Guinea fowl is a relatively new sub-branch of poultry farming, which provides the population with dietary products — eggs and meat. However, even small enterprises are faced with the task of increasing the safety and productivity of an individual, since this type of bird has one of the most expensive prices. Reducing the risk of increased mortality directly depends on the level of resistance of the organism, the implementation of its immunity, 70% of which, as we know, depends on the health of intestines.  Therefore, the use of organic acids to improve performance is a relevant and effective way to reduce pathogenic microflora in the intestine, activate useful, normalize digestibility and, consequently, provide good growth and development of the body. The above studies were carried out according to generally accepted methods. As a result, it was found that the use of “Prodactiv Acid SE” in growing guinea fowls promotes an increase in safety, and also improves the dynamics of growth of live weight relative to the control group. 

 The article presents the results of a study of Oxymethyluracil effect on toxic liver damage with carbon tetrachloride. As a result of the induced toxic hepatitis in laboratory rats, a malfunction of the free radical lipid oxidation system is observed: the content of diene conjugates increases by 1.93 times and malondialdehyde — by 1.8 times in the blood serum compared to the intact group. There is a change in the indicators of liver pigmentation: the indicators of total bilirubin increased by 3.06 times, direct bilirubin — by 5.63 times, indirect bilirubin — by 2.8 times compared to the control group. After therapy with Legalon and Oxymethyluracil lipid peroxidation is inhibited and the antioxidant status of the body increases, and bilirubin indicators improve. When comparing the hepatoprotective properties of drugs in conditions of liver damage with carbon tetrachloride, the use of Oxymethyluracil is less effective than Legalon. 

 Pathological diagnostics is a mandatory and one of the most important methods for diagnosing animal diseases. Competent use of the methods of pathological and histological diagnostics allows in the shortest possible time to make the correct preliminary diagnosis, to carry out complicating diseases, and additional laboratory tests in a timely manner. At the same time, the pathological and morphological changes in the body of animals with a new zoonotic disease, COVID-19, have not been sufficiently studied or are not studied at all. This paper describes the pathological processes and histological changes in maine coon kittens with spontaneous SARSCoV-2  coronavirus infection. The obtained research results are presented in the  form of detailed pathological and histological diagnoses. It has been established that the leading structural changes in kittens’ bodies are characterized by the development of congenital and postnatal malnutrition, the predominance of profound disorders of the respiratory and cardiovascular systems: alveolar emphysema of the anterior and middle lobes of the lungs with areas of atelectasis and small focal interstitial  pneumonia in them, atelectasis of the caudal lobes of the lungs (in kittens 1–2 days of age); alveolar emphysema, edema (“carmine lungs”) of the lungs, large-focal interstitial pneumonia, sclerotization of the lungs with localization in the diaphragmatic lobes (at 10–14 days of age); acute expansion of the heart; acute venous hyperemia and edema of internal organs; pronounced postmortem blood coagulation in the cavities of the heart, large arteries and veins. Complicating processes are granular and small-droplet fatty degeneration of parenchymal organs, the development of which, apparently, is  due to a combination of hemodynamic disturbances, prolonged hypoxia and intoxication of the animal body. Considering the severity and depth of structural disorders, primarily in the lungs of newborn animals, it can be concluded that the kittens are infected vertically (transplacentally). 

 Relevance. Rabbit haemorrhagic disease virus type 2 (RHDV-2, GI2,) was first detected in 2010 in France and quickly spread across еuropean countries. Unlike strains of the first genogroup, RHDV GI2 also affects rabbits under 2 months old, as well as various types of hares. In addition, RHDV GI2 causes the death of rabbits vaccinated with vaccines based on type 1 hemorrhagic disease viruses. The rabbit hemorrhagic disease virus 2 (RHDV-2) was detected during an outbreak of the disease, characterized by the sudden death of rabbits of different age groups, in the summer of 2019 in a private farm in the Tula region, Russia.

The purpose of this study was to detect and obtain the molecular genetic characteristics of the pathogen.

Methods. The ELISA was used for the detection of RHDV antigen in samples of pathological material from dead animals. The presence of RHDV RNA was determined by the method of reverse transcription/polymerase chain reaction (RT/PCR) using pair of specific primers for the regions of the VP1 and VP60 genes. The Sanger sequencing reaction was performed and obtained nucleotide sequences were analyzed.

Results. Antigen and RNA of the rabbit haemorrhagic disease virus were detected by ELISA and RT-PCR in laboratory studies of the liver of dead animals. Analysis of the nucleotide sequence of a 470 base pair region of the genome, containing the 5 ‘terminal region of the VP1 gene and the 3’ terminal region of the VP60 gene, showed that the detected virus belongs to RHDV-2. Phylogenetic analysis revealed that the closest to it were the sequences of RHDV-2 from the USA, France and Poland isolated in the  2016–2020. The VP60 amino acid sequence of detected virus contained the A46T substitution (alanine for threonine at position 46), which can affect the conformation of the capsid protein and, as a consequence, the antigenic structure of the virus. 

 In animal feeding enzyme preparations are mainly used, which are not produced in the body of animals, although in chickens in the first weeks of life and piglets after weaning an insufficient amount of their own proteases and amylases is formed, so their inclusion in feed is also useful. By now highly active enzyme preparations with various specific activities have been created and are being produced. In feeds prepared using traditional raw materials up to 30% of nutrients are not available for digestion by enzymes secreted in the gastrointestinal tract. The inclusion of exogenous enzymes in the feed provides additional use of the indigestible fraction. It is impossible to achieve complete digestibility of feed, although in vitro exogenous enzymes digest almost 100% of the target substrates. The problem is due to the fact that natural feed does not contain pure substrates — they are associated with other substances that  limit the availability of enzymes to them. The properties of natural substrates, their concentration and availability even in the same raw material are variable, which excludes reliable prediction of the effectiveness of the action of feed enzymes. Partially these difficulties are overcomed by the use of polyenzyme drugs. It is necessary to further study the specificity of native substrates and factors that increase their availability for the action of enzymes. 

 Relevance. ZIGBIR® feed additive, consisting of a set of plants that affect the state and recovery of hepatocytes, is unique and is of interest for research. As a result of the experiment, the feasibility and effectiveness of using the plant feed additive ZIGBIR® in the diets of pregnant dry cows was studied. Its effect on the absorption of nutrients in the diet, biochemical parameters, the safety of young animals and gynecological diseases is shown.

Methods. The experimental part of the work was carried out in the Agricultural Cooperative “Named after Ilyich” of the Novgorod region on cows of the dry period. According to the principle of analogs, three groups of animals were formed — a control group and two experimental ones (n = 10 in each) from cows that were in the run taking into account the dates of the planned calving. The animals of the first experimental group, in addition to the main diet, received a feed additive ZIGBIR® in the amount of 20 g/head/day, the second experimental group — 25 g/head/day.

Results. As a result of scientific research, it was found that groups of cows that received a feed supplement in addition to the main diet were better able to absorb nutrients. So the coefficient of dry matter digestibility in the first experimental group increased by 0.9%, in the second — by 0.4%. A similar increase in the digestibility coefficients was observed for organic matter (by 1.7–8.3%), crude protein, crude fat, BEV and crude fiber. The introduction of the supplement into the diet did not lead to a deterioration in biochemical parameters. For example, the value of the protein index (the ratio of albumins to globulins), indicating the intensity of protein metabolism, in the control group was 0.66, and was below the physiological limit by 27%. However, in both experimental groups its indicators increased and almost returned to normal with values of 0.9 and 0.8 respectively. The reduction of postpartum pathologies and the increase in the safety of young animals suggests the therapeutic effectiveness of the ZIGBIR® feed additive. 

 The age structure of ontogenesis of cenopopulations of the valuable forage species Vicia crocea (Desf.) Fritsch of the Vicia L. genus was assessed, the dynamics of their development and viability were studied. Large number of generative individuals have been revealed at the study of age spectrum. The studied plants were well eaten by cattle during this period. The number of reproductive (generative) individuals and populations decreased in this case, as well as under the influence of other anthropogenic factors, and Vicia crocea (Desf.) Fritsch was classified as a specie belonging to the category “close to the danger threshold” (NT). The study of this species at the cenopopulation level have scientific and practical importance in terms of studying the species  composition of phytocenoses, increasing the fodder base of Azerbaijan, improving the condition of summer and winter pastures, enriching arable land with nitrogen, developing animal husbandry as an agricultural sector, as well as using fodder plants in various industries. 

 Relevance. The article provides a substantiation of the economic efficiency of the use of biologically active additives that improve the bioavailability of nutrients in compound feeds in the diets of meat-producing turkeys and increase the yield of competitive high-quality products. Among the most effective biogenic preparations that have a positive effect on metabolic processes in the body of poultry, there is a biogenic growth stimulator — succinic acid. The inclusion of this preparation in a complete feed at different age periods of growing turkey poults has a significant effect on the  feed intake and conversion.

Methods: scientific and economic experience on the use of succinic acid when growing turkeys.

Results. The article presents the results of a research to study the effect of adding succinic acid during the period of growing in feed on the indicators of meat productivity of turkey poults and thus increasing the efficiency of its production. It was found that the maximum slaughter yield for both half-gutted and gutted carcasses in group 2 turkeys that received 0.02 g/kg succinic acid was, respectively, 80.4% and 60.2%, which is 2.5% and 2.4% higher than in the control, respectively. In terms of meat productivity, poultry raised on the basis of the addition of succinic acid to feed has  advantages over the control group (without the use of the drug), as well as in biological and nutritional additional costs for succinic acid, the cost of meat in the experimental groups was lower than in the control due to higher productivity. 

 Тhe results of the research work of 2017–2020 on the influence of presowing seed treatment and non-root fertilization of plants on increasing the yield and quality of hemp products of the Nadezhda variety in order to improve the cultivation technology are presented. The results of the experiment show that the highest yield of stems (7.96–11.11 and 6.57–8.73 t/ha) was obtained in the most favorable years for weather conditions in 2017 and 2019, and the lowest — in 2020 (3.02–4.2 t/ha). Pre-treatment fertilizer Isagri Force increases the seed yield by 11.1–14.1%, and the fungicide TMTD, VSK — by 3,5–5,6%. The most responsive cannabis plants were to the interaction of the mordant, fertilizer and foliar top dressing of plants during the growing season, the increase in yield was 0.37 t/ha. 

 Relevance. The authors present the results of research on the study of the influence of new-generation growth regulators. One of the most important elements of modern agricultural technologies is the use of biological products and growth regulators of agricultural plants that can positively affect the metabolic processes in plants. The practical value of these drugs is determined, first of all, by their effect on the processes of plant development at different stages of ontogenesis and the ability to accelerate growth or increase productivity. The use of growth regulators is considered an environmentally friendly and cost-effective way to increase crop productivity, contributing to the fuller realization of the potential of winter wheat. The aim of our research was to improve the technology of winter wheat cultivation using Sapress growth regulators.

Methods. The experiments were laid on the experimental field of the SKNIIGPSH VNC RAN in 2018–2021. The soil of the experimental site is represented by leached chernozem with a close occurrence of pebbles, pH 5.7, humus content — 4.7%. The continental climate in this zone is 53. The average annual air temperature is + 8.4 °C, the average long-term sum of positive temperatures for the year is 3426 °C.

Results. As a result of the research, it was found that the growing conditions and varietal characteristics of winter wheat affect the value of all elements of the crop structure. The condition of winter wheat crops visually varied slightly in terms of growth and development, color intensity, by varieties and on all variants. The density of seedlings in the variants did not differ significantly. After the use of the growth regulator Sapress at a dose of 0.2 l/ha and 0.3 l/ha on different varieties of winter wheat during the growing season the plants differed in height, length of the ear, the number of grains  in one ear. Of the tested varieties, the most productive were the varieties Trio and Alekseich. It should be noted that the difference in the yield increases after non-root top dressing by the growth regulator between the varieties was insignificant, despite the fact that the growing season was 15–20 days longer. 

 Introduction. The initial material is the basis of the current breeding work with all agricultural crops, including alfalfa. The purpose of the conducted work is to estimate the productivity of alfalfa samples in the collection nursery, depending on the growing conditions and the identification of the most adapted samples according to the trait “green mass productivity”.

Materials. The objects of the current study were 30 alfalfa samples (16 samples from Canada; 11 samples from the USA; 1 sample from Peru; 2 samples from France) from the collection ARIGCR named after N.I. Vavilov.

Results. The estimation of alfalfa samples for the presence of adaptive properties based on the trait ‘green mass productivity’ showed that: — the genotypes К-27116, К-43269, К-43272, К-48771, К-48775, К-48776, К-50545, К-50561, К-45119 are more responsive to changes in environmental conditions; the genotypes К-32873, К-33299, К-42684, К-42249, К-47803 are characterized with a slight bi < 1 response to changes in environmental conditions; the genotypes К-36104, К-48778, К-42694, К-45715, К-47800, К-47801, К-47802, К-43260 are characterized with high stability to stresses; the genotypes К-43272, К-50545, К-47806, К-47807 are characterized with genetic adaptability; the genotypes К-36104, К-48778, К-48715, К-47800, К-43260 are characterized with more stability of response to changes in environmental conditions; the genotypes К-36104, К-48778, К-45715, К-47800, К-47801, К-47802, К-39978, К-43260 are characterized with great homeostasis (ecological adaptability). 

 Relevance. Establishment of regularities of growth and development, determination of the influence of the temperature factor on the individual phases of clematis ontogenesis for a reasonable prediction of the timing of their occurrence in the conditions of the Stavropol upland.

Methodology. The paper presents the results of studies of the onset of certain phases of growth and development of clematis varieties of the garden group Integrifolia in the Stavropol Botanical Garden. The data of phenological observations and meteorological indicators of 2016–2020 are analyzed.

Results. It is established that representatives of this group, in the climatic conditions of the Stavropol upland annually pass all stages of seasonal development. According to the results of long-term observations, the degree of adaptation to new natural and climatic conditions was revealed. The influence of the temperature factor on the dates of occurrence of phenological phases were analyzed. The weather conditions of the growing season cause the shift of the phenophases to earlier or later periods. In our studies, the dates of the onset of the “beginning of vegetation” phase vary,  due to the instability of meteorological conditions. The earliest date of the beginning of the growing season was marked on 04.03.2016, the latest — on 29.03.2019. The sum of active air temperatures above 0 °C for this period was 185–198 °C. The sum of effective temperatures above +5 °C required for the beginning of the budding and flowering phases has been determined. The duration of the interphase period from the beginning of the growing season to budding is on average 67 days. The interphase period from the beginning of budding to flowering is 18 days, the sum of effective  temperatures above +5 °C for this period was 220 °C. To predict the timing of the onset of the “flowering” phase, the necessary sum of effective temperatures above +5 °C for the interphase period from the beginning of the growing season to the beginning of flowering is calculated — 681 °C. The sum of the active temperatures above 0 °C, before flowering, was — 1212 °C. 

 The article presents the results of the multi-scale use of the Russian wildrye in the nursery of the source material and research on its nutritional value. The nursery of the source material was laid in 2015 by nesting method on the territory of the botanical garden “Research Institute of Agricultural Problems of Khakassia” in the amount of 26 samples. The work was carried out in accordance with the guidelines for the selection of perennial cereal grasses, selection and seed production of perennial grasses. Observations of the growth and development of plants, accounting of the productivity of the studied varieties were carried out on the selection of forage grasses in Siberia. When evaluating this culture for pasture use four mowing operatios were carried out. The characteristic value is not only the absolute value of the growth of the crop, but its relative stability of regrowth during the growing season. According to the sum of the four mows, the highest productivity of the green mass was observed in K 1, K 2, K 3, K 5, K 6, K 9, and K 18 — from 500 g to 720 g.The capacity of the grass stand after grazing is one of the indicators that determine the normal state and development of plants. After four — fold mowing, the numbers K 1, K 2, K 3, K 5, K 6, K 9, and K 18 had a high bush power-from 3.6 to 4.6 points. For the main mowing, forage units were allocated to 1, To 2 — 0,69 — 0,69 kg of feed standard 0.49 kg and at otave 0.68-0.67 kg, standard 0.49 kg, respectively, for digestible protein To 1-149.6, To 2 — 162.5 g / kg of feed standard 141.1 g/kg and to 1-147.2, to 2 — 140.2, standard 140.0 g/kg of feed) and for  exchange energy for the main mowing to 1 and 2 9.8 MJ and 10.0 MJ, standard (Manchaara) — 9.7 MJ. 

 Relevance. The aim of the work was to study the influence of predecessors cultivated in three crop rotations with a short rotation on the weedness of fiber flax crops and the yield of flax products. The study was carried out in field experiments in 2016–2019, on medium and weakly acidic soddy-podzolic light and medium loamy soils of the Tver region with a high phosphorus content.

Methods. As the precursors of fiber flax, vetch-oat mixture and white mustard were cultivated with post-cut cultivation of white mustard for green fertilization, and also repeated sowing of fiber flax was carried out in the same field for three years in a row after the predecessor of barley.

Results. As a result of the studies, it was found that the greatest lowering the weediness of fiber flax crops and an increase in the yield of flax products was observed in the crop rotation with the cultivation of white mustard for green fertilization after the precursor of the vetch-oat mixture for green fodder and the introduction of the biofungicide Sternifag after the precursor of barley with the addition of 12 kg/ha of ammonium nitrate. There was a decrease in the number of stems of couch grass (Agroperon repens) by 2.8 times, a significant increase in the yield of fiber flax — by 5 dt/ha a compared with repeated cultivation of fiber flax in the same field and by 1.4 dt/ha compared with cultivation after barley without the use of biofungicide. At the same time, the yield of flax straw was 29.1 dt/ha, of flax stock 22.4 dt/ha, of flax fiber — 6 dt/ha. In the crop rotation with the sowing of fiber flax after barley in the same field for three years in a row, there was a decrease in the yield of flax fiber by 0.3 and 0.8 dt/ha, including fiber scutched flax — by 1.6 and 1.7 dt/ha in comparison with cultivation in crop rotations with post-harvest use of white mustard for green fertilization. 

 The article presents research materials that are devoted to assessing the antideflationary effectiveness of the main field-protective forest plantations in the arid zone of the Stavropol Region.

Relevance. In the Stavropol Region the regional features of climate change are noted in the direction of increasing its aridity, which contributes to the increased likelihood of such phenomena as droughts, dry and dust storms. An important technique to reduce their harmful effects is the use of field-protective forest plantations, which were designed more than 40 years ago and are now significantly destroyed in many regions of Russia.

Methods. The originality of the research approach is the use of remote sensing and geoinformation technologies.

Results. On the study area an uncontrolled increase in arable land by 165.8 thousand hectares was revealed due to the plowing of hayfields and pastures, which led to a decrease in the protective forest cover of the territory to 3.6% with the recommended level of 3.8–4.8%. The average safety of protective forest plantations in the study area is 73%. The area of the main field-protective forest plantations is 36,733 hectares, with only 25% of them located at the recommended interband distances and 66% — at optimal angles relative to the prevailing winds. On the study area there was a decrease in the antideflationary efficiency of the main field-protective forest plantations to 78%, which extremely negatively affects the productivity of crops, especially if adverse events such as droughts, dry winds and dust storms occur. 

 Aim of the work was specific primers (FusA1F/FusA1R) testing to study the SE2 gene controlling acid chitinase effect under stress conditions. Plants of domestic and foreign sugar beet were the material for the investigation. To confirm relationship between the SE2 gene (localized to the chromosome 3) controlling steady effect of acid chitinase and sugar beet resistance to root rot, 10 sugar beet samples were genotyped using the FusA1 molecular marker. DNA-fragments of 600 and 400 b.p.in length were revealed in each of the investigated genotypes except plants of wild beet (Beta corolliflora Zoss.). As a result of molecular-genetic studies of the SE2 gene, eight single nucleotide polymorphism (3 T/C, 2 C/G, A/G, G/A, C/T) and 3 single nucleotide inserts (nucleotide A) were identified in plants of the breeding sample No. 9 (Sh.1). Plants of this genotype showed symptoms of fusariose infection under field conditions as well. It can be concluded that the SNPs data lead to overcoming of resistance (by changing an amino-acid unit in a polypeptide), and, as consequence, to decrease of plant adaptability. 

 Relevance. Chemical pesticides are currently used to protect potatoes from diseases. Their main advantage is efficiency, mass scale and speed. The main disadvantage is the dangerous to human life and warm-blooded animals toxic effect, as well as the death of beneficial insects (bees, bumblebees) pollinating plants. In addition, most harmful bacteria and fungi develop resistance to chemicals, forcing manufacturers to create new, increasingly toxic drugs. To solve this problem, it is of paramount importance to improve the technology of potato cultivation in the direction of its biologization, that is, the search for biological agents, the creation and use of biological agents on their basis for protecting potatoes and obtaining environmentally friendly products.

Methods. The aim of the study was to evaluate the growth-stimulating and antifungal action of bacteria of the genus Bacillus on potatoes of the Tuleyevsky variety. The results of field experiments are presented for the period 2019–2020. The experiments were conducted in the Novosibirsk region, g, Novosibirsk, UPH “Garden of Michurintsev” of the Novosibirsk State Agrarian University. To improve morphometric parameters and reduce the prevalence of rhizoctonia, potato tubers were treated with strains of the
bacterium of the genus Bacillus: B. thuringiensis ssp. morrisoni; B. thuringiensis ssp. dacota; B. subtilis; B. liheniformis. Phytosporin-M, P (B. subtilis strain 26 D) was used as a reference.

Results. The best results (on average for 2 years) were seen in the variant using the B. subtilis strain, which provided an increase in plant biomass by 1.7 (2019) and 1.2 (2020) times and the number of stolons by 43% compared to the control variant. The use of the strain B. thuringiensis spp. dacota in 2019 provided an increase in the length of the ground part by 10%, by 1.2 times-the number of stems and by 1.6 times — stolons. The prevalence of the causative agent of the black scab in all periods of accounting decreased by 1.7–3.7 times compared to the control in variant B. subtilis, and on the 10th week of accounting — in 3.5 (2019) — 2.6 (2020) times relative to the  standard. The use of bacterial strains allowed us to achieve a higher quality and higher yield compared to the control version and the standard. When using strains of B. thuringiensis ssp. morrisoni and B. thuringiensis ssp. dacota in 2019, the yield increased by 1.4 and 1.5 times, respectively, and in 2020, with the strains of B. subtilis and B. thuringiensis ssp. morrisoni — by 1.2 and 1.3 times respectively. 

 Relevance. Based on the materials of cadastral registration of unused land in the Zabaikalsky Region on an area of 1,010,033 hectares, their expert assessment was carried out for the meliorative state, economic suitability and land use conditions.

Methods. Satellite geocards, as well as photo and video reports of field sites obtained with the help of quadrocopters were used in the work.

Results. Drainage reclamation is required on an area of more than 77.0 thousand hectares. On an area of more than 900,0 thousand hectares it is necessary to carry out a complex of works on surface and agrotechnical land improvement. Complex land reclamation includes protection of floodplains and settlements from flooding, drainage of excessively wet areas, irrigation of crops, creation of antierosion protective forest stands.