Husky, 5,5% less (p<0.001) from Rottweilers, 3.05% less (p<0.01) from  Dobermans, 1.78% less (p<0.05) from German Shepherd males and 4.05 % less (p<0.001) from Labrador males. 

 The article presents information on the normative morpho-microbiological indicators of the uterus of black-white Holstein cows, as well as in the subclinical form of endometritis. A complex of methods was used, including clinical examination of animals, anatomical preparation, microscopic morphometry, cytomorphological examination and statistical analysis of the obtained digital data. 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 in ZAO Povadino breeding plant. Cytomorphological studies were carried out on the basis of the Chance Bio laboratory. Objects of research - 20 black-white Holsteinized cows. 2 groups of animals were formed. Group 1 (n=13) - animals with endometritis, of which the acute form of the course (n=3), the latent form (n=10). 2nd group (n=7) - with no signs of this pathology, which is a morphological control. The formation of a group of animals with a normal course of the postpartum period was carried out on the basis of generally accepted methods, including examination of the external genital organs and rectal examinations. The data on the normative morphometric parameters of the uterus, which are basic in the differential diagnosis of its pathologies, are presented. Revealed micromorphological pathognomonic signs of subclinical endometritis. They are expressed in edema and infiltration of the endometrium, its sclerotic transformation, a decrease in the lumen of the uterine glands and their cystic degeneration. In the compared groups, the cytomorphological composition of the vaginal contents was established. In the control group, it was dominated (up to 60%) by surface epithelial cells. In case of subclinical endometritis, Staphilococcus aureus was revealed, Nonhemolytic Lac - fermenting Escherichia
coli and alpha hemolytic Streptococcus viridans group, which indicate the presence of an inflammatory process in the endometrium. The established morpho-microbiological correlations of the state of the uterus are basic in assessing the prognosis of the risk of development and the nature of the course of subclinical endometritis. 

 When handling meat, processing it with low temperatures is widely used - cooling and freezing. Processing meat with subzero temperatures leads to the formation of microscopic ice crystals inside muscle cells and in the  intercellular space, which disrupts the structure of muscle tissue and destroys individual myofibrils.
As a result of single and double defrosting of turkey meat, morphological changes in the structure of muscle tissue are observed. The integrity of  muscle fibers is impaired; in histological preparations of meat, their ruptures,
vacuolization, and thickening of myofibrils are found. As a result of histological studies of parts of turkey carcasses, it was found that the number of thickening of myofibrils in defrosted products is 4.79 ± 0.14, which is 1.86 times more than in chilled meat; in re-defrosted meat - 12.23 ± 0.51, 4.74 times more than in
chilled meat. The number of voids inside and between muscle fibers in  defrosted turkey meat is 3.03 ± 0.17, 2.66  times higher than the value in chilled, and 8.71 ± 0.38, 7.64 times more in redefrosted meat ... The number of muscle  fiber breaks in defrosted meat was 37.44 ± 1.07, which exceeds this value
for chilled products by 13.66 times; redefrosted - 57.69 ± 1.62, which is 21.05 times higher than in chilled products.
The obtained values are statistically significant - p <0.05. These microstructural changes affect the quality, technological and consumer properties of products, which increases the importance of identifying the thermal state of meat during its circulation. Acknowledgments: The reported study was funded by RFBR, project number 19-316-90022. 

 The article presents data on the dynamics of leukocyte parameters depending on the tension of the regulatory systems of the organism of  rabbits with a cellular content with a mesh floor. The research was carried out on the basis of the educational and scientific laboratory of rabbit breeding of the Belgorod State Agrarian University. The object of the study was silver rabbits aged from 5 to 8 months (n = 15). Counting the total number of leukocytes and leukocyte formula was carried out according to generally accepted methods. To establish changes in white blood, according to the classification of the adaptation process according to the degree of tension of the regulatory systems of the body proposed by Baevsky R.M., 1979, the ani mals were divided into groups: I - physiological norm, II - With  signs of tension of regulatory mechanisms, manifested by the presence on the plantar surfaces of the feet of the hind limbs of alopecia, white callus, hyperkeratosis; III - with signs of tension in regulatory mechanisms, characterized by the development of extensive alopecia on the plantar surface of the feet of the hind limbs and obvious hemorrhagic changes in the area of callus development.
Stage 1 of adaptation is characterized by the absence of any deviations from the normative values, the second stage of the adaptation process is  accompanied by changes in leukocyte indices and leukogram, characterizing a decrease in immune responses. The presence of hemorrhages in the area of alopecia and calcification of the supporting surface of the feet indicates the development of the third stage of the adaptation process, in which the factors of nonspecific resistance of the organism are activated and the development of autointoxication, as indicated by leukocyte indices and  leukoformula indicators. These changes lead to the development of a premorbid state. The search for markers of the development of homeostasis disorders allows taking into account the response to endogenous and exogenous factors, accordingly predicting the outcome of pathological processes and developing preventive measures.  

 Providing the population with good-quality and safe food products is one of the most important and priority tasks of the state. Food safety in a modern way presupposes not only the absence of harm to human health, but also such characteristics as the provision of reliable information about  the product to the consumer. One of the types of high-quality falsification is the distortion of information about the thermal state of raw meat and the replacement of chilled meat with frozen.
Assessment of the thermal state of meat during handling is carried out  organoleptically and histologically. The organoleptic method is quite subjective, the histological one - it allows with a certain accuracy to establish
the previous low-temperature treatment for destructive changes in the muscle tissue, however, it is difficult to perform in the conditions of the  circulation of raw meat. To control the quality of meat products, it is
necessary to find an effective and efficient method for assessing the thermal state of meat.
We have carried out studies of turkey meat to identify the thermal state by microscopy of native preparations. Microscopic examination of native  preparations of turkey meat, stained with hematoxylin-eosin, clearly shows striated muscle tissue, sarcoplasm stains pink, nuclei - purple, transverse  striation of fibers is observed. 
In native preparations from chilled poultry meat, muscle fibers are tightly arranged, unidirectional with respect to each other, the structure of the tissue is preserved. The ends of the muscle fibers are smooth, abrupt. In native preparations of defrosted and redefrosted meat, a violation of the  structure of muscle tissue was established, the fibers are arranged chaotically, with breaks and a violation of a single direction. In addition,  specific rounded thickenings were found at the ends of the muscle fibers, which are a clear identifying sign of defrosted meat and are absent in preparations made from chilled material. The easy reproducibility of the method of microscopy of native preparations makes it possible to use it as an express  method for operational monitoring of the thermal state of raw meat in the places of its processing, storage and sale while ensuring food safety.

 Up to 80% of slaughtered pigs have foci of pneumonia characteristic of non-specific bronchopneumonia [6, 7]. The incidence in individual farms can reach 100%, but the mortality rate, which is usually observed among suckling piglets, is insignificant. The main damage among the pig population consists of culling  of slaughter products and reducing weight gain.
The aim of our study was to study the state of cellular immunity in piglets with
nonspecific bronchopneumonia (determination of T-lymphocytes and their subpopulations).
The object of the study was piglets of different age groups. The piglets were kept in a large pigbreeding complex. 
The research was carried out at one of the large pig farms in the North-Western region of Russia and at the Department of Pathophysiology of the St.  Petersburg State Medical University. 
As a result of studies in all piglets with bronchopneumonia, we found a decrease in the total number and absolute value of Tlymphocytes and their  subpopulations (Thelpers and T-suppressors) in all age groups. 

 Progress in creating new forms of poultry is possible due to the rapid development of methods of cell and molecular biology. The creation of chimeric organisms is necessary to solve many problems of fundamental biology, to increase the population of endangered birds, or to restore extinct species and obtain transgenic organisms. The purpose of the work is the development and optimization of the technique for producing chimeras obtained from the Pantsirevskaya black, Kokhinhin karlikovy breeds and the study of their phenotype. 
The research material was, obtained from the «Genetic Collection of Rare and Endangered Breeds of Chickens» (VNIIRGZH Saint Petersburg).  Blastodisks were isolated from donors at the stage of freshly eggs (stage X according to Hamilton), which were crushed and cultured for two days at a temperature of 38°C in DMEM nutrient medium supplemented with 10% fetal bovine serum and gentamicin antibiotic. At the same time, the embryos of the recipients were cultured in the incubator, in which a small window was  cut out after two days. Using a micromanipulator, 5-7 μl of a suspension of donor cells was injected, they were glued with adhesive tape and placed in an incubator until the hatching stage.
To obtain chimeric organisms, 20 eggs were used as donors and 20 recipients for each breed. All were analyzed by the following indicators:  fertility, hatchability of recipients, and experiments on transplantation of blastoderm cells in order to obtain chimeras (Table 1). On average, 90% of  the eggs in the breeds studied were fertilized. The hatchability of experimental birds varied from 25% to 40%. The average number of chimeric organisms obtained by birds of two breeds was 8.3%.
With the selection options Kokhinhin - donor, Pantsirevskaya - the recipient  received chimera (Fig. 1) with unusual color. The ends of the feathers and   part of the head are bluish in color, obtained after transplantation of  cochinquin donor cells.
Two chimeras obtained after transplantation of blastoderm cells of an armored breed to cochinhin karlikovy recipients are shown in Fig. 2-3. In
Сochinchins with the gene for the weakening of the black color Bl (Blue), the black pigment turns into blue, so black spots on the beak and skin of
two experimental chickens are a sign of chimerism. 
Thus, by the method of transplantation of blastodermal cells isolated at the  stage of development X from one breed and transplantation into an embryo
of another breed, interbreed chimeras with a unique phenotype were obtained.