The purpose of research is to study the effect of the probiotic Profort-T on the composition of the rumen microbiome of dairy cows using NGS sequencing, productivity and hematological parameters of the animals' blood serum. The experiment was carried out on black-and-white cows for 60 days. Analogue groups of 20 animals each were formed: control group I (received the basic diet (BD)) and experimental group II (received the BD diet and the Profort-T probiotic). The BD consisted of: silage – 42.26 kg; hay – 1.97; mixed feed – 14.67 kg; salt, chalk, soda. The cows of experimental group II received the probiotic Profort-T at the rate of 0.03 kg per 1 head from the day of admission to the new calving group. The feed additive was distributed manually to each head of experimental group II during the new calving period and partially during milking. The animals were kept under the same conditions. Animals are kept in tethered conditions. The rumen bacterial community was assessed by NGS sequencing using a MiSeq sequencer (Illumina, Inc., USA). The use of a probiotic (experimental group II) made it possible to increase the average daily milk yield from 14.9 to 22.0 % compared to the control (P ≤ 0.05) and reduce the content of somatic cells in cows’ milk from 21.6 to 33.5 % (P ≤ 0.05). NGS sequencing demonstrated that 21 phyla of microorga¬nisms were found in the rumen microflora of the studied cows. The most represented (P ≤ 0.05) bacteria in the rumen were bacteria of the phylum Bacteroidetes – from 46.6 ± 4.48 to 58.1 ± 5.52 %. The proportion of cellulolytic bacteria Candidatus Saccharibacteria increased in experimental group II at the end of the experiment compared to the control by 1.9 times (P ≤ 0.05). Microorganisms Proteobacteria and Fusobacteria decreased in experimental group II compared to the control by 5.7 and 1.8 times, respectively (P ≤ 0.05), i.e. the use of the Profort-T probiotic led to an improvement in the structure of the microbial community of the cow rumen.

Abstract. Understanding the relationships between the microbiome of the digestive system, the use of probiotic supplements and zootechnical indicators in cows is the key to developing new strategies to increase milk yields. Purpose of research to study the composition of the microflora of the digestive system chyme and dairy productivity of cows under the influence of a complex biological preparation. Research methods. The experiment was carried out on of cows of black-and-white holsteinized. Groups were formed: control group I (who received the main ration (MR)) and experimental group II (who received MR and the “AntiKlos” feed additive). The bacterial community of the scar was evaluated by NGS-sequencing, the intestinal microflora, litter and feed were evaluated using real-time PCR. Results showed that the use of the “AntiKlos” feed additive on livestock allowed to increase the average daily milk yield to 7.5 kg compared with control I (P = 0.05). The bacteria Bacteroidetes were the most abundantly represented (P ≤ 0.05) in the rumen – from 20.9 ± 4.36 and up to 55.3 ± 6.74 %. It was shown for the first time that under the influence of the introduction of the “AntiKlos” feed additive into the diet, there was also a 16.1-fold decrease in Fusobacteria phylum bacteria in experimental group II compared with control I (P < 0.05). In addition, the use of the “AntiKlos” feed additive led to the complete disappearance of such species as Streptococcus caprae, S. didelphis, Mycoplasma conjunctivae in the rumen, among which opportunistic and pathogenic forms are often found, which is the scientific novelty of the study. Similar bacterial taxa were found in the food from the feed table, litter and rectum of almost all the dairy cows studied. In the rectal chyme of cows of the experimental group, the number of taxa such as Clostridium spp., Enterobacteriaceae and Staphylococcus spp. decreased in comparison with control I (P ≤ 0.05). Thus it is necessary to pay attention to increasing the efficiency of animal husbandry by regulating the microbiomes of cows, as well as the microflora of feed and housing sites.

Relevance. The broad use of antimicrobials by agriculture and consumers motivation to buy antibiotic-free production form a basis to development of substitutes to antimicrobials. The goal of research was the analysis of antimicrobial resistance caused by veterinary antimicrobials administration to broilers, as well as the effect of metaprobiotic “Probiocid-Ultra” on antimicrobial resistance in dynamic.Methods. Three groups of broiler chickens were formed: I — control, who received the main diet, II — experimental, who received veterinary antibiotics enrofloxacin and colistin in addition to the diet of group I, III — experimental, who received the metaprobiotic “Probiocide-Ultra” in addition to the diet of group II. Gene expression analysis was performed using quantitative reverse transcription PCR. With inoculation to different media the antimicrobial resistance was examined with classical microbiological methods.Results. The dynamic of accumulation of antimicrobial resistance determinants caused by enrofloxacin and colistin administration to broilers was examined. Under the influence of enrofloxacin the increase in antimicrobial resistance to enrofloxacin itself, as well as to beta-lactams, tetracycline and colistin was observed. Under the influence of colistin the increase in antimicrobial resistance to colistin itself, as well as to enrofloxacin and beta-lactams was observed. The feed administration with metaprobiotic “Probiocid-Ultra” promoted noticeable decrease of the antimicrobial resistance genes amount, when analyzed with growth medium led to antimicrobial resistant enterobacteria vanished.

To evaluate the effects of antibiotics and glyphosate, an experiment was conducted on 260 broilers. Four experimental groups were formed: I—control group, which received the basic diet (BD), II experimental group—BD with the addition of glyphosate; III experimental—OR with the addition of glyphosate and veterinary antibiotics enrofloxacin and colistin methanesulfonate; IV experimental—OR with the addition of glyphosate and ammonium maduramicin. Glyphosate and antibiotics combined with a herbicide altered the microbial community in broiler’s cecum. Genome-wide analysis made it possible to estimate the increase in the proportion of eukaryotic microorganisms and viruses under the influence of antibiotics. In the group of prokaryotic microorganisms, under the influence of glyphosate and antibiotics, significant changes were noted associated with a decrease in the proportion of bacteria, such as Faecalibacterium sp., Lawsonibacter sp., Lachnoclostridium sp. and Subdoligranulum sp., capable of producing butyrate and other short-chain fatty acids. These results indicate the negative impact of glyphosate in combination with antibiotics on the health and productivity of poultry, since these acids have a wide range of positive properties, for example, bacteriostatic, anti-inflammatory and proliferative effects.

Relevance. The intensin’s microbiota plays a crucial role in feed digestion and nutrient digestion in farm poultry, influencing zootechnical performance.The aim of the study was to compare the effect of the addition of lysine and methionine in various forms to the diet on the composition of the intestinal microflora of chickens and roosters of the «Smena 9» cross, as well as to establish a connection between the composition of microflora in different diets with the zootechnical indicators of birds.Methods. Physiological reseach were carried out on meat chickens of the Plimutrock breed and roosters of the Cornish breed of the parent herd of the domestic cross “Smena 9” selection of the “Smena” SSC. 4 groups were formed (control 1A and experimental 2A-4A) such as of 9 laying heads and 4 groups of 9 rooster heads (control 1B and experimental 2B-4B). Analysis of samples of the contents of blind processes of the intestine of birds was carried out by PCR.Results. As shown by the quantitative PCR method, the studied feeding factors: various sources of lysine and methionine and a 5% reduced level of metabolic energy of feed had a different effect on the composition of the microflora of chickens and roosters of the parent stock of the new cross «Smena 9». For example, with a decrease in the level of metabolic energy in the diets of chickens, there was a decrease from 1.2 to 5.0 times in such representatives of the normoflora as Bacteroidetes and Eubacteriaceae, compared with similar groups with a basic amount of metabolic energy (p < 0.05). When lysine was introduced into the diet in the form of monochlorohydrate and DL-methionine, a decrease in the weight of ovaries with an oviduct by 6.9 g was noted against the background of a decrease in the level of metabolic energy compared with the corresponding group with a base content of metabolic energy (p ≤ 0.05), whereas when using lysine in the form of sulfate and methionine in the form of a hydroxyanalog of methionine, a similar effect was reduced not noted (p > 0.05). At the same time, shifts in the composition of microflora against the background of changes in diets did not have any connection with the studied zootechnical parameters in chickens and roosters.

Применение пробиотиков позволяет нормализовать состав микрофлоры и снизить патогенную нагрузку в рубце, что приводит к улучшению зоотехнических показателей коров. Эксперимент проводили на 2 группах дойных коров в течение 90 суток. Животные контрольной группы получали основной рацион (ОР), а опытной — ОР и испытуемую кормовую добавку на основе штамма микроорганизма Bacillus sp. и органических кислот. При скармливании дойным коровам кормовой добавки отмечено увеличение, в среднем за опыт, среднесуточного удоя молока 4%-ной жирности на 2,3 кг и снижение содержания соматических клеток в молоке на 60% (P≤0,05). Результаты, полученные методом T-RFLP, показали, что важным эффектом от действия препарата явилось уменьшение в рубце числа клостридий на 4,4% по сравнению с контролем (Р≤0,05). Также в опытной группе наблюдалось увеличение содержания целлюлозолитических бактерий — лахноспир и руминококков в 1,5 и 4,2 раза соответственно по сравнению с контролем (P≤0,05). The use of probiotics allows to normalize the composition of microflora and reduce pathogenic microorganisms in the rumen, which leads to zootechnical indicators of cows improvement. The experiment was carried out on 2 groups of dairy cows for 90 days. Animals in the control group received the basic diet (BD), while the animals in the experimental group received the BD and a tested feed additive based on the strain Bacillus sp. and organic acids. When dairy cows were fed the feed additive, the average daily milk yield of 4% fat milk increased by 2.3 kg and somatic cell content in milk decreased by 60% (P≤0.05). The results obtained by the T-RFLP method showed that a significant effect of the probiotic was a 4.4% decrease in the number of clostridia in the rumen compared to the control group (P≤0.05). Additionally, an increase in cellulolytic bacteria — Lachnospira and Ruminococcus by 1.5 and 4.2 fold, respectively, was observed in the experimental group compared to the control (P≤0.05).

Here, samples to identify bacterial endotoxins were collected from two commercial dairy farms in Leningrad Oblast: farm A (samples of feces and milk were taken) and farm (where samples were taken from the feeding table, milk and rumen chyme). The study comprised four groups (A1, A2, B1, B2) where 1 was the control and 2 the test group. A1 were healthy, A2 showed signs of pathologies of the limb joints, B1 received the basic diet (BD) and B2 were fed this, plus the feed additive AntiKlos. Using PCR, samples were examined for the presence of genes for Shiga toxins (stx1A, stx2B), intimin (eae) and enterohemolysin (ehxA) produced by enterobacteria; for alpha (cpa1), beta (cpb) and epsilon toxin (etx) produced by Clostridium perfringens, plus binary toxin (cdtB), toxin A (tcdA) and toxin B (tcdB) produced by Cl. difficile. In the test Group A2, one animal out of six studied (16.7

In conditions of intensive poultry farming, significant amounts of xenobiotics enter the bird’s body. To investigate this, four groups of Ross 308 broiler chickens were formed: (1) control group fed the basic diet (BD); (2) experimental group fed BD supplemented with glyphosate; (3) experimental group fed BD along with combination of glyphosate and two antibiotics, enrofloxacin and colistin methanesulfonate. Analysis of the expression of genes for performance (IGF1, IGF2, MYOG, MYOZ2, SLC2A1, SLC2A2, SLC5A1, MSTN and TGFB1), antioxidant defense (CAT, SOD1, PRDX6 and HMOX1) and histological barrier function (MUC2, OCLN and CLDN1) in cecal tissues of birds were carried out using quantitative RT-PCR using a DTlight thermal cycler (DNA-Technology, Russia) and the SsoAdvancedTM Universal SYBR® Green Supermix kit (Bio-Rad, USA). The results showed that glyphosate alone (Group 2) inhibited the expression of a number of genes associated with productivity (IGF1, IGF2, SLC5A1 and MSTN) up to 4.1 times as compared with Group 1 (p < 0.05). In Groups 2 and 3, there was a decrease in almost all cases in the mRNA production of the MUC2, OCLN and CLDN1 genes in intestinal tissues from 1.3 to 2.2 times as compared to the control (p < 0.05).

In cows, there is a drastic metabolic stress caused by violations of the rumen microbiome composition during lactation. The aim of the present study was to investigate the α-and β-diversity of the rumen microbiome of lactating cows using next-generation sequencing (NGS) and gene expression assessed by qPCR, as well as evaluation of the corrective properties of a probiotic strain introduced into the rumen. The results showed that the addition of the probiotic to the diet contributed to an effective increase in the fat content of milk during the early lactation period (P ≤ 0.05). The NGS-based analysis of the rumen microbiome of the studied cows using the 16S rRNA gene sequences showed that the Shannon and Chao1 indices of α-diversity of prokaryotic communities remained unchanged during various feeding phases, as well as due to the probiotic effects. In the early lactation period and under the probiotic's impact, the number of representatives of the Clostridia_UCG-014 and Clostridiaceae families declined by 2.4 and 1.6 times, respectively (in Group 2 as compared to Group 1, P ≤ 0.05). Expression of the bacterial Ldh-L and ldhD genes was lower by 2.9 and 13.5 times, respectively (P ≤ 0.05), when adding the probiotic to the diet in the early lactation period.

In recent years, there have been more data that the nonselective herbicide glyphosate (GLY) can negatively impact gut bacterial communities. The aim of our study was to investigate the composition of broiler caecal microbiome under chronic exposure to GLY and the introduction of a probiotic microorganism strain into the diet. 120 broilers were divided into three groups: Group 1 of control birds fed the basic diet (BD); Group 2 of experimental birds fed BD supplemented with GLY; and Group 3 of experimental birds fed BD supplemented with GLY and a probiotic strain of the microorganism Bacillus sp. GL-8. For analysis, we used the next-generation sequencing (NGS) technique. Due to the GLY administration, there was a trend of lowering the biodiversity of normal microflora representatives, along with intestinal colonization by undesirable forms of microorganisms. In particular, when adding GLY (Group 2), we observed a decreased number of Tepidimicrobium representatives (0.001 ± 0.00006

Relevance. There is increasing information that glyphosates can have a range of adverse effects on animal, bird and human health, raising serious concerns about global feed and animal and poultry product safety. Methods. The experiments were carried out in the vivarium of OOO “BIOTROF+” on broilers of the Ross 308 cross. The birds were divided into 3 groups: 1st (control), which received a diet without additives, 2nd (experimental), which received a diet with the addition of glyphosate, 3rd (experimental), which received a diet with the addition of glyphosate and a strain of the microorganism Bacillus sp. GL-8. Analysis of the gene expression of the caecum of the intestines of broilers was carried out using quantitative PCR with reverse transcription. To analyze mRNA expression, specific primers for antimicrobial peptide genes were selected. Amplification reactions were performed using “SsoAdvanced™ Universal SYBR® Green Supermix” (“Bio-Rad”). Results showed that the residual amounts of glyphosates which are present at sterns of broilers influence an expression of genes of antimicrobic peptides AvBD1, AvBD2, AvBD4, AvBD6, CATH-2, NK-lysin, strengthening it. For example, in experimental group 2, there was an increase in gene expression of defensins AvBD1, AvBD2, AvBD4, AvBD6 by 21.9, 29.9, 35.1 and 33.5 times, respectively, compared to control group 1 (Р ≤ 0,001). A decrease (31 to 41%) in LEAP-2 gene expression when feed is contaminated with glyphosates may likely lead to a decrease in resistance to bacterial pathogens such as Salmonella enterica typhimurium, Streptococcus spp. and increased severity by the symptom of coccidiosis in poulty. The probiotic had a «leveling» effect on the expression of AvBD1, AvBD2, AvBD4 and AvBD6 defensin genes. This is likely due to the enhancement in the probiotic-modified gut microbiota of glyphosate metabolic opportunities, which may have acted as a physical barrier.

Relevance. Dependence on fishmeal hinders the development of the poultry industry. The aim of the study was to analyze the expression of key genes in the parent stock of Gallus gallus L. lines CM5 and CM9 of the meat cross «Smena 9» on the background of diets with the replacement of fish meal. Methods. Experiments were carried out on CM5 and CM9 chickens: groups 1A and 1B received the main diet (MD), 2A and 2B — MD with the replacement of fish meal with soy products, 3A and 3B — MD with the replacement of fish meal with sunflower products, 4A and 4B — MD with the replacement of fishmeal with soybean and sunflower products at a ratio of 50:50. Gene expression analysis was performed using quantitative reverse transcription PCR. Results. The most pronounced changes in the levels of expression of key genes against the background of the replacement of fishmeal with soybean and sunflower processed products concerned the maternal line Plymouth Rock CM9 compared to the paternal line Cornish CM5. Thus, the expression of SOD mRNA in groups 2B, 3B and 4B decreased by 14.3–100 times compared with control 1B ( р ≤ 0.05). Whereas in the experiment on the CM5 line, the expression of the SOD gene in the experimental groups 2A and 3A decreased by no more than 3.5 times compared with the control 1A ( р ≤ 0.05). In all experimental groups, zootechnical indicators of meat and egg productivity were noted at the level of control groups ( р > 0.05).

Abstract. An unsatisfactory microclimate in poultry premises contributes to damage in the form of a decrease in the average daily gain of broilers by 10 %. Purpose of research is to study the effect of relative humidity at the same temperature regime on the immunity and productivity of broilers of the Ross-308. Research methods. The experiment was carried out on broiler chickens of the cross Ross-308 up to 35 days of age. In group II, period 0–1 days of growing broilers, the relative humidity indicators were less than the lower limit of the norm by 10 %, in periods 5–7, 11–16, 20–22 and 26–35 days, the relative humidity indicators were less than the lower limit of the norm by 5 %. In group I, all indicators were recommended as recommended. The bactericidal activity of blood serum was determined by the method of I. M. Karput, lysozyme activity was determined by the nephelometric method according to V. G. Dorofeychuk. Results. As a result of the study, it was found that a decrease in the change in relative air humidity had a negative effect on immunity: the bactericidal and lysozyme activity of blood serum decreased. So, on the 21st day, the indicator of bactericidal activity of blood serum of broiler chickens in group II was lower by 14.2 % (P ≤ 0.05) compared to group I. At 3 weeks of age, the lysozyme activity of the blood serum of chickens of group II was lower by 14.3 % (P ≤ 0.05) compared to the control group. The productivity of birds also decreased to 13.70 % in relation to the control. Scientific novelty. For the first time, we have shown that a decrease in the indicators of relative air humidity at the content of Ross-308 cross broilers during the period of 0–1 days of cultivation by 10 % relative to the lower limit of the norm, during the periods of 5–7, 11–16, 20–22 and 26–35 days – by 5 %, subject to the recommended temperature parameters, has a negative effect on immunity.

Although the herbicide glyphosate is widely used globally and considered safe, more evidence of its adverse effects on animals and humans is accumulating. The present investigation was aimed at evaluating the impact of different glyphosate concentrations on zootechnical characteristics and clinical, biochemical and immunological blood parameters in Ross 308 broiler chickens. Four groups were employed, including untreated control and three experimental groups fed diets enriched with glyphosate at doses of 10, 20 and 100 ppm that conformed to 0.5, 1 and 5 maximum residue limits, respectively. The results showed that glyphosate is a stress factor triggering a multifaceted effect on important blood parameters (e.g., white blood cell and phagocytic counts), which was shown for the first time in the experiments involving productive meat-type poultry. It was first revealed that glyphosate-induced changes in blood parameters may be related to a negative impact on the zootechnical characteristics including the digestive tract organ development and body weight gain. The study findings suggested that exposure to glyphosate in the feedstuffs can adversely affect the physiological condition and productivity of broilers.

Glyphosate is the most common and widely used broad-spectrum herbicide. Although glyphosates are generally considered harmless to animals, they can affect macroorganisms through changes in microbial communities: glyphosate sensitive. In the present study, the toxic effect of glyphosate on the composition and functional state of the caecum microbiome of broiler chickens was assessed using the whole genome sequencing method. Functional differences in the microbiome that occur in the microbial community under the influence of glyphosate were identified at the level of glycolytic enzymes of the pathways responsible for the metabolism of simple carbohydrates. Elimination of a number of enzyme genes involved in the Embden-Meyerhof pathway was revealed. When glyphosate was added to the poultry diet at a concentration above the MPC, phosphodiesterases were eliminated in the microbial community, so glyphosate can lead to an increase in the concentration of second messengers (for example, cAMP) and disruption of signaling between cells. In the microbiome of the experimental birds, the decrease in diversity occurred inversely with the concentration of glyphosate. Such changes can indirectly lead to a decrease in the efficiency of the digestive processes of digestion of feed by birds and a decrease in the level of energy metabolism.

Silage is one of the most common feedstuffs used in modern dairy and beef farms, but silage quality is often measured without assessing the presence of pathogens. However, poorly prepared or contaminated silage can contain pathogens that reduce animal performance, cause bovine disease, and pose a threat to human health. The aim of this study was to analyse changes in the diversity of the silage microbial community during the ensiling process and to evaluate the effectiveness of two strains of promising microorganisms for use as inoculants. As a result of the study, it was shown that epiphytic microbiota has less potential to rapidly create and, most importantly, maintain high acidity conditions. The highest proportion of lactic acid bacteria was found in the variants with the introduction of strains of Lactobacillus plantarum and Bacillus subtilis at almost all stages of ensiling, indicating that the ensiling process was proceeding correctly in these variants. The lowest number of bacteria belonging to the Enterobacteriaceae family was found in the variant with the L. plantarum strain. Some microorganisms were detected in the silage, including mammalian pathogens: representatives of the genera Staphylococcus, Erysipelothrix, and Fusobacterium.

Background. Feed-borne T-2 toxin may inhibit innate immune system function in birds.The aim. To evaluate the effect of T-2 toxin, artificially introduced with feed, on the expression level of a number of immunity-related genes in the tissues of the broiler digestive system.Materials and methods. The experiments were carried out in the vivarium of the FSC “VNITIP” RAS broilers of the Smena 8 cross from 33 to 47-day old. Experimental contamination of feed T-2 toxin was performed. The birds were divided into 4 groups of 5 animals each: I – control, receiving a diet without the introduction of T-2 toxin, II experimental – receiving a diet with the addition of T-2 toxin, III experimental – receiving a diet with the addition of T-2 toxin and the sorbent Zaslon2+, IV experimental – receiving a diet with the addition of T-2 toxin, the same sorbent Zaslon2+and Axtra Pro enzyme. The level of mRNA expression was analyzed by quantitative reverse transcription PCR.Results. The data obtained indicated the impact of T-2 toxin contamination of broiler feed on the modulation of the level of expression of genes associated with the functioning of the immune system in the cecum and pancreas. Exposure to T-2 toxin (group II) led to an increase in the expression of the pro-inflammatory gene IL-6 in the tissues of the caecum by 10.8 times and IL-8 in the pancreas by 3.89 times (p ≤ 0.05) compared with control group I. The effect of the sorbent, as well as the complex, including the sorbent and the enzyme, on the expression of broiler genes was positive. The sorbent without the enzyme showed greater efficiency than with the additional introduction of the enzyme.

The search and development of natural biological additives that have a comprehensive effect as immunostimulants and improve digestion in poultry is relevant. This study was carried out at the Selection and Genetics Center “Zagorskoe EPH”. The control and experimental groups were formed of the 1-day-old Ross-308 cross broilers (35 heads in each). Six groups were formed. The broilers of the group No.1 (control) received basic feed (BF) with the addition of feed antibiotic Maxus. The group No.2 (control) received BF without feed antibiotic. The broilers of the group No.3 (experimental) received BF and the KH-1 chitosan complex. The group No.4 (experimental) received BF and the KHM chitosan complex with the addition of copper nanoparticles. The group No.5 (experimental) received BF and drinking preparation based on the KH-Aqua chitosan complex. The group No.6 (experimental) received BF and drinking preparation based on the KH-Aqua chitosan complex enriched with copper nanoparticles. The bacterial community of the gut cecum was analyzed using the molecular genetics method of next-generation sequencing (NGS). The addition of chitosan complexes (both supplemented with copper nanoparticles and in the drinking form) made it possible to obtain high livability of broilers with increased live body weight and decreased feed consumption per 1 kg of live body weight gain. The live body weight of 35-day-old broilers in the experimental groups was 2.96-5.70% higher than that of the control with a 5.86-8.23% decrease in feed consumption per 1 kg of live body weight gain. The results of NGS showed that the effect of chitosan complexes on the regulation of the composition of the microbiome of broilers’ cecum was predominantly positive. There was an up to 4.4-fold increase in the content of representatives of the normoflora, bacteria of the family Lactobacillaceae. The number of bacteria of genus Helicobacter, among which pathogens are often found, in the experimental groups was 2.6-33.3 times lower than in the group received antibiotics. So, the chitosan complexes were proved to be valuable supplements for poultry.

The adaptive ability of reindeer to the harsh conditions of the Russian Arctic is not determined solely by the genome of the macroorganism and, of course, includes an extensive genetic and metabolic repertoire of the microbiome. The aim. To compare the taxonomic and predicted metabolic profiles of the rumen microbiome of adult reindeer living in the natural pastures of the Yamalo-Nenets and Nenets Autonomous districts of the Russian Federation. Materials and methods. Expeditions to the Yamal-Nenets and Nenets Autonomous districts of the Russian Arctic in 2017 were carried out to take samples of the rumen. The contents of the rumen were taken from clinically healthy reindeer individuals (at least 3 times repetition). To analyze the animal scar microbiota and determine metabolic profiles, 16S rRNA NGS sequencing was performed on a MiSeq device (Illumina, USA). Bioinformatic data analysis was performed using QIIME2 software ver. 2020.8. The noise sequences were filtered by DADA2. Silva 138 reference database was used for taxonomy analysis. Reconstruction and prediction of the functional content of the metagenome was carried out using the software complex PICRUSt2 (v. 2.3.0). Results. During NGS sequencing, a total of 223 768 sequences of the 16S rRNA gene of the reindeer scarring microbiome were studied. Significant (p ≤ 0.05) differences between the groups in 10 bacterial phyla and superphyla were revealed: Actinobacteriota, Spirochaetes, Chloroflexi, Verrucomicrobia, Bdellovibrionota, Synergistetes, Fusobacteriota, Myxococcota, Cyanobacteria, Campilobacterota. The results of the reconstruction and prediction of the functional content of the metagenome using the PICRUSt2 bioinformatic analysis made it possible to identify 328 potential metabolic pathways. Differences between the groups were revealed in 16 predicted metabolic pathways, among which the pathways of chlorophyllide and amino acid biosynthesis dominated.