The article presents the results of a study of the immune response of chickens of the Dominant cross to vaccination with domestic and foreign vaccines against highly pathogenic avian influenza subtype H5N1. The following drugs were used as vaccines: Flu Protect H5, Reassortant Trivalent Vaccine (H5N6(H5Re13)+H5N8(H5Re14)+H7N9 (H7Re4)" and "Volvac® B.E.S.T. AI+ND". For quantitative analysis of the antigenic activity of vaccines in blood sera, ID Screen® Influenza H5 Indirect kits were used, designed to determine the titer of antibodies to hemagglutinin H5, and ID Screen® Influenza A Antibody Competition Multispecies, allowing to measure the titer of antibodies to NP protein (nucleoprotein of the influenza A virus). According to the results of the study, the Reassortant Trivalent Vaccine demonstrated the highest average antibody titer among the tested samples (10709.5), which indicates its high immunogenicity. The lowest efficiency indicators were shown by the vaccine "Volvac® B.E.S.T. AI+ND" with an average antibody titer of 2627.5. All three vaccines demonstrated high protective activity against influenza A virus of the H5N1 subtype, but the effectiveness and resistance of the immune response varied. A parallel study of blood sera using test kits focused on various influenza virus antigens (hemagglutinin and nucleoprotein) showed the possibility of differentiating an infected bird from a vaccinated one. This approach proved to be particularly effective in the use of subunit vaccines, allowing us to reliably distinguish natural infection from the vaccine immune response.

As the number of reports of antimicrobial resistance among various bacterial pathogens is increasing, there has been a revitalisation of research aimed at improving therapeutic measures associated with phage therapy. However, the fact that data on the effective use of phage-containing preparations are limited is of considerable concern, which, in turn, significantly hampers the active introduction of this alternative to antibiotics in the complex of anti-epizootic measures. In this regard, the aim of the study is to analyses the effectiveness of liquid commercial preparations of bacteriophages in assessing the lytic activity against Klebsiella pneumoniae isolated from calves with signs of bronchopneumonia, in vitro. Determination of phage particles was carried out by the conventional Gratia method (agar layers). The lytic activity of bacteriophages was evaluated by «spot-test» method. The analysis of our results demonstrates the possibility of potential application of commercial phage -containing preparations as part of the scheme of therapeutic measures in infectious bronchopneumonia of farm animals. Klebsiella pneumoniae strains isolated from nasopharyngeal mucus of calves showed sensitivity to bacteriophages included in commercial biopreparations used in the study. As the problem of growing antibiotic resistance among microorganisms is increasing, phage therapy becomes an attractive alternative.

Artificial intestinal media are in high demand in microbiological research in the field of veterinary medicine, since they allow obtaining a qualitative and quantitative composition of microbiota corresponding to the natural conditions. The only artificial intestinal medium currently available in domestic microbiological practice has not been validated and its use is limited to the cultivation of lactobacilli. In this regard, the development of a unified artificial intestinal medium (UAIM) that best matches the natural conditions of the intestine, using the example of Brown Nick chickens, is of scientific interest for the effective cultivation of microorganisms during microbiological research in veterinary medicine. In the course of the studies, existing artificial intestinal media were analyzed and key components were selected, including pectin, xylan, arabinogalactan, amylopectin, casein, starch, bactopeptone, salts and vitamins, which ensures the reproduction of natural intestinal conditions. To test the effectiveness of the medium, ten samples of chicken feces were selected, five of which were incubated under UAIM conditions, and the other five were cultured without the use of the medium. The resulting bacterial cultures were identified and quantitatively analyzed using MALDI-TOF mass spectrometry and the method of seeding on selective media. Statistical analysis showed no significant differences in the microbiota composition between the experimental groups (p>0.05), indicating that the intestinal conditions were successfully reproduced using UAIM. This study demonstrates the potential of UAIM for culturing intestinal microbiota and can serve as a basis for further studies aimed at modeling intestinal conditions in the development of veterinary drugs and feeds.

Brucellosis is a particularly dangerous infectious disease that causes enormous economic damage to livestock farms specializing in the breeding of cattle, sheep and pigs. Preservation of pathogens in a viable state with their original properties over a long period is one of the main tasks of the State collections of microorganisms. The aim of this paper was to study the reference strain Brucella canis RM 6/66, stored for more than 20 years in lyophilized form, determining its viability and investigating its biological properties and taxonomic affiliation. The obtained results are showed that the studied strain, when seeded on nutrient media corresponding to this species of pathogen, is viable. The study of its biological properties, using tests to determine dissociation, showed that the strain was dissociated, due to which a selection and cultivation of colonies according to White-Wilson. The pure culture of the strain of Brucеlla canis RM 6/66 in the R-form was obtained, (colonies are dark purple, with smooth edges and an uneven surface). The use of the RT-PCR identification method using species-specific primers and a TagMan probe showed that the strain B. canis RM 6/66 corresponds to the reference strain presented in international databases at all ten loci. 

Studies of Bacillus microorganisms open up broad opportunities for the use of probiotic strains in various fields of biotechnology. Bacillus microorganisms exhibit antiallergic and antioxidant effects, and produce antibacterial substances, bacteriocins and enzymes, which makes them promising for use as dietary supplements in agriculture and the food industry. Bacillus-based probiotics, especially in spore form, are resistant to aggressive conditions and are able to activate a nonspecific cellular immune response. In our study, we evaluated 5 cultures of Bacillus microorganisms for the development of probiotic drugs, with a focus on stimulating the humoral antigen response. The studies were conducted on Coturnix coturnix quails of the Texas breed (aged 14 days), the birds were divided into 5 experimental groups and 1 control (n = 7), as well as on ICR mice (CD1), which were divided into one experimental group and one control (n = 8). Antagonistic, hemolytic, galactosidase and DNase activities, as well as sensitivity to kanamycin, were studied. Immunogenicity and invasiveness of cultures were screened by evaluating sera in the immunofluorescence agglutination reaction. The length of intestinal villi in experimental animals was determined, and organs were weighed to determine mass coefficients. It was found that B. halotolerans strain No. 5.6 effectively lengthens intestinal villi in quails, but does not affect the mucous membrane in mice. Our studies confirmed that many B. subtilis strains are invasive, which is considered to be the main factor determining their immunostimulatory effects. This property is also useful for delivering vaccine antigens through mucous membranes, but the results showed that immunogenicity and the ability to overcome food tolerance in B. subtilis do not depend solely on invasiveness. Other Bacillus species, such as B. halotolerans, may hold promise for probiotic development.

Turkey breeding in the Russian Federation has a positive development trend, this is due to many useful qualities of meat. In addition to the positive aspects of the development of the turkey breeding industry, there are also negative ones, for example, as poultry farms in the turkey breeding sector develop and increase, the risks of infectious diseases increase, the most relevant for industrial turkey breeding is the prevention of dangerous diseases (OIE list) - Newcastle disease (NB), avian influenza (AI) and economically significant diseases of turkeys - hemorrhagic enteritis of turkeys (HE), infectious avian encephalomyelitis (AE), respiratory mycoplasmosis and mycoplasmic synovitis caused by Mycoplasma gallisepticum (MG) and Mycoplasma meleagridis (MM). The most common and economically dangerous disease is hemorrhagic enteritis of turkeys, unfortunately in the Russian Federation this disease is poorly studied. Therefore, it is necessary to direct research to the study of the biological properties of the virus, which will help to create diagnostic kits and means of specific prevention. That is why the purpose of our work is to study the biological properties of the HE virus. This set of studies includes: studying the concentration of the virus in target organs, macroscopic changes in organs, maternal immunity using the example of the half-life of antibodies to hemorrhagic enteritis. As a result of the conducted studies, data on macro and microscopic changes were obtained, the concentration of the virus was determined on various days after infection with RDP, and the halflife of maternal antibodies was determined. All these results will form the basis for the development of diagnostic tools and specific prevention in the future.

Metabarcoding research of the domestic animal intestines is relevant for veterinary medicine. The effect of feeding and food additives on its gut microbiome is of both applied and fundamental significance and demonstrates the stimulation of the various groups of bacteria development. The objective of our work is to study the effect of the domestic complete pet feed Dilly on the microbial community of the dogs’ intestines in breeding kennel of Irkutsk. The microbiome composition was determined in 12 animals of different ages having used Illumina MiSeq amplicon sequencing of the V3-V4 region of 16S rRNA. Rates diversity had been adapted to evaluate the affluence and prominence of Bacterial operational and taxonomic units and nonparametric Mann-Whitney criteria (correlative test, p≤0,05) used to evaluate the certainty value of the difference of operational and taxonomic unit percentage in different physiological groups. All in all, 147150 the 16S rRNA gene fragment sequences were obtained. The dominant bacteria turned out to be the phyla Firmicutes, Actinobacteriota, Bacteroidota, and Proteobacteria. The animals that had been under research had almost no Fusobacteriota bacteria - markers of a diet with a predominance of raw meat (predation). The Firmicutes phylum included bacteria from five families. The most numerous families among the Firmicutes were the Lactobacillaceae bacteria. Representatives of seven families were observed among Actinobacteriota bacteria, of which Bifidobacteriaceae predominated. Proteobacteria of the Enterobacterales order and Burkholderiales made up a small proportion of the entire community and depended on the animal age. The research result could be used in perspective to enlarge knowledge about the digestive process in an omnivorous animal of the wolf pack. These animals have a more or less flexible microbiome, which has several variants of normal composition. There predominated lactic acid bacteria in the microbial communities of the dogs’ intestines, which consumed feed that contained coarse dietary fibers. In its turn, lactic acid bacteria reduced the number of Fusobacteriota.

In the period from 1989 to 2022, bacteriological and helminthological studies of commercial marine and passing salmon fish of the northern Okhotsk Sea were carried out on the basis of the Magadan Scientific Research Institute of Agriculture in order to determine their infection with pathogens of important epizootological and epidemiological significance. Bacteriological research methods have established that a monoculture of virulent bacteria Aeromonas hydrophila has been isolated from the blood and parenchymal organs of pink salmon, chum salmon and coho salmon. 1772 cultures of microorganisms were isolated and identified with the determination of the virulence of aeromonads by the degree of DNA activity.When studying the helminthofauna, the objects of research were 4 species of marine fish in the amount of 3,621 specimens: herring, navaga, spiny flounder and toothed smelt, in which five pathogens of invasions Anisakis simplex, Pseudoterranova decipiens, Pyramicocephalus phocarum, Diphyllobothrium sobolevi, Corynosoma strumosum were registered.The highest rates were observed in Pacific herring - 97.4%, in navaga - 45.3%, smelt - 40.8%. Individuals with combined invasion have been identified: navaga A. simplex, P. phocarum, C. strumosum; flounder A. simplex (P. decipiens), C. strumosum; smelt A.simplex (P. decipiens), D. sobolevi, C. strumosum. In 59.8% of the navaga, plerocercoids of the diphyllobothriid P. phocarum were found. The infection of smelt with diphyllobothria D. sobolevi plerocercoids was 64.8%.During the study of spiny flounder, toothed smelt and navaga, acanthellae of the scraper Corynosoma strumosum were found, which were located on the internal organs and in the body cavity of fish. The total infection rate with this helminth over all the years of research was 98.9%, with an invasion intensity of 74.0.

Endometritis is one of the most frequently detected diseases of cattle, which is associated with disturbances in the microbial balance of the uterine cavity. This pathological process leads to disturbances in animal fertility, and, consequently, to economic losses in the dairy industry. In this regard, it is important to carry out timely preventive measures and have effective drugs for the treatment of postpartum endometritis. The aim of this study was to evaluate the effect of drugs based on bovine recombinant interferon "Biferon-B" and "EnrofloxacinferonB" on the taxonomic composition of bacteria in the uterine-vaginal discharge of patients with acute postpartum catarrhal endometritis of cows using high-throughput sequencing. It was found that the dominant species in the uterine cavity of cows with endometritis were Porphyromonas levii, Bacteroides heparinolyticus and Fusobacterium necrophorum. Bacterial taxa capable of causing various cattle diseases were detected in uterovaginal secretions. It was found that therapy of cows with the drug "Biferon-B" after 24 hours led to a tendency to increase the number of Caviibacter abscessus, Mycoplasmopsis californica and Histophilus somni. Statistically significant differences were found in the number of Porphyromonas SGB1983 before therapy (0.9%) and after therapy with "Enrofloxacinferon-B" during the first 24 hours (9.6%) (p<0.05). The study of the microbial diversity of utero-vaginal secretions of cows during therapy with "Enrofloxacinferon-B" on the seventh day established a tendency to decrease the relative abundance of bacteria Bacteroides heparinolyticus, Trueperella pyogenes and Mycoplasmopsis californica. The obtained data expand our understanding of the etiology of acute postpartum catarrhal endometritis in cows and the effect of drugs based on species-specific interferons on the course of this disease.

The article presents the results of studies evaluating the effect of the drug "Prostimul" on bone marrow hematopoiesis of piglets with perinatal hypotrophy. The experiment was conducted in a large pig farm, where newborn hypotrophic piglets were twice administered the drug "Prostimul" at a dose of 0.1 ml / kg of body weight on the 1st and 3rd days of life and changes in the bone marrow were evaluated. Background examination of the bone marrow in hypotrophic piglets showed the presence of erythroblasts and proerythrocytes and an increase in immature myeloid cells, which are an indicator of the initial stage of the inflammatory process. When analyzing the myelogram, the ratio of leukocytes to erythrocytes in normotrophic piglets turned out to be 1.4 times (p <0.05) higher than in hypotrophics, and the index of erythrocaryocyte maturation in hypotrophic piglets was 21.3% higher (p <0.05) than in normotrophic piglets. After using the drug "Prostimul", hypotrophic piglets on day 7 showed an increase in the number of polychromatophilic erythrocytes, a significant increase in the number of rodshaped and segmented neutrophils. The bone marrow index of neutrophils characterizing the activity of myelopoiesis in hypotrophic piglets after the use of the drug "Prostimul"was 8.8% higher than in normotrophic piglets. Two-time administration of the drug "Prostimul"to piglets with perinatal hypotrophy at a dose of 0.1 ml / kg of body weight had a positive effect on erythroid and myeloid sprouts, stimulating erythropoiesis and myelopoiesis. These changes indicate a positive effect of the drug on the compensatory mechanisms of hematopoiesis, which leads to an improvement in the overall health of piglets and a reduction in the risk of infections.

Fungal pathogens – dermatophytes are often the main cause of skin diseases in agricultural and domestic animals. These pathogens can cause superficial fungal infections – dermatophytosis. The market of veterinary drugs for the treatment of animals with dermatophytosis is represented by a wide range of antimycotic agents, however, treatment regimens using available drugs often become insufficiently effective, since dermatophytes infecting the skin become resistant to them. At the same time, certain pharmacological preparations, when ingested with food or as a result of external treatments, can negatively affect the physiological state of animals, in particular their reproductive function. The paper presents an assessment of the embryotoxic and teratogenic effects recorded in the antenatal and postnatal periods of development of the offspring of white rats with the external use of a new complex antimycotic agent against dermatophytosis of animals "Fungicor". It was found that the drug in the minimum (1500 mg / kg body weight) and maximum (15,000 mg / kg body weight) doses when applied to female white rats from the 1st to the 19th day of pregnancy did not have an adverse effect on the development of embryos and fetuses. There were no significant changes in the parameters of postnatal development of the offspring of the experimental groups in comparison with the control. Thus, the drug "Fungicor" does not have an embryotoxic and teratogenic effect.

The scientific article presents the results of studying the effect of the use of betaine in the form of a feed additive "Betacorm" on productivity, nonspecific resistance and peroxide oxidation in roosters of the CM 7 line of the "Shift 9" cross in conditions of limited feeding. Day-old progenitor chickens were selected and 2 groups (experimental and control) of 20 heads each were formed. The duration of the experiment was 38 days. The experimental group was included in the diet of the additive "Betacorm" of domestic production, containing 32% betaine, in the amount of 2 g / kg of feed from the age of ten days, gradually reducing the rate of daily feed intake. The chickens were raised in vivarium conditions in VIVIP. . On the 38th day of life, under conditions of limited feeding, in the experimental group receiving betaine, there was an increase in body weight by 5.6%, an average daily gain of 5.7%, as well as a decrease in feed conversion by 5.7%. The assessment of nonspecific resistance showed a tendency to improve the morphological composition of blood and an increase in the bactericidal activity of blood granulocytes by 15.3%. The use of betaine in the diet of chickens contributed to a significant decrease in the level of malondialdehyde by 15.5%. In the study of biochemical parameters of blood plasma (Table. 5) the chickens of the experimental group showed a tendency to increase the amount of total protein and albumin by 4.4% and 7.3%, calcium and phosphorus by 2.5% and 16.8%, as well as a decrease in the activity of aspartate aminotransferase by 3.6%. The results obtained indicate the beneficial effect of betaine in the diet on the health of chickens. An improvement in nonspecific resistance, an increase in productive indicators, bactericidal activity of granulocytes and biochemical parameters of blood were found.

One of the main tasks of modern animal husbandry is to provide favorable conditions for the maximum realization of the genetic potential of agricultural animals. Obviously, this is impossible without the introduction of various feed additives into the livestock diet. In this case, the environmental friendliness, safety and effectiveness of such additives play an important role. More than twenty years ago, many countries began to introduce restrictions on the use of feed antibiotics, up to and including a complete ban. In Russia, the possibility of adopting a legislative ban on the use of feed antibiotics is also currently being actively discussed. In this regard, there is a need to study alternative approaches to ensuring high productivity in animal husbandry. Natural feed additives of plant origin (phytobiotic additives) are a promising replacement for feed antibiotics. The search for sources was carried out in bibliographic databases, in scientific electronic libraries with search engines: Pubmed (https://pubmed.ncbi.nlm.nih.gov); Web of Science (http://www.webofscience.com); Elsevier (https://www.elsevier.com); Scopus (https://www.scopus. com); Springer (https://www.springer. com); Google Scholar (https://scholar.google.com); CNSHB (http://www.cnshb.ru). The Plant List database (http:// www.theplantlist.org) was used to provide scientific names and subspecies of plants.
The review presents data on the antibacterial, antiparasitic properties and biological activity of extracts and fractions of medicinal plants (climbing hops, stinging nettle, common yarrow, chamomile, common chamomile, St. John's wort, naked licorice), and also provides information on the experience of using these plants or their fractions as feed additives for farm animals.

The article presents analytical material on the study and application of plant materials as sources for the creation of phytobiotics and phytogenics for animal husbandry. Scientific articles in English and Russian with the keywords "phytogenics", "phytobiotics", "medicinal plants", "essential oil plants", "plants of the Omsk region" posted in bibliographic databases, in scientific electronic libraries of search engines were accepted as sources of literature. Publications of scientists of the Omsk region were studied in detail, on the basis of which it was established that more than 74 species of medicinal plants grow in the Omsk region, of which 30 have decorative, 27 honey, 17 medicinal and fodder values. The conducted analysis of scientific publications on potential sources of biologically active substances of plants growing in the Omsk region showed that the following wild plants are promising for the creation of phytogenics and phytobiotics: stinging nettle, calendula officinalis, yarrow, saltwort and oleaster angustifolia, the biologically active substances of which have a pleiotropic effect on the body, providing antibacterial, anti-inflammatory, hemostatic, immunomodulatory, antispasmodic, regenerating effects, as well as increasing the secretory activity of the glands of the stomach and intestines. The presented analysis of the chemical composition of saltwort samples growing in the Omsk region indicates the high nutritional value of plant materials and the need to study its effect on the functions of the animal body. A comparative analysis of the macroelement composition of halophyte showed that in June samples the content of magnesium, chlorine and nitrate anion prevails, while in samples collected in September the content of potassium, sodium, calcium and phosphates prevails, which must be taken into account when harvesting the plant.

The effect of drinking ciprofloxacin and enrofloxacin at a dose of 200 mg/l on phagocytosis of pseudoeosinophils in the blood of chickens was studied. Ciprofloxacin and enrofloxacin are antibacterial drugs of the fluoroquinolone group used in veterinary medicine. The most common use of these drugs in poultry farming is due to their excellent pharmacodynamic and antimicrobial properties. The aim of the work is to study the effect of fluoroquinolones on the phagocytosis of pseudoeosinophils. The study involved three groups consisting of day-old chickens of the Haysex Braun cross. Chickens of group I (control) received clean water, while in groups II and III ciprofloxacin and enrofloxacin were soldered for 10 days with water at a dose of 200 mg/l. Blood sampling was performed on the 1, 3, 5, 7 and 9 days after drug withdrawal. The phagocytic activity, phagocytic number, phagocytic index and phagocytic capacity of pseudoeosinophils were studied after co-incubation for 30 and 120 minutes with a culture of Staphylococcus aureus. As a result of the conducted studies of the effect of fluoroquinolones on the phagocytic reaction, no significant negative effects of the drugs were revealed. The main changes during incubation of pseudoeosinophils together with St. aureus were registered on the third and fifth days. Enrofloxacin caused shifts after 30-minute incubation with St. aureus, which manifested itself in a significant but not prolonged decrease in phagocytic activity, as well as an ambiguous short-term decrease followed by an increase in the phagocytic index and phagocytic number. All registered changes were short-lived.

Fish farming is one of the important branches of agriculture. Success in this area largely depends on the efficiency of feed use, which makes rational feeding of fish one of the most important aspects of their breeding. The purpose of this study was to investigate the changes in the morphofunctional state of the liver in common carp (Cyprinus carpio) after the inclusion of the probiotic “Bacell-M” in the fish diet. During the experiment, market-size carp weighing 800-900 grams were used. For baseline research, biological material was collected from common carp across all experimental groups for cytomorphological analysis. The fish were divided into two main groups. The first group (control, n=600) received a standard diet, while the second group (n=600) was fed the same diet supplemented with the probiotic Bacell-M at a dose of 2 kg/ton for 30 days. Slaughter and biological sampling for all groups (n=6) were performed at two time points: 14 days and 35 days after the start of the experiment.
The results of the study demonstrated that the probiotic exerted positive effects, such as supporting the integrity of the liver's vascular and parenchymal structures, reducing lipid accumulation in hepatocytes, decreasing inflammatory infiltrates, and maintaining microcirculation within the liver. To assess these effects, we measured the expression of the GPx-1 gene, which plays a key role in cellular defense against oxidative stress.

Impaired fertility in cattle is the cause of economic losses in livestock farms. Complex treatment of cows with acute endometritis may include various approaches, including the use of antibiotics and interferon-based drugs. The therapeutic approach associated with the use of immunostimulating substances is the safest. The aim of the study was to evaluate the blood parameters of cows during the treatment of acute postpartum catarrhal endometritis using «Enrofloxacinferon-B» and «GentabiferonB». It was found that therapy with «Enrofloxacinferon-B», «Gentabiferon-B», and the traditional treatment regimen led to an increase in phagocytic activity, which was probably due to the activation of the immune system of animals. At the same time, during therapy with «Enrofloxacinferon-B», a decrease in catalase activity was observed, which may be due to a decrease in the level of active oxygen forms in the blood of animals during therapy with this drug. It was also noted that during the therapy with «Enrofloxacinferon-B» no changes in the level of the circulating immune complexes were observed, while with the traditional treatment regimen an increase in this indicator was observed. Therapy with «Enrofloxacinferon-B» did not lead to an increase in neutrophils. At the same time, both the traditional treatment regimen and therapy with «Gentabiferon-B» led to an increase in the proportion of neutrophils. It is noteworthy that there was no pronounced negative effect on blood parameters of all three endometritis treatment options. It can be assumed that the most optimal treatment regimen for acute postpartum catarrhal endometritis in cows may be therapy including «Enrofloxacinferon-B» at a dose of 20 ml at intervals of 24 hours for 5 days.

In the etiology of mastitis, pathogenic bacteria Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Corynebacterium bovis and a number of others are of paramount importance. Frequent unjustified use of antibacterial drugs without prior determination of effectiveness against microorganisms in a particular farm led to the formation of resistant isolates. The aim of the research was to study the sensitivity of bacterial strains isolated from cows with mastitis to the antibacterial drugs MASTIBLOCK® DC 49, MASTICAN-P and MASTIGARD. The research was carried out in a large dairy complex in the Central district of the Russian Federation. The experimental groups included cows with clinical signs (No. 1) and subclinical form (No. 2) of mastitis with positive results of studies using the KENOTEST reagent. Antibiotic sensitivity of bacterial isolates isolated from milk was determined by the cylinder method. In cows with a subclinical and clinically pronounced form of mastitis, Staphylococcus aureus, Corynebacterium spp., Streptococcus agalactiae, Bacillus spp. (β-hemolytic isolates) were isolated during bacteriological examination. The maximum effectiveness of MASTIBLOCK® DC 49 has been established in the subclinical serous-catarrhal form of mastitis, mainly against Grampositive bacteria. MASTIGARD has a wider range of antimicrobial effects, including on strains producing β-lactamase and inhibiting the action of penicillin antibiotics. The results obtained allow us to recommend the use of the complex antibiotic MASTIBLOCK® DC 49 not only during the dry season, but also during lactation to stop bacterial infection of the breast in cows, while observing the appropriate technology of milking and milk processing.

The positive effect of microelement chelates compounds in Bioferron and Biocink on the composition of essential acids in quail meat raw materials has been substantiated. The experiment used quail of the Japanese breed, egg-meat direction in the amount of 280 heads. The highest level of essential amino acids in meat raw materials was noted in quails of 37-day age. The highest level of arginine was noted in the sixth experimental group (Biocink 0,3 ml/kg) – 5,25 ± 0,27% (p≤0,01), which is 0,92% higher than in the control group. The highest level of valine was noted in the group in whose diet Bioferron was included at a dose of 0,2 ml/kg, it was 3,30±0,19% (p≤0.01), which is 0,79% higher than in the control group. The histidine level exceeded the control level by 0,25 -0,40% (p≤0,05). Leucine and isoleucine have the highest levels of all amino acids in quail meat raw materials. In the meat raw materials of quail of 37 days of age among the experimental groups receiving Bioferron, the highest level of leucine and isoleucine was noted at a dose of 0,2 ml/kg – 13,17 ± 0,49% (p≤0,001), which is 3,86% more than in the control. Among the experimental groups treated with Biocink, the highest level of leucine and isoleucine was noted at a dose of 0,2 ml/kg – 12,45±0,54% (p≤0,01), which is 3,14% more than in the control. The content of methionine in meat raw materials of 37-day quail, in the diet of which Bioferron was present at doses of 0,1, 0,2 and 0,3 ml/kg, was 1,57±0,10, 1,75±0,11 and 1,74±0,11% at p≤0,01, which is 0,28, 0,46 and 0,45% higher than the control, respectively. In the quail groups treated with Biocink 0,1, 0,2 and 0,3 mL/kg, methionine levels were 1,47±0,07, 1,70±0,11 (p≤0,01) and 1,69±0,12 (p≤0,05), which is 0,18, 0,41 and 0,40% higher than the control, respectively. In the Bioferron 0,1, 0,2 and 0,3 mL/ kg inclusion groups, tryptophan levels were 0,21, 0,67 (p≤0,05) and 0,65% (p≤0,01) higher, respectively. Tryptophan levels were 0,16, 0,66 (p≤0,05), and 0,64% (p≤0,01) higher in the Biocink 0,1, 0,2, and 0,3 mL/kg inclusion groups, respectively. The highest level of phenylalanine was noted in the second experimental group (Bioferron 0,2 ml/ kg) – 3,87±0,25% (p≤0.01), which is 1,13% higher than in the control group.

Correlation analysis is an important tool in veterinary medicine, since it allows us to study the relationships between various indicators of animal health and the results of diagnostic tests, which allows us to confirm or reject the relevance of various biomedical hypotheses. The relevance of this method is due to the need to confirm the reliability of diagnostic models, which, in turn, helps to improve the accuracy of disease diagnosis, as well as the introduction of new similar methods with high prognostic value. Veterinary practice requires a high degree of reliability in the results, since incorrect diagnosis can lead to serious consequences for the health of animals. The pharmacokinetic parameters of caffeine in clinically healthy laboratory animals and cattle were used as material for the study. Correlation relationships between caffeine concentration (for equivalent time intervals), total plasma clearance, average residence time of the substance, and distribution volume were analyzed. For a complete analysis, parametric (Pearson correlation coefficient) and nonparametric (Spearman rank correlation coefficient) correlation indicators were used. The correlation coefficients we used to analyze relationships in pharmacokinetic studies show ambiguous results when comparing exogenous caffeine in two animal species. Despite the presence of similar correlation features, stable relationships were not established, which indicates the complexity of interactions and individual interspecies characteristics. In addition, differences in responses between males and females also do not show pronounced stability, which may be due to differences in metabolism and physiological characteristics. Thus, future studies should include the study of pharmacokinetic parameters in other animal species to provide more accurate predictions and improve understanding of metabolic processes associated with caffeine. This will allow the creation of reliable and universal methods for assessing the state of the hepatobiliary system in various animals.

In the context of studying clearance methods for assessing exogenous substances as a diagnostic indicator of the state of the hepatobiliary system, the researchers did not come to an unambiguous conclusion about which of the clearance indicators is the most relevant, so this issue requires further study. The main objective of this study is to identify the main indicators of renal clearance in clinically healthy productive animals (cattle) and to assess the relevance of these indicators in comparison with the data obtained in the previous experiment on assessing plasma clearance. The studies were conducted in 2024 in one of the livestock farms of the Pskov region of the dairy industry, Holsteinized cattle were used in the experiments, average productivity is up to 5.5 thousand milk per year, age is 1 ± 0.2 years. The experimental animals were given a single injection of an isotonic solution of caffeine sodium benzoate (OOO Mosagrogen, Russia) at a dosage of 5 mg/kg, since this dosage is the safest in toxicological terms and the most representative in clinical terms. After 1, 2, 3, 4, 5, 6, 8, 10, 12, 18 and 24 hours, urine was collected from the experimental animals by massaging the bladder [9], after which the caffeine levels were determined by the enzyme immunoassay method using the ELISA-Caffeine test system (manufacturer Gold Standard Diagnostics, USA) on a Stat Fax 4700 strip ELISA analyzer (USA). The results obtained were compared with the concentration of caffeine in blood plasma from the previous series of experiments by determining the correlation coefficient using the methods for calculating the Pearson, Spearman, and Fechner correlation coefficients. Renal and plasma clearance indices have a direct moderate relationship, which is confirmed by all methods of measuring the correlation coefficient. This relationship emphasizes the importance of the functional state of the kidneys for the systemic metabolism and pharmacokinetics of exogenous substances, as well as the possibility of applicability of this diagnostic model in practice.

Hepatic elimination is a function of interactions between various processes, such as sinusoidal absorption, intracellular metabolism, canalicular (biliary) secretion and sinusoidal outflow. The aim of our study was to investigate the relationship between the clinical condition of cattle with a confirmed diagnosis of fatty hepatosis and the metabolism of sodium caffeine benzoate. The studies were conducted on a farm in the Pskov region; the object of the study was Holsteinized cows, which underwent a medical examination, according to the results of which animals with fatty hepatosis were selected. The experimental animals were injected once with a sterile solution of sodium caffeine benzoate (OOO Mosagrogen, Russia) at a dosage of 5 mg / kg (according to the instructions and previously developed methods). The control group, healthy animals, were injected with the same drug in a similar dosage. After 1, 2, 3, 4, 5, 6, 8, 10, 12, 18 and 24 hours, blood was collected from the experimental animals by venipuncture of the jugular vein, after which caffeine levels were determined by the enzyme immunoassay method using the ELISA-Caffeine test system (manufacturer Gold Standard Diagnostics, USA) on a Stat Fax 4700 strip ELISA analyzer (USA). The correlation model for diagnosing hepatobiliary pathologies based on caffeine clearance was studied by identifying correlation coefficients (Spearman and Pearson). With normal liver function, caffeine is eliminated within the expected time frame, but in the presence of pathologies, a delay ("plateau") in the elimination of the substance is observed. Based on the analysis of the data obtained, it is possible to create prognostic models that allow veterinary specialists not only to diagnose, but also to form an idea of the course of diseases.

The addition of melamine and urea to milk helps to increase the protein content, which is one of the main criteria for evaluating its quality. This is due to the fact that the determination of protein is directly related to its calculation by the non-protein and protein nitrogen determined by the Kjedal method, and melamine and urea contain nitrogen molecules in their composition. An interesting question is the effect of these adulterating components on milk quality indicators. The main method for determining these indicators is ultrasonic, implemented using milk analyzers. However, they do not provide for the determination of melamine and urea, which are determined by high-performance liquid chromatography and colorimetric methods, respectively. Therefore, it is not possible to detect the adulteration of milk with melamine and urea using ultrasonic analyzers. The aim of the work was to determine the effect of melamine and urea when added to milk quality indicators determined using an ultrasonic analyzer "Lactane 1-4". The work was carried out in stages on the basis of the educational and research center for the examination of food and animal Feed of the St. Petersburg State University of Veterinary Medicine. The objects for research were samples of raw milk with different concentrations of melamine and urea. Thus, the dependence of milk quality indicators on the concentration of urea and melamine in it has been established. At the same time, it was found that the higher the concentration of these substances in milk, the higher the value of its indicators such as mass fractions of protein, fat and density.

The objective of this study is to assess the efficacy of a combination of phytobiotic (Quercus cortex) and probiotic preparations (lactobifadol) as feed additives in the growth of broiler chickens. The studies were conducted in accordance with accepted zootechnical methods in poultry farming, under controlled conditions in a vivarium and the Center for Collective Use FRC BST RAS (Orenburg, Russia). The scientific novelty of this study lies in the fact that the primary factor contributing to the enhancement of poultry productivity and the production of quality products is the exclusion of antibacterial drugs from the feed ration. The use of these substances can result in both beneficial and adverse effects. For instance, they may cause toxic or allergic reactions, and the ingestion of antibiotic residues through the consumption of broiler meat is also a possibility. Currently, there is a great deal of scientific and practical interest in the identification and study of alternative feed additives, as well as their combined effects. The results demonstrated that animals receiving supplements consumed less feed and exhibited higher growth rates compared to the control group. The live weight gains of chickens receiving Quercus cortex extract and lactobifidol separately increased by 9.54 and 6.75%, respectively, while feed consumption decreased by 5.68 and 7.01%, respectively. The maximum reliable gain in live weight of broilers (16.9% (p≤0.01)) was observed on the background of combined feeding of Quercus cortex extract and lactobifadol, on the background of reduced feed consumption by 5.68 and 7.01%, respectively.

Promising methods of laboratory analysis, including the determination of the content of various substances in food products, include near- and medium-range infrared spectrometry, which allows the identification of chemical compounds. The method of IR spectrometry in the medium range is of the greatest scientific and practical interest, namely its application as an express analysis for the quantitative determination of the content of chemicals. There are few works in the scientific literature on the construction of calibration characteristics for IR-Fourier spectrometers in order to assess the safety parameters of milk, including melamine content. The aim of the work was to construct a calibration dependence for estimating the melamine content in milk using IR-Fourier spectrometers. The research was carried out in stages on the basis of the educational and research Center for the examination of Food and Animal Feed of the St. Petersburg State University of Veterinary Medicine. A standard sample of melamine, samples of raw milk without melamine and with melamine in various concentrations determined by high -performance liquid chromatography were used as materials for research. Based on the results obtained, a model of calibration dependence was built, which makes it possible to determine the quantitative content of melamine in milk at its pressure in order to falsify protein. The use of such models will allow not only the identification of chemicals, but also to determine their quantity, which is a promising direction in the development of new methods of physico-chemical analysis of food products and raw materials.

One of the common disorders in highly productive animals is nutritional osteodystrophy, which leads to significant economic losses. Most often, a violation of mineral metabolism is observed in highly productive cows during lactation, when their last caudal vertebrae soften or completely disappear. To achieve the best physiological parameters of Jersey dairy cows, we were tasked with studying the practical significance of using the Monocalcium Phosphate feed additive in the treatment of nutritional osteodystrophy in Jersey cows in industrial livestock farming conditions. The purpose of the research work was to establish the effect of the feed additive “Monocalcium phosphate” in the treatment of nutritional osteodystrophy in cattle. We formed two groups of animals, according to the principle of analogous pairs in age and live weight (n=75). The control group was fed according to the diet generally accepted on the farm. In the experimental group, “Monocalcium phosphate” was administered with animal feed for 30 days at a rate of 100 g/animal. daily. During the first five days, the dose was gradually increased. On the first day, the additive was introduced at the rate of 10 g/ bird, on the second day – 20 g/bird, on the third – 40 g/bird, on the fourth – 60 g/bird, and then 80 g/bird. once. The duration of observations was 30 days. Blood for analysis was taken from the saphenous vein in the neck in the morning, before feeding the animals. The results of the experiment showed that the inclusion of monocalcium phosphate in the diet of animals had a positive effect on the clinical composition of the blood. In particular, in the experimental group the level of hemoglobin increased by 3.2%, total protein - by 6.2%, reserve alkalinity - by 10.1%, Ca - by 2.56% and P - by 17.07% at optimizing the ratio of microelements. Thus, based on the research conducted, it has been established that that the use of “Monocalcium phosphate” in the diets of dairy herds helps to improve metabolic processes in the body of animals, normalize mineral metabolism, and, consequently, prevent nutritional osteodystrophy.

The article presents the results of biological effect of iron nanocomposite on growth and hematological parameters of broiler chickens cross “Arbor Acres”. The research was carried out in the conditions of the Department of Biotechnology of Animal Raw Materials and Aquaculture of the Federal State Budgetary Institution of Higher Education "Orenburg State University" and the Federal State Budgetary Scientific Institution "Federal Scientific Center of Biological Systems and Agrotechnologies of the Russian Academy of Sciences". The aim of the research is to evaluate the biological effect of the Fe-C nanocomposite on growth, morphological parameters of the blood of broiler chickens.Experimental groups as a feed additive during the accounting period received iron nanocomposite in dosages: 0.2 ppm, 0.4 ppm and 0.8 ppm. The positive effect of FeC nanocomposite on growth and hematological parameters of young carp when included in the diet was established. The increase in the content and concentration of hemoglobin in erythrocytes, the number of eosinophils in all experimental groups, neutrophils - in the second and third groups, lymphocytes - in the first group relative to control values, as well as an increase in the number of platelets in the first and third groups. The best result in terms of growth dynamics and hematological parameters was obtained in the experimental group, in which 0.2 ppm iron nanocomposite was additionally added to the main diet.

In this study, using the original neural network information technology, it was possible to perform an intelligent analysis of molecular genetic data of silage microflora and evaluate the influence of silage starters and preservatives on the directionality of microbiological biochemical processes in silage biomass. The output product of the intelligent analysis of fractal profiles of silage microflora was the CSIgaZ and CSImU indices, chosen to represent quantitatively, in terms of microbiological data, the intensity of silage outgassing and the amount of lactic and acetic acids in silage. According to the CSImU index it was possible to evaluate the increase of lactic acid and decrease of acetic acid in silage, which signals the slowing down of development of putrefactive microorganisms in silage, and according to the CSIgaZ index - the decrease of silage gas emissions, which indicates favourable anaerobic conditions in which microbiological biochemical processes in silage take place. The laboratory experiment on silage of hedgehog silage conducted in the molecular genetic laboratory of ‘Biotrof’ Ltd. showed that ‘Biotrof-111’ (based on Bacillus subtilis, produced by ‘Biotrof’ Ltd.) creates the best anaerobic conditions in the silaged plant biomass, where the microflora of silage bioconsolidates in the biosystem of lactic acid bacteria. LLC ‘Biotrof’) creates the best anaerobic conditions in the silage plant biomass, in which the silage microflora bioconsolidates into a biosystem of lactic acid bacteria with a minimum value of CSIgaZ index = 3.1 and a maximum value of CSImU index = 6.8, that is, in this variant of silage silage hedgehog silage microflora of silage manages to group in such a way, that simultaneously provides a relatively low intensity of silage gas emissions, accelerated formation of lactic acid and slow formation of acetic acid in silage, and thus in these conditions the processes will be completed with the best quality nutritional indicators of silage.

Currently, the current method of correction and maintenance of the balance of intestinal microflora of birds is the use of probiotics - biopreparations created on the basis of live microbial cultures. Of particular interest for the prevention of gastrointestinal diseases of birds are probiotics based on lactobacilli with high antagonistic ability, which determines their practical application in poultry farming. The introduction of probiotics into the diet of birds from the first days of life stabilizes the microflora of the gastrointestinal tract and improves physiological processes, which contributes to increased safety and increased productivity of birds. The article presents data from a comparative study of the antagonistic activity of the probiotic biocomplex "AVIBIOLAKT" and individual cultures of lactobacilli included in this biopreparation - Lactobacillus acidophilus, Lactococcus lactis, Lactococcus cremoris. Isolates of pathogenic and opportunistic microorganisms from the collection of the Museum of Working Cultures of the Bacteriology Department of the All-Russian Research Institute of Vitiligo and Infectious Diseases were used as test cultures: Escherichia coli, Salmonella enteritidis, Staphylococcus aureus, Pseudomonas aeruginosa. The present studies have confirmed the antagonistic efficiency of the biocomplex "AVIBIOLAKT" in relation to opportunistic and pathogenic test microorganisms. The probiotic biocomplex "AVIBIOLAKT" had the highest antagonistic activity in relation to test microorganisms. It formed a growth inhibition zone from 16.4 to 19.6 mm depending on the test strain. Thus, the growth inhibition zone of Staphylococcus aureus was 19.6 mm, Escherichia coli and Salmonella enteritidis - 19.3 and 18.8 mm, respectively, and Pseudomonas aeruginosa - 16.1 mm. It was established that the level of antimicrobial activity against test microorganisms - Escherichia coli, Salmonella enteritidis, Staphylococcus aureus, Pseudomonas aeruginosa. was expressed to a greater extent in the biocomplex "AVIBIOLAKT". In individual cultures of lactobacilli of the studied probiotic biocomplex, the antagonistic ability was less pronounced. Lactobacillus acidophilus had the greatest antagonistic activity among individual cultures of lactobacilli.

The article describes the application of thin-layer chromatography method for the detection of synthetic pyrethroids in hen's eggs obtained in poultry farm egg production facilities located in the Leningrad region after insecticidal treatment with 1% s-biotrin solution. Chromatography was carried out according to the adapted methodology with the use of UVK-HDi ultraviolet cabinet, the company “Petrolaser” Ltd. Sample preparation was based on the analysis of literature sources and the experience of the experiments conducted earlier. For this purpose, the egg contents were homogenized and subjected to extraction with the addition of organic solvent acetone. The obtained extract was centrifuged at 1000 rpm. The precipitate was dehydrated in a desiccator until the lowest mass was reached. No pesticide content was detected in chicken egg samples collected from the insecticide treated poultry house. The results were consistent with those of samples from a control poultry house that had not been treated. The chromatography results of chicken egg samples from production facilities were compared with the results of eggs experimentally treated with a 1% insecticide solution. Solutions of the active substance at the same concentration were used as a control to evaluate the chromatography results. Substance stains on the plates corresponded to the values of pure substance solution samples. The mobility coefficient of s-biotrin was 0.31±0.03. The method of thinlayer chromatography is an accessible and indicative method of qualitative analysis of the content of residual concentrations of synthetic pyrethroids and disinsection efficiency. The use of modern equipment and materials of domestic production makes this method available for laboratories and research organizations of various levels, which demonstrates the relevance of the development of this technique in the context of the need for import substitution.

In conditions of intensive chemicalization of agriculture, cases of contamination of agricultural products with residual amounts of pesticides and veterinary drugs are increasing. A significant role among them is played by organophosphorus compounds, which, despite the relatively low danger to the body, are capable of accumulating in the fatty tissue of animals, which poses a threat to human health. Due to the wide variety of chemical groups of the substances used, differences in their physicochemical properties, method of application and environmental conditions, it is often difficult to accurately identify contaminants. Organoleptic, physicochemical indicators, as well as mobility coefficients of residual amounts of diazinon and chlorophos were determined by TLC, using UFK 254/365 - HD. At the same time, there was no change in organoleptic and physicochemical indicators in the test samples, which does not allow us to establish contamination of the products. During chromatography, residual amounts of organophosphorus compounds were detected, mobility coefficients Rf of diazinon were determined to be 0.65±0.01 and chlorophos to be 0.19±0.01, which corresponds to the value of control solutions. The use of available components and domestic equipment, as well as the possibility of parallel determination of a large number of samples, allows this method to be used as a screening method to ensure food security.

Poultry farming is one of the most dynamically developing branches of agriculture in Russia. To ensure high productivity of poultry and improve product quality, poultry farmers use various feed additives. However, now, due to the difficult situation in the country and many sanctions imposed, the offers on the domestic feed additives market may cause difficulties in choosing the best option. In this regard, the purpose of this article was to analyze feed additives with components of plant origin that exist in our country and are used in poultry farming (as of 2023). An analysis of literary data, data from the state register of feed additives produced on the Russian market made it possible to assess the situation in the field of feeding agricultural poultry. The supply and demand for these additives were studied, and research data on various types of additives with plant components on the body of agricultural poultry are provided. It should be noted that more and more attention in the modern production of feed antibiotics for farm animals and poultry is paid to the use of components of plant origin, the so-called phytobiotics. The article provides solutions to the problem and development prospects for the domestic feed additives market, and also indicates the potential for improving the quality and diversity of supply. It is concluded that the analysis is important for feed additives manufacturers, as well as specialists and researchers in the field of poultry farming.

Many factors influence the milk productivity of cows. One of such factors is the technology of feeding animals, the element of which is the feed table and its coating. The article provides data on the effectiveness of using the polymer coating of the "Meadow of Health" fodder table in the technology of feeding dairy cows. As a result of the studies, it was found that the use of the "Meadow of Health" coating contributes to a significant decrease in microbial contamination: the number of microbial cells in group 1 after 5 months from the beginning of the study was more than 2, and 2 - 3.7 times less than in group 3 (P ≥ 0.95). The use of the cover of the fodder table "Meadow of Health" contributes to a reliably better (P ≥ 0.95) food consumption. Cows from the polymer feed table ate feed 7.0- 8.6% more than from concrete. Over the entire observation period, the cows of the 1st experimental group improved their performance by 13%, and the indicators of the 4th control group decreased by 9%. The increase in dairy productivity of cows is observed when transferring from the section with a concrete feed table to the section with the cover of the feed table "Meadow of Health." The average daily milk yield of cows with such a transfer within four months increases by an average of 0.4-13 kg. When transferring from a polymer feed table to a concrete one, a decrease in the average daily milk yield of cows is observed. Thus, the effect of the polymer coating of the feed table on the milk yield of cows was established. The calculation of the efficiency of using the polymer coating of the feed table showed that in the first month, due to the profit from the additionally received milk, the costs of the polymer coating pay off by 65.7-77.7%.

Many factors influence the results of incubation and the quality of young animals. One of the most important is the age of the chickens of the parent flock. The effect of chickens aged 35 weeks was studied. and younger, 36-45 weeks and 46 weeks. and the senior of the parent herd of the Ross 308 cross on the results of egg incubation and meat productivity of broilers obtained from chickens of different ages. It was found that the influence of the age of the chickens of the parent flock has a curvilinear relationship with the results of incubation of eggs obtained from them. Hatching, hatchability and fertilization of eggs at the age of a bird from 36 to 45 weeks. the results of incubation of chicken eggs were superior for 35 weeks. and less by 2.01%, 0.91% and 1.27% and eggs obtained from poultry for 46 weeks. and older by 8.45%, 4.42% and 8.80%, respectively. When fattening broiler chickens obtained from chickens of different ages, it was found that despite the more intensive growth of chickens from young birds and the high live weight of broilers at the end of fattening, obtained from chickens older than 46 weeks. The European productivity index for broiler chickens obtained from eggs at the age of 36-45 weeks was 358,6 and exceeded the first by 3,02% and the second by 1,11%. When portioning chicken carcasses– broilers of the Ross 308 cross were the most effective broilers obtained from chickens at the age of 46 weeks. and older. Thus, the influence of the age of the chickens of the parent herd on the results of incubation and meat productivity of broilers obtained from chickens of different ages has been established.

The article presents the results of the use of the drug “Butofan OR” in various dosages for transovarial treatment of hatching eggs and stimulation of embryogenesis in chickens of the highly productive meat cross “Cobb 500”. Despite the fact that in general the mechanisms of embryogenesis have been studied, there remains an open question about the effect of various drugs on the process of embryo development under the influence of paratypic factors. In particular, effective methods of using the drug “Butofan OR” for transovarial treatment of hatching eggs of parent flock chickens and stimulation of further development of young animals at different stages of ontogenesis have not yet been studied. The purpose of the work is to determine the effectiveness of using different doses of the drug “Butofan OR” during transovarial processing of eggs. “Butofan OR” in 1 ml contains butaphosphan – 100 mg and cyanocobalamin – 0.050 mg as active ingredients; excipients: methyl 4-hydroxybenzoate – 0.7-1.3 mg, purified water – up to 1 ml. The drug was specified in the following concentrations of the working solution: 01%, etc. It was found that when using the drug in experimental groups, the duration of withdrawal was reduced by 2 -4 hours. During pre-incubation treatment of eggs in all experimental groups, it was found that, taking into account incubation waste, hatchability increased by 5.14% and 6.71%, and hatchability by 7.03% and 7.82%. When assessing chickens at one day of age, it was found that in the 2nd experimental group, according to the set of indicators of the quality criterion of the “Pasgar” scale, the average score was 8.7, and according to the quality criteria of the “Optistart” scale, the average score was 9.2. The best performance was observed when processing hatching eggs in concentrations of 0.5% before placing them in the incubator and 5.0% on the 18.5th day of egg incubation. Transovarial treatment of hatching eggs had a positive effect on the viability and dynamics of live weight of hatched young animals. At the end of the technological growing period, the live weight of the chickens exceeded the results of the control analogues - by 6.91% (P <0.001) with the safety of the livestock - 99.0%. 

A pressing issue in industrial poultry farming is the search for feed additives and technologies that facilitate the realization of the genetic potential of agricultural poultry. One of the solutions to this problem is molecular genetic methods for studying the expression levels of productivity and resistance genes, which allow us to assess the impact of feed additives on health, productivity and product quality at the molecular level. The purpose of the presented study was to assess the potential of using Laminaria grits as a feed in the diet of industrial layers of the Lohmann White cross. The experiment was conducted at the vivarium of the International Laboratory of Molecular Genetics and Genomics of Poultry, FGBOU VO MGAVMiB-MVA named after K.I. Skryabin. Zootechnical research methods were used in the work. The study found that the egg-laying intensity for the entire period was higher in the 2nd experimental group and amounted to 97.77%, which is 2.09% more than the control, 1.94% more than the third experimental group and 1.19% more than the fourth experimental group. In the group of birds receiving bladderwrack, the indicator was at the level of 96.88%, which is 1.2% more than the control and 0.3% more than the fourth experimental group. The introduction of 15 g / kg of kelp contributed to an increase in the egg-laying intensity by 0.9%, compared to the control. Thus, in the course of the study, the effect of different rates of introducing Laminaria grits as a feed was assessed. The maximum egg production of 97.7% was noted with the addition of Laminaria to the feed (5 g / kg), which is 2.1% higher than the control. The results of the experiment form the basis for the development of new promising natural adaptogens that normalize the productivity of industrial cross-breed laying hens and ensure the production of biosafe poultry products.

In animal diets, due to the rejection of antibiotics and growth stimulants, alternative and safe additives are needed to improve their health and well-being. In this regard, biologically active components of plant origin, such as extracts and infusions from herbs and wood, dry plant biomass, including algae, are becoming relevant. According to many authors, seaweed can be used in poultry farming as part of feed components and feed additives both to improve the immune status and to normalize the microflora in the digestive tract. The recommended dosages of algae used to improve the quality of the resulting products range from 1% to 5% of dry weight. The purpose of the presented study was to study the effect of kelp grits on the expression of genes in the body of laying hens of the Lohmann White cross. The work used zootechnical methods and molecular biology methods. During the study, the effect of kelp grits on the expression of productivity genes in laying hens was assessed. The introduction of kelp at a rate of 5 g / kg into the diet of older laying hens contributed to the positive activation of productivity genes (OCX-32, OCX-36, CALB1) by 30-60%. The obtained results are the basis for the development of new biotechnologies that help extend the period of productive use of industrial cross-breed laying hens by improving egg production indicators. In order to increase egg production indicators, as well as to increase the expression of productivity and resistance genes of egg-laying hens, we recommend including a biologically active additive of kelp in the diets of laying hens at a rate of 5 g / kg of feed.

The article is dedicated to the study of endobiont ciliates inhabiting the gastrointestinal tract of various ungulate species, with a focus on their species, diversity, and dependence on diet and physiological characteristics. The study provides detailed data on the microbiota of the rumen in moose, the forestomachs of wild reindeer, mountain goats, and roe deer. In the moose (Alces alces), four species of ciliates were identified, belonging to three genera: Entodinium, Epidinium, and Diplodinium. These species include Entodinium exiguum, Epidinium ecaudatum ecaudatum, Epidinium ecaudatum cattaneoni, and Metadinium minorum. Studies of endobiont ciliates in wild reindeer inhabiting Yakutia revealed the presence of 14 ciliate species, belonging to six genera: Entodinium, Diplodinium, Eudiplodinium, Ostracodinium, Epidinium, and Dasitricha. Of these, six species were common across all investigated populations and were classified into four genera: Entodinium, Diplodinium, Eudiplodinium, and Epidinium. These findings indicate the diversity of the microbiota in reindeer, which is dependent on their ecosystem and diet.
In the mountain goat, five species of ciliates were found, belonging to three genera: Entodinium, Epidinium, and Eudiplodinium. Notably, Entodinium anteronucleatum was identified as species-specific for the mountain goat, making it unique in the context of the microbial biodiversity in the forestomachs of even-toed ungulates. As for the roe deer (Capreolus capreolus pygargus), two ciliate species were detected in its forestomachs: Entodinium dubardi and Entodinium exiguum, both belonging to the genus Entodinium. The study results emphasize the importance of species-specific nutrition and physiological characteristics in shaping the gastrointestinal microbiota. Furthermore, the potential of using endobiont ciliates for transplantation into the forestomachs of other animals is discussed, with the aim of improving their health and productivity.

Representatives of the predatory order have a similar anatomy of elbow flexors. However, due to the difference in lifestyles of individual predatory species, the abovementioned muscles are involved in the movement of the elbow joint in different ways. Using the basic principles of biomechanics allowed us to study the effect of each muscle at a certain point in the angle of the elbow joint. The material for the study was the corpses of a raccoon, raccoon dog and Mestizo dogs (weight 7-10 kg), delivered to the Department of Animal Anatomy from veterinary clinics in St. Petersburg and hunting farms in the Leningrad region. The research method was fine anatomical dissection. The moment of force is a physical quantity that is the product of the modulus of the force rotating the body by its shoulder and the sine of the angle between the shoulder and the modulus of force. Since sin(90º) =1, we built a perpendicular from the center of the axis to the force vector and this value was taken as the Moment Arm (MA). The fulcrum or center of the axis in this case is the center of the elbow joint. The force is represented as a vector, the direction of which is determined depending on the function of the muscle. The vector is based on the points of attachment of the muscle. Using the tpsDig2 program, we measured the Moment Arm of the muscles at different values of the angle of the elbow joint. The peak of the brachialis muscle in a raccoon stripper is at 72°, in a raccoon dog, the brachialis muscle is slightly involved in flexion of the elbow joint. The circular pronator in all individuals is weakly involved in flexion of the elbow joint. We have identified the biceps muscle of the shoulder and the shoulder muscle as the "main" flexors of the elbow joint, because at any value of the angle of the elbow joint, the muscles adhere to medium and high values. In dogs, the maximum range of motion of the elbow joint (MDD) is from 57° to 149°, in a raccoon from 45° to 158°, in a raccoon dog from 75° to 130°.

Intracranial hypertension is a frequently reported pathology of the brain. Its pathogenesis is based on hypersecretion of secretion and impaired reabsorption of cerebrospinal fluid (CSF). Its secretion is carried out due to vascular bodies (vascular plexuses), which are derivatives of its soft shell. According to their structure, they can be attributed to vascular epithelial organs. The production of cerebrospinal fluid depends on the functional activity of vascular bodies, which is primarily due to the structural and functional relationships between their epithelial cells and vessels of the microcirculatory bed. The main metabolic link of the latter is the capillaries at the level of which the bidirectional transport of substances (from tissues to the bloodstream and back) takes place]. Therefore, the intensity of metabolic processes occurring in vascular bodies during secretion of cerebrospinal fluid directly depends on the structure of the wall of their capillaries. Considering that the pathogenesis of intracranial hypertension is often based on hypersecretion of cerebrospinal fluid, as well as the inconsistency of the literature data concerning the structure of the microcirculatory bed of the vascular bodies of the brain, the task was set to establish the features of the ultrastructural organization of their capillaries. The study was carried out using the technique of electron microscopy. The ultrastructural organization of the capillaries of the vascular bodies of the lateral ventricles of the brain was chosen as the object. The material was fragments of tissues of the vascular bodies of the lateral ventricles of the brain of a domestic bull. The material was obtained during the planned slaughter of animals. Tissue samples were taken from five individuals aged 1.5 years who had no signs of damage to the nervous system. Their processing for the production of ultrathin sections was carried out according to generally accepted methods. The sections were contrasted with a 2.0% aqueous solution of uranyl acetate and a solution of lead citrate and studied on an electron microscope Jem-1011 (JEOL, Japan) at magnifications of 2500-3000. When designating cellular and non-cellular structures, terminology corresponding to the International Histological Nomenclature was used. It has been established that there are three types of capillaries in the villi of vascular bodies, which have features of their structural organization. At the same time, regardless of their morphological type, they are lined with fenestrated endothelium. There are no pericytes in the composition of the capillary wall of the first type. One layer of pericytes participates in the formation of the capillary wall of the second type. The walls of capillaries of the third type are characterized by the presence of a monolayer formed by several pericytes embedded in the cleavages of a thick basement membrane. The revealed ultrastructural features of the architectonics of the capillaries of the vascular bodies of the brain can serve as a comparative guideline in assessing their morphofunctional state, both normally and in the case of arterial hypertension of the brain.

Pig farming is a promising area of animal husbandry in the context of import substitution, the number of enterprises that breed this breed of pigs is increasing. Yorkshire people have high fertility, early puberty, a large daily increase in body weight and the resulting products are not only meat-sucking, but also bacon. The stomach of pigs performs the following functions, such as: formation of gastric juice and enzymes; promotion of a food coma, followed by the formation of chyme; transportation to the duodenum. In addition, knowledge of the basics of the formation of the cardiovascular system is necessary for veterinary specialists engaged in various manipulations in the abdominal cavity. Blood drainage from the gastrointestinal tract is of great diagnostic importance in various diseases associated with the digestive system, such as: gastritis, gastroenteritis, gastric ulcer, intestinal obstruction, portosystemic shunts Cadaveric material for research was delivered to the Department of Animal Anatomy of the Federal State Budgetary Educational Institution of Higher Education of the Leningrad Region from the pig breeding complex. The objects are corpses of Yorkshire pigs of two age groups: newborns (1 day of postnatal ontogenesis) and 30 days from birth. To study the age and breed characteristics of the venous bed of pigs, a set of modern anatomical research methods was used: fine anatomical dissection; filling of the venous bed with latex followed by macromorphometry; vasorentgenography. In the course of our study, it was found that from the wall of the stomach in the area of its great curvature and large omentum, venous blood outflows into the right and left gastro-omentum veins, where the left gastro-omentum vein flows into the splenic vein, collecting blood from the wall of the stomach of its cardiac department and tissues of the spleen, and the right gastro-omentum the vein merges with the gastrointestinal duodenum to form the right gastric vein, diverting blood from the stomach wall of its pyloric section and the initial part of the duodenum. Numerous small veins of the diverticulum merge into the left gastric vein. This is an anatomical and topographic feature of the venous bed of Yorkshire pigs.

Currently, polysaccharides with various specific properties are used quite often in different industries and spheres of production. The polysaccharide chitosan has proven itself well in modern medicine. Chitosan is a natural polymer, its unique feature is the ability to inhibit viral infections, and it also exhibits the properties of an enterosorbent, a factor regulating the acidity of gastric juice and is able to prevent the development of phage infections in an infected culture of microorganisms. Thus, in the conditions of OOO Agrofirma Rubezh, Pugachev District, Saratov Region, the biological safety and economic feasibility of using the polysaccharide chitosan in the diet of Large White pigs were studied. The article considers the effect of the polysaccharide chitosan on the general homeostasis of the pigs' body. On the basis of the veterinary clinic of the Vavilov University, a comparative analysis was conducted throughout the entire experimental period for the following hematological parameters: erythrocytes, 1012 / l; hematocrit, %; hemoglobin, g/l; leukocytes, 109/l; total protein, g/l; ALT, U/l; AST U/l; creatinine, mmol/l; urea, mmol/l; bilirubin, mmol/ l. In addition to studying changes in morphological and biochemical blood parameters, the work also monitored the growth rates of the control and experimental groups. The data obtained prove that the studied aminopolysaccharide does not have a negative effect on the body of the animals studied, but on the contrary, normalizes the indicators of internal homeostasis and improves the course of metabolic processes in the body of pigs. According to the results of the study, an increase in the level of profitability of animals in the experimental group was established due to a decrease in the cost of feed consumed. Accordingly, this indicates an improvement in the economic performance of the farm.

Stress in animals poses a serious problem that affects their health, productivity, and overall well-being. In modern livestock farming, it is extremely important to develop methods that help minimize stress and its consequences. One such approach is the use of organic acids, which have a positive impact on metabolism and adaptive processes in animals. The aim of this study was to investigate the effects of the organic-mineral supplement Klim on metabolic processes under conditions of cold stress. For this purpose, a study was conducted with laboratory rats, which were divided into three groups: intact, control (subjected to cold stress), and experimental (receiving the Klim supplement under stress conditions). Cold stress was modeled by placing the animals in a freezer at a temperature of -18°C for 4 hours. The results showed that stress significantly impaired protein metabolism indicators and activated catabolic processes in the control group, as evidenced by increased levels of total protein and urea, as well as decreased alkaline phosphatase activity. In the experimental group receiving the Klim supplement, there were no significant changes in protein metabolism parameters, indicating its effectiveness in reducing the negative effects of stress. The study confirmed that the Klim supplement contributed to the improvement of the overall condition of the animals and their adaptation to stress conditions, highlighting the potential for using organic additives in livestock farming to enhance health and productivity. The results indicate the need for further research into the application of various additives to minimize stress and improve the well-being of animals in the agricultural sector.

Chronic kidney disease (CKD) is a wide spread human illness defined as long-lasting abnormalities of kidney structure or function due to fibrosis and destruction of the normal architecture of the kidney. Pathophysiology of this process is not completely understood; thus, development of prophylactics, early detection and therapy of initial stage are complicated. Therefore, inducing of CKD in local research centers is a relevant objective for Russian pharmacology. 5/6 nephrectomy in rats is recommended by many scientists as “gold standard'” for this pathology. In this study CKD was successfully induced in Wistar rats using 5/6 nephrectomy, modified to meet the requirements of a large preclinical center. Two animal groups (control and pathology) underwent a complex of clinical diagnostic tests and pathological examination, so the CKD criteria could be specified. Elevated blood pressure and decreased glomerular filtration rate enabled assessment of the disease progress in experimental animals. At the end of the study these symptoms were partly reversible revealing prominent adaptability of rat kidney. In order to confirm pathology formation, we performed histological (hematoxylin-eosin, Masson's trichrome) and immonohistochemical (CD68, Caspase3) staining of kidney sections. During pathomorphological study we found alterations specific for CKD: apoptosis of tubule epithelium and fibrosis area crowded by CD68+ macrophages. Thus, we identified antemortem and postmortem criteria of CKD induced by modified 5/6 nephrectomy in rats in Russian research center.

Modern medical and veterinary practice is increasingly focused on the use of organsparing and genetically molecular technologies that help restore lost functions. In this context, cellular technologies, including the creation of recombinant chemokines and monoclonal antibodies, play an important role in the targeted therapy of serious diseases. Cellular regenerative medicine finds its application in the healing of skin and muscle structures, especially in horses. In this paper, the possibility of using the secretome of mesenchymal stromal cells (MSCs) for the treatment of inflammatory diseases of the bronchopulmonary system in horses suffering from asthma is considered. The study was conducted on the basis of a retrospective analysis of observations of 91 horses that had signs of asthma (EAS). 70 of these horses were treated with the secret of MSC (the drug Reparin helper). Both mares and geldings aged 10-21 years took part in short-term observations. The secret was administered intrabronchially, inhaled and intravenously. The effectiveness of the treatment was assessed by changes in the clinical condition and possible adverse reactions. Analysis of the results of short-term observations showed that the majority of patients treated with secret MSC had no negative reactions. The clinical efficacy of the drug varied depending on the method of administration: the intratracheal method showed no improvement, while inhalation and intravenous administration led to positive results. Horses with severe asthma had a high degree of exercise tolerance against the background of the drug, which confirms its effectiveness. Horses that received the secret of MSC for a long time showed stable remission for 6-12 months. Among the 70 cases of the use of the MSC secretome, the results showed the most positive effects in horses with severe asthma. More than 20% of them successfully received additional therapy for two years, demonstrating long periods of remission. The study confirms the potential of using the MSC secretome in veterinary practice, and the data obtained may be useful for humane medicine.

Quite often, a veterinarian in daily practice is faced with the need for access to the pelvic bones during surgical intervention of various pathologies of this area in dogs and cats. Dogs with severe pelvic injuries received as a result of an accident, falls from a height or under other circumstances are regularly admitted to veterinary clinics in St. Petersburg. Very often, radiography reveals fractures of the iliac body, intra-articular fractures of the articular cavity of the pelvis of varying complexity and localization, fractures of the concave branch of the sciatic bone. Also, in young animals, cases of developmental disorders (dysplasia) of the hip joints are common, requiring correction of angles in the pelvic bones by osteotomy. The purpose of the study is to study and provide anatomical and topographic justification for access to pelvic bones by osteotomy of the great trochanter of the femur during osteosynthesis of fractures of the body of the pubis, intra–articular fractures of the articular cavity of the pelvis, acetabular branch of the sciatic bone, sciatic spine, combined fractures of the listed structures. The work on the study was carried out on the material and technical base of the network of veterinary clinics "TrustVet" and at the Department of Animal Anatomy of the Federal State Budgetary Educational Institution of Higher Education. As a result of our research, we were convinced that performing access through osteotomy of the great trochanter of the femur allows us to significantly atraumatic for the gluteal muscles, piriformis muscles, rotator muscles, as well as for vessels and nerves to find an approach to the hip joint, the iliac body, the hollow branch of the sciatic bone. This access provides the greatest comfort, convenience and safety when manipulating surgical treatment objects in an operating wound. Consolidation of the osteotomy line was completed in all cases after 3-5 weeks. In no case did such complications develop as: failure of the metal structure and subsequent diastasis of the great trochanter of the femur, contracture of the muscles of the gluteal or posterior femoral groups, neurological deficiency, bleeding, formation of seromas and other complications.

The article presents the peculiarities of the pathological process occurring in the dental alveoli of jaw bones in mesocephalic dogs of the older age group (10-15 years old) subjected to lifetime tooth extraction. The study was conducted on the basis of the Department of Animal Diseases and Veterinary Sanitary Examination of Saratov State University of Genetics, Biotechnology and Engineering by N.I. Vavilov and the Department of Anatomy and Histology of Animals named after Prof. A.F. Klimov of Moscow State Academy of Veterinary Medicine and Biotechnology – MVA by K. I. Skryabin. The object of the study were dogs with mesocephalic head shape (n=15) at the age of -15 years. Upper and lower jaws served as the material for the study. The method of anatomical dissection was used in order to obtain the head skeleton for further cranioscopy, which included evaluation of the alveolar process on both jaws. Based on the results of the study, it was found that regardless of the localization of the jawbone, all pathological processes in its dental alveoli had the same character of course. It was revealed that the structural changes in tooth loss were primarily characterized by filling of the cavity with spongy bone substance, which grew out of the interplate space of the jaw bones. Due to the filling of the alveolar cavity, the cancellous bone replaced the vestibular compact bone plate of the alveolar process on both jawbones. The obtained data are basic for improvement of classical and development of new methods of differential diagnostics and methods of extirpation in dentistry of small pets.

Under experimental conditions, the effect of different feed additives (prebiotic, probiotic, sorbent) on the structure of the rectus head of quadriceps femoris muscle of broiler chickens of meat cross “Cobb-500” (age 35 days) was studied on the basis of light and transmission electron microscopy and micromorphometry methods. The chickens were divided into four groups. In the control group chickens received the basic diet, and in three experimental groups prebiotic, probiotic, sorbent of domestic production was added to it. Light-optical studies determined the ratio of muscle fibers and connective tissue component in the muscle structure, dimensional indices of muscle fibers and their bundles, thickness of endomysium and perimysium, the degree of vascularization of the muscle. At the ultrastructural level, the thickness and packing density of myofibrils, as well as the degree of development of the mitochondrial apparatus of muscle fibers were assessed. It was shown that probiotic administration was accompanied by compaction of muscle structure due to a decrease in the representation of connective tissue component, an increase in the number of largediameter muscle fibers, and better development of mitochondrial network in muscle fibers. Application of prebiotic resulted in activation of metabolic processes in muscle fibers against the background of increase in the total area of mitochondria, increase in the representation of large fibers in the structure of muscle bundles, but the muscle structure was loose due to significant representation of connective tissue component of muscle. When sorbent was used, the muscle structure was characterized by an increase in the representation of connective tissue (more than in other groups), which led to lose packing of muscle fibers in bundles, as well as the predominance of muscle fibers of small and medium diameter in the structure, which was accompanied by an insignificant increase in the total area of mitochondria. The obtained data indicate a different effect of feed additives on tissue metabolism, which leads to changes in the structure of quadriceps muscle of broiler chickens of experimental groups. The obtained data should be taken into account when formulating diets in industrial poultry farming.

Goat breeding in Russia is one of the rapidly developing branches of animal husbandry. The aim of this work was to study a number of parameters of the antioxidant activity of goat milk. The main parameters of milk from 48 goats (“Bylinkino” peasant farm, Moscow region) were obtained and studied. The highest average value (23.5 mg/ l) of total concentration of water-soluble antioxidants (TAWSA) was noted in the highest-yielding goats (group 3), which is 25.0% and 48.7% higher than in groups 2 and 1, respectively. In group 2, the average value of TAWSA (18.8 mg/l) was significantly lower than in group 3, but almost 19.0% higher than in the control group 1 (in the lowest-yielding goats). In case of group 1, the total number of strong and very strong correlations between the main indicators of goat milk is significantly higher than in groups 2 and 3. Thus, in group 1, very strong positive correlations are observed between TAWSA and fat, lactose, etc., as well as moderate positive correlations - between TAWSA and indicators of total and true protein. Negative strong (moderate) correlations at the level were found between TAWSA and morning (daily) milk yield. The latter negative correlations indicate the inability of the organism to synthesize biologically active substances in the volumes that give high TAWSA values and are necessary to maintain the antioxidant activity of goat milk at a sufficient level for group 1. 

The results of a recent study of the bioelectrical activity of the somatosensory cortex of the rat brain indicate the involvement of this structure in spatial orientation processes. The authors showed that the nature of the bioelectrical activity can change depending on the point in space where the animal is located. At the same time, the area of the primary somatosensory cortex, which contains the representations of the whiskers - the barrel cortex - remained unexplored. Previously, we conducted studies of the ability of rats to spatial learning, and then studied the structural organization of the brain in some of these animals. Thus, the goal of this work is to search for possible correlations between the parameters characterizing the behavior of rats during spatial learning and the data obtained in histomorphological studies of the somatosensory cortex of these rats. The object of the study is the data obtained as a result of testing in an eight-arm radial maze and in morphometric studies of the somatosensory cortex of the Wistar and DATHET rats. Based on the results of the analysis, we made the assumption that success in spatial learning is directly related to the number of neurons in layer 4. In layer 5, this role is assigned primarily to glia. The differences between the groups of animals here are quantitative. Qualitative differences were observed in relation to layers 2/3 and 6. Thus, Wistar rats are characterized by direct correlations of behavioral indicators with the number of neurons in the first of the above layers, and in layer 6 - with the density of glia distribution. At the same time, such correlations are absent in DAT-HET rats

Modeling of oocyte maturation systems in farm animals is based on the available information on the composition of follicular fluid (FF), however, there are no data on the hormonal status of porcine follicular fluid in relation to the viability and functional state of the lipidome in granulosa cells (GCs) in the dynamics of folliculogenesis. We analyzed the hormonal profile (LH, FSH, T3, T4, cortisol) of porcine antral follicle fluid and obtained data on the effect of these hormones on the viability and lipid content (lipid droplets-LDs) of porcine GCs in follicles of different diameters (ø <3 mm, ø 3-5 mm and ø>5 mm). An inverse correlation was found between the proportion of GCs with high fluorescence intensity of the lipid droplet complex – NileRed (IFNileRed/LD - a marker of lipid droplets content) and the concentration of cortisol in the dynamics of folliculogenesis (-0.830, p<0.05), as well as an inverse correlation between the cortisol content and the proportion of viable cells (- 0.995, p<0.05). A direct correlation was found between the content of both T3 and T4 with IFNileRed/LD (0.901, 0.946, p<0.05) in GCs, which probably suggests accumulation of the energy substrate in the cytosol. There were no reliable correlation values in the content of LH in the FF and the proportion of GCs with high IFNileRed/LD intensity. The high level of correlation in the concentration of T3, T4 in the FF and cortisol with the lipid’s content in the GCs indicates a significant influence of these hormones on the energy reserve and viability of the GCs during folliculogenesis and allows us to consider them as potential candidates for an indepth study of the mechanisms of metabolic disorders that provoke abnormalities in the development of offspring obtained at in vitro maturation and fertilization of female gametes, as well as for modeling the composition of the media for the formation of a mature porcine ovum in vitro. 

The main use of genetic data is to assess the reliability of origin, since errors in pedigrees negatively affect the rate of genetic growth. Initially, the assessment of the pedigree of breeding livestock was carried out using various DNA technologies: from blood groups, then using microsatellite markers, however, now the possibility of using single nucleotide polymorphisms (SNP) in practice is being increasingly studied, due to their ability to increase the accuracy of genetic research. One of such genotyping systems is AgriSeq panels (targeted sequencing technology), which allow analyzing specific regions of the genome (loci) associated with a variety of traits in animals. The purpose of the work: to study the effectiveness of identifying and prevalence of loci from the proposed set of SNPs in the examination of new generations of sheep of the Manych Merino breed. The material for the study was data from targeted sequencing of the genomes of Russian sheep breeds according to the formed set of loci in order to identify singlenucleotide polymorphisms. The object of the study was sheep born in 2021 at the age of 12 months (DNA sampling was carried out in 2022) of the Manych merino breed. The proposed locus panel, modified after validation on the next generation of animals, contains 389 substitutions suitable for genotyping by sequencing and 242 polymorphisms associated with animal meat productivity. The indicators of the frequency of occurrence of substitutions in the group of selected animals obtained as a result of research allow us to conclude that the polymorphisms, we have selected are located in loci that are not subject to significant rearrangements for several generations and can be informative for quite a long time. The analysis allows us to conclude that after modification of the set of loci, the panel for genotyping by sequencing in the Manych merino showed high efficiency in identifying all variants of genotypes.

Reindeer herding is an important branch of animal husbandry in Russia, especially in the northern regions of the country. Genomic selection is a method based on the analysis of genetic data on animals in order to select individuals with certain genetic characteristics for breeding. By genetic selecting, it is possible to increase the efficiency of breeding programs, reduce the time to obtain the desired results and improve the quality of the offspring. The FSHR (Follicle-Stimulating Hormone Receptor) gene encodes a protein that is a receptor for follicle-stimulating hormone (FSH). Studying the FSHR gene is important for understanding the mechanisms of regulation of the reproductive system and searching for new genetic markers associated with reproductive functions in different animal species, including reindeer. The aim of the study was to study the polymorphism of the FSHR gene in female reindeer of the Yamalo-Nenets Autonomous Okrug of the Russian Federation. DNA samples from 43 reindeer females (Rangifer tarandus) belonging to the same herd were analyzed. We sequenced a 2208 bp FSHR region containing the fifth intron of the gene in females from the Yamal Peninsula. During the study of the region, we found two singlenucleotide polymorphisms: G28578A and G29110A. The first polymorphism was located in the second nucleotide of the codon and led to the replacement of serine with asparagine in the amino acid sequence of the protein. The second polymorphism was synonymous and did not lead to a change in the structure of the protein.

Despite the fact that reindeer (Rangifer tarandus) are an important commercial species for providing food for the population in difficult living conditions, they are currently poorly studied due to the complexity of conducting research. This is especially true for physiological characteristics associated with reproduction, the gaps in which complicate the implementation of modern assisted reproductive technologies. Deep knowledge of endogenous hormonal regulation in different physiological periods of female reindeer could allow us to manage the reproductive function. The work is devoted to the analysis of concentrations of steroid hormones 17β - estradiol and progesterone, as well as gonadotropins - follicle-stimulating and luteinizing hormones of females during the breeding season. The object of the study were female (female) reindeer (n = 31). The habitat is a reindeer farm in the north of Western Siberia, in the Yamalo-Nenets Autonomous Okrug of Russia. The total sample was divided into two groups: group 1 (n=16) did not calve and group 2 (n=15) did. The hormone levels in the blood serum were determined using enzyme immunoassay. The results of the studies show that in the group of does in the late calving period, the concentrations of estradiol and progesterone were significantly higher (p<0.01) compared to the group of does after calving. At the same time, a tendency towards an increase in follicle-stimulating hormone can be noted after calving. A negative correlation was recorded in the case of progesterone and luteinizing hormone in the group of does in the early calving period (r=-0.735, p<0.01). A positive correlation was found between follicle-stimulating and luteinizing hormones (r=0.811, p<0.01). In the group of animals in the late calving period, a positive correlation was found between progesterone and estradiol (r=0.641, p<0.01). The results obtained suggest that in female reindeer, the resumption of sexual cycles occurs according to a similar hormonal scenario, in which the level of steroid hormones decreases after calving, and the concentration of gonadotropic hormones, on the contrary, gradually increases with higher FSH dynamics, compared to LH.

Reindeer (Rangifer tarandus) are a polycyclic animal species with a limited breeding season. Although the main reproductive season for reindeer occurs in autumn, the onset of this period varies even within one geographical area, which is due to feeding factors related to the fatness of animals, as well as temperature, light and other climatic conditions. Therefore, a thorough understanding of the female reindeer reproductive cycles is important for managing reproductive processes, including through assisted reproductive technologies, and increasing the productivity of populations. Hormone levels is a critical aspect in the practice of artificial insemination of animals, since hormonal status has a significant impact on reproductive functions. The aim of our study is to study the hormones concentration: estradiol, progesterone, luteinizing hormone (LH) - in the blood of female reindeer in summer and autumn. The object of the study were clinically healthy female domestic reindeer (n = 3), that live in Pushkin. Blood was taken from June to October, the time interval between blood sampling was on average 1 week. The level of hormones was determined using enzyme immunoassay. Based on changes in LH and progesterone levels, the estrus cycles in the studied animals occurred from July to late October. The dynamics of changes in LH levels at the beginning of the rut season differed in all three animals. In all animals, cyclic increases in progesterone were observed on average every 14 days with the onset of the rut season. All the studied hormones in reindeer female demonstrated moderate and weak reliable correlations.

Reindeer husbandry is a historically established main branch of animal husbandry in the northern regions of the Russian Federation. Despite the active of domestic reindeer breeding within the northern latitudes of our country, the features of the biological processes of this animal species remain incompletely understood. The importance is a detailed study the reproductive system physiology, which is relevant in light of the prospects for introducing assisted reproductive technologies into reindeer husbandry practice in order to intensify the selection process. Assisted reproductive technologies in reindeer husbandry are currently not used even in breeding herds due to the low level of development, although their introduction can significantly reduce the time and financial costs of selection and breeding work carried out to improve the productive qualities of domestic reindeer breeds. In mammals, the sexual process is under the complex subordinate control of neurohumoral mechanisms, which are based on changes in hormonal status, that is, the levels and ratios of the hormones in accordance with the physiological cycle. Reindeer are the least studied productive farm animals in terms of reproduction. The current trend is to study the hormonal regulation of reproductive processes in female reindeer in different physiological states, such as anestrus, rut, pregnancy, and the post-calving period. We studied the concentration of estradiol, progesterone, and luteinizing hormone (LH) in the blood of female reindeer before the rut (early summer, early autumn, and at the beginning of the rut). The levels of hormones were determined using enzyme immunoassay. The study determined the level hormones in physiologically healthy female domestic reindeer in the early summer and early autumn periods and at the beginning of the rut. The results obtained showed a statistically significant decrease in the concentration of progesterone and estradiol. A decrease in LH was recorded in the warm period with an increase towards the breeding period.

The identification of genetic substitutions affecting the malefertility attracts the attention of many researchers. However, in Russia, insufficient attention is currently paid to the study and use of the obtained genetic data related to the quality of animal sperm. As a result of GWAS analysis in 2022, marker single nucleotide polymorphisms were identified and candidate genes GRM8, FSHR, INHA, IMMP1L were proposed. The task was to sequence candidate loci to identify polymorphisms that determine the formation of traits associated with sperm quality for the development of marker selection and genome editing programs. As a result of the study, a number of single nucleotide polymorphisms were found in the GRM8, FSHR, INHA, IMMP1L genes. After the analysis, the effect of the detected SNPs in the GRM8 gene on sperm quality in stallions of various breeds was discovered. Also, based on the obtained SNPs located in the GRM8 gene, a dendrogram was constructed. As a result of the analysis of the obtained dendrogram, the stallion sample was divided into 2 main branches. Stallions of the left branch are superior to stallions of the right in terms of volume, sperm concentration, total motility, stimulation of respiratory activity 2.4 DNF of fresh sperm and after cryopreservation (by 3.28 ml, by 9.62 million/ml, by 3.6%, by 0.16 and 0.46, respectively). However, individuals of the right branch are superior to individuals of the other branch in terms of progressive motility of fresh sperm, progressive motility after thawing (by 18.44% and by 1.54%, respectively). New knowledge was obtained about the genetic polymorphism of exonic regions of the GRM8, FSHR, INHA, IMMP1L genes in stallions of different breeds.

The aim of this study was to investigate the effect of mesenchymal stem cell derivative (lysate) from adipose tissue (AT) and bone marrow (BM) of bulls on the quality of native sperm. A total of 10 samples were taken. Each sample was divided into aliquots (after centrifugation (7 min 600 rpm) and removal of seminal plasma) according to the following groups: control (sperm 7x10¹⁰ cells/ml + PBS buffer 100 μl), the first experimental (sperm 7x10¹⁰ cells/ml + BM MSC lysate 2x10⁸ cells/ml), the second experimental (sperm 7x10¹⁰ cells/ml + AT MSC lysate 2x10⁸ cells/ml).A four-stage assessment of sperm quality was carried out: 0, 2 and 4 hours of incubation at a temperature of 37℃.According to the results of the studies, a reliable decrease in the number of normal spermatozoa was recorded when assessing 4-hour sperm incubation.At the same time, the difference in values in the control and first experimental groups was 1.3 times (p < 0.05 for both groups), in the second experimental - 1.4 times (p < 0.05) compared with the data of 0 hours of incubation.The highest number of morphologically normal spermatozoa was recorded in the first experimental group, when incubating spermatozoa with bone marrow MSC secretion products.A statistically significant decrease in the number of progressively moving spermatozoa was obtained after 2 and 4 hours of incubation compared with the data obtained when assessing motility at 0 hours of incubation.Thus, the difference in values in the control group was 1.4 (2 and 4 hours, p<0.01), in the first experimental group - 1.1 (p<0.05) and 1.4 (p<0.01), in the second experimental group - 1.2 (p<0.05) and 1.6 (p<0.05) times 2 and 4 hours, respectively.The highest number of progressively moving spermatozoa was recorded during the interaction of bovine germ cells with the MSC lysate during two hours of incubation, obtained from the bone marrow and amounted to 74.75±2.39%.

The aim of the study was to establish the efficiency of using mesenchymal stem cells from adipose tissue and bone marrow of goats after sperm cryopreservation. The results of four-hour incubation of sperm samples after thawing indicate a reliable difference in the values during incubation with mesenchymal stem cells (MSCs) from adipose tissue/bone marrow and without them (OptiXcell medium). Thus, during four -hour incubation of sperm after thawing, a statistically significant decrease in the number of normal spermatozoa was noted in all study groups. At the same time, the difference in values in the control group was 1.3 (p<0.01, 2 hours) and 1.4 (p<0.01, 4 hours) times; the first experimental group - 1.1 (p<0.01, 4 hours) times; the second experimental group – 1.1 (p < 0.01, 2 hours) and 1.3 (p < 0.01, 4 hours) times compared to the results of 0 hours of incubation. Samples of the control and first experimental groups had the same dynamics of reliable changes in sperm motility during four-hour incubation after thawing – a statistically significant decrease in the number of progressively moving sperm by 1.6 times (p < 0.05 – control group, p < 0.01 – first experimental group), and, on the contrary, a reliable increase in the number of non-progressively moving sperm by 1.3 times (p < 0.05 for both groups). Pronounced motility activity was observed in the sperm of the first experimental group upon completion of 4-hour incubation, equal to 21.45 ± 4.58%. The highest number of viable spermatozoa was registered in the first experimental group with 4-hour incubation of samples with MSC obtained from bone marrow - 37.13±2.21%, the highest number of spermatozoa with intact acrosomes - in the second experimental group (MSC AT). Thus, it can be assumed that MSC has a regenerative effect on the structure of spermatozoa after cryopreservation. To reveal the mechanism of the effect of MSC on the structure of spermatozoa, it is necessary to continue research.

One of the promising areas for preserving female reproductive cells of the Aves class is the use of embryonic tissues of reproductive organs and cells. Evaluation of the effectiveness of freezing methods for female reproductive organs of birds should be based on simplicity and availability. The chicken chorioallantoic membrane (CAM) model can be an accessible and effective approach to assessing the quality of frozen/ thawed avian ovarian tissues for subsequent orthotopic transplantation. The aim of the study was to determine the age of chicken embryos for obtaining sex-differentiated gonads and to evaluate the viability of transplanted embryonic female gonads on the chorioallantoic membrane by their neovascularization in the mesenchyme for further use of these screening methods in cryopreservation of embryonic female gametes of chickens. To obtain embryonic female gonads, fertilized eggs of Russian White chickens were used after incubation for 9 days - 10 pcs, and for 17 days - 10 pcs (in 3 replicates). The number of vascularized donor gonads after transplantation to the recipient's CAM from 9-day-old embryos was 75.0% of the total number of transplants; from 17-dayold embryos it was 63.6%. The presented data are intended for practical evaluation of the model of transplantation of donor embryonic ovarian tissue using the recipient's CAM for the purpose of its subsequent use in assessing the effectiveness of the vitrification protocol for embryonic gonadal tissues of chickens, as well as in the protocol for obtaining gonadal germ cells (GGCs) from embryonic ovarian tissues of chickens from 9-day-old embryos and transplantation of embryonic ovarian tissues from 17-day-old-embryos

A serious problem for cattle breeding in the warm season is the threat of heat stress in animals, which causes significant economic losses for the entire industry, while having a negative impact on the productivity of dairy cows, as well as the composition of the milk produced. Daily monitoring of temperature and humidity by special electronic sensors in livestock premises and further calculation of the temperature and humidity index (THI) were chosen as an indicator of thermal stress in dairy cows, after which a link was established between the microclimate of the farm and financial losses. Four farms with different herd management systems, ventilation systems, milking methods and manure disposal were selected as experimental agricultural enterprises. The lowest milk losses were recorded at a megafarm with loose maintenance, robotic milking and an innovative automatic ventilation system. The greatest losses, due to the effect of heat shock on dairy cows, were incurred by a farm with tethered housing, milking in a milk pipeline and not equipped with a ventilation system. At the same time, the indicator of the content of the mass fraction of fat in milk remained relatively stable, the decline was noted only after cases of sharp jumps in the temperature and humidity index in the livestock premises. Most often, such jumps, and the subsequent decline in productivity, occurred in the second half of June and the first half of July 2024. Stabilization of both the temperature and humidity conditions on farms and reduction of the negative effects of heat stress occurred at the end of August and the first half of September. On average, 57 days with critical indicators of the temperature and humidity index were registered for the entire season.

The aim of the work was to provide a population genetic characteristic of the Kholmogorsky breed of the Tatarstan type of the Republic of Tatarstan for the MC4R gene (melanocortin 4 receptor). As a result of genotyping by the PCR-RFLP method for the MC4R - HpySE526I gene locus, 2 alleles and 3 genotypes were identified. The frequency of alleles: C - 0.434 and G - 0.566; and frequency of genotypes: CC - 20.9, CG - 45.0 and GG - 34.1%. The chi-square test (χ²) showed that the studied population the Hardy–Weinberg genetic equilibrium is not disturbed. A negative Selender coefficient (D) indicates outbreeding in the population. Monitoring of works on studying the polymorphism of the gene 1069C˃G (Leu286Val) shows a significant variability in the ratio of polymorphic forms of the MC4R gene in different cattle populations depending on their geographic and breed affiliation. On average, for all the considered cattle breeds of the world populations, the frequency of alleles of the MC4R gene is 0.537 and 0.463 for the allele C and G, respectively. The ratio of the CC, CG and GG genotypes of the MC4R gene for all analyzed cattle populations averaged 32.5, 42.3 and 25.2%. The analysis carried out using the data of foreign scientists and the results obtained in our study characterizes the world populations of cattle as genetically biodiverse, possessing genetic polymorphism for the MC4R gene with a high degree of heterozygosity. This research was supported by FASO Russia project, registration number 122011800138-7.

The obtained data biologically confirm the feasibility of breeding chickens by the size of the egg yolk to increase their nutritional and biotechnological value. In the yolks of eggs of chickens of group III (with a yolk weight of M+0.5σ), the prevalence of triglycerides over group I (with a yolk weight of M-0.5σ) and II (with a yolk weight of M±0.3σ) was observed: by 24.0% (p<0.001) and 12.4%, cholesterol by 37.2% (p<0.01) and 13.5% and total protein by 22.8% (p<0.01) and 5.2%, respectively. It was established that the concentrations of estradiol, estriol and estrone change during the 6-hour period of the ovulatory cycle of chickens under study. The fluctuations of the 3 hormones in groups I and III do not coincide, in group II they coincide in two periods: 1-0 hours before laying an egg - a decline and 1-2 hours after laying an egg - an increase. In hens of groups I and II, changes in individual estrogen concentrations are subject to frequent fluctuations - declines and increases, and in hens of group III, hormone levels showed gradual decreases and increases. The predominant estrogen hormone in the blood serum of hens of the 3 groups in the studied periods of the ovulatory cycle is estriol (p < 0.001), the concentration of which is on average 1.77 ... 2.30 nmol / l for the entire period, while estradiol is 1.30 ... 1.47 nmol / l and estrone is 0.18 ... 0.23 nmol / l. The percentage of individual hormones in the sum of estrogens in the studied periods has different trends, so on average for the entire period for Group I the following percentage of estradiol, estriol and estrone in the sum of estrogens is characteristic: 37.2%, 58.2% and 4.6%, respectively, for Group II - 39.4%, 53.6% and 7.0%, and for Group III - 36.8%, 57.6% and 5.6%. Consequently, the ratios of estrogens in the groups of hens by periods of the ovulatory cycle are different. The obtained differences in the concentrations of estrogens by periods, and, consequently, the percentage of individual hormones to the sum of estrogens and their ratios to each other, are associated with differences in the synthesis of these hormones by the follicular membranes of oocytes in hens of the 3 studied groups, which affects the content of ovogenic substances of the yolk in the blood, and subsequently on the weight of the yolk of hens' eggs. Also, in the body of chickens, by changing the concentrations of estrogens and, consequently, their ratios, which are the executive mechanisms in the regulation of reproductive function in chickens in the general chain hypothalamus-pituitary-ovary, a switching of synthetic systems occurs during the ovulatory cycle, which ensure, in addition to the formation of ovogenic substances of the yolk, the formation of protein and mineral components of the shell.

Most equine artificial insemination is now carried out using chilled semen, as its fertilizing capacity is higher than cryopreserved semen. However, the possibility of long-term storage of chilled sperm is limited. The use of extenders allows to prolong the preservation of the biological value of chilled sperm. In this study, the survival rate and morphology of chilled stallion sperm were assessed using different extenders. Four extenders were used: LHСZh, recommended by the All-Russian Research Institute of Horse Breeding, Kenny, widely used abroad, extender for cooling sperm of the All -Russian Research Institute of Farm Animal Genetics and Breeding, and an experimental extender based on TRIS and fructose. A reliable difference was observed in the total and progressive motility of sperm diluted with the experimental and other media during storage for 24, 48 (P˂0.05) and 72 hours (P˂0.01). After storage for 72 hours, sperm diluted with the experimental extender had an average total motility over 50% and a progressive motility 48.2±3.67%, which makes it possible to use it for artificial insemination. Evaluation of sperm morphology showed good preservation of cells during 72-hour storage at 4-5 0C when using all extenders. The results of this study showed preservation of sperm quality necessary for artificial insemination for 48 hours, and when diluted with the experimental extender for 72 hours.

The article presents the results of a study on the effect of some steroidal and nonsteroidal anti-inflammatory drugs on the rate of formation (coagulation) and the rate of retraction (contraction) of clots prepared from erythrocyte-free plasma enriched with platelets. It was found that high concentrations of anti-inflammatory drugs of these groups, through selective effects on platelet metabolism, change the rate and intensity of coagulation and clot contractionin different ways. The nonsteroidal anti-inflammatory drug meloxicam does not change the time of clot formation (coagulation), but significantly accelerates its contraction. It is suggested that the acceleration of the onset and complete completion of contraction is due to the fact that meloxicam suppresses platelet cyclooxygenase of the second type. As a result, platelets stop producing prostacyclin, which is an antagonist of the platelet activator thromboxane-A2. Another nonsteroidal antiinflammatory drug ketorol, on the contrary, significantly prolongs the onset of coagulation of the clot and completely suppresses its contraction. This is due to the fact that this drug is a strong inhibitor of cyclooxygenase of the first type. Accordingly, the platelet activator trom-boxan-A2, which is dependent on this enzyme, ceases to be synthesized. The steroidal anti-inflammatory drug dexamethasone, in comparison with the control, slightly accelerates both the time of onset of coagulation and the time of onset of clot contraception. However, this effect has low statistical validity. The results obtained are indirect evidence that meloxicam and dexamethasone do not prevent platelet activation. And, therefore, they can be used in parallel with the treatment of platelet-rich plasma. Ketorolac, on the contrary, suppresses platelet activation. And, consequently, its use in parallel with platelet plasma treatment can reduce its therapeutic regenerative effect.

Displaced abomasum in cattle is a fairly common pathology, which occurs at different times after calving cows. According to the domestic authors, displaced abomasum in cattle at the dairy farming occurs in 1.5- 7% of the livestock. The domestic literature on treating displaced abomasum in dairy cattle provides limited and homogenous information on post-operative complications. The study was conducted for 4 years on 163 cows with a left-displaced abomasum or right-displaced abomasum that was repositioned and fixed in place with an incision in the right paralumbar fossa. The work took place on one of the farms in the Leningrad region. Native Holsteins of the domestic breed were kept untied in conditions of dairy complex. The total herd size is 1200 cows. Average cow milk production in the last 4 years was 11250 kg per year. During 4 years 163 cows with an operated displaced abomasum were clinically observed for the development of possible postoperative complications. The observation showed that 17 cows (10.42% of the operated animals) had postoperative complications in this period of time. Eight animals have developed purulent inflammatory complications diagnosed 20- 45 days after surgery. Three cows were found to have abscesses within 7-10 days of surgery. Hematoma was discovered in one cow 4 days after surgery. Four animals (2.45%) had a displaced abomasum’s reoccurrence among 163 cows in four years of observation.

The immunostimulating activity of betulin is manifested in the ability to induce the production of endogenous interferon in the body, as well as to increase cellular and humoral immunity, enhance the activity of some immunocompetent cells, in particular activating all indicators of phagocytosis (the ability of phagocytes to destroy viruses and bacterial cells). The purpose of the study is to study the effect of betulin on the clinical status and hematological indicators of breeding calves. The studies were conducted in the dairy complexes of the breeding farm of the Agricultural Enterprise Kolkhoz "Soznatelny", Zubtsovsky District, Tver Region, on the basis of the Department of Disease Diagnostics, Therapy, Obstetrics and Reproduction of Animals and the Treatment and Diagnostic Center of the Federal State Budgetary Educational Institution of Higher Education Moscow State Academy of Veterinary Medicine and Biotechnology - Moscow State Academy of Veterinary Medicine named after K.I. Skryabin (hereinafter referred to as the PH). Betulin was given to each animal of the group orally at a dose of 10 mg / kg of weight with water individually 1 time per day for 14 days. To assess the effect of betulin on the body of experimental animals, as well as to exclude concomitant diseases, a clinical study of all experimental animals and a hematological analysis were conducted at the beginning and end of the experiment. An automatic hematological analyzer Abacus Junior Vet (Austria) was used to conduct clinical blood tests. The number of erythrocytes, leukocytes, platelets, lymphocytes, basophils, monocytes, eosinophils, segmented neutrophils was calculated, as well as the hemoglobin level, color index, anisocytosis index, and hematocrit value were determined. The results of the effect of betulin on hematological indices of five-month-old breeding calves showed that the preparation causes a reliable increase in the number of peripheral blood lymphocytes (p≤0.01), eliminates the phenomenon of neutrophilic leukocytosis, reducing the number of neutrophils (p≤0.05) and the total number of leukocytes (p≤0.01) to the physiological norm. Thus, it can be assumed that the drug "Betulin" stimulates active reproduction of lymphocytes, enhances phagocytosis, which leads to the relief of the inflammatory process and a decrease in the number of neutrophils.