A comparative analysis of concentration and inequality indicators of the publication activity of the “Agrarian science” journal for 2023-2024 is presented, based on data from the Russian Science Citation Index (RSCI) and eLibrary.ru (the scientific electronic library). The study focuses on the analysis of the Herfindahl — Hirschman indices (for citing journals and for author affiliations), the self-citation rate, and the Gini index.

The results indicate the journal’s stable position in the middle zones of the rankings for the fiveyear Herfindahl index (317 in 2023, 315 in 2024) and the self-citation rate (14.80 and 14.70, respectively), which meets the requirements of RSCI and the Higher Attestation Commission (VAK). The best results were recorded for the Herfindahl index by author affiliations (298 in 2023, 205 in 2024), where the journal is in the green zone, ranking among the top 25% of reference groups. The Gini index decreased from 0.70 to 0.66, indicating a trend towards a more equal distribution of article citations.

Based on the analysis, a development strategy for the «Agrarian Science» journal has been formulated, encompassing the modernization of editorial policy, attracting leading authors, and expanding international presence.

This paper presents the results of monitoring studies on anaerobic microorganisms, namely clostridia. Over a five-year period, 6372 samples of birds, pigs, and cattle (liver, intestines, stomach, lungs, muscle tissue, spleen, and heart) were examined using routine microbiological methods from such regions of Russia as Oryol, Tver, Novgorod, Nizhny Novgorod, Moscow, Kaluga, Chelyabinsk, Penza, Tambov, Volgograd, Kemerovo, Ryazan, Novosibirsk, Orenburg, Yaroslavl, Voronezh, Leningrad, Sverdlovsk, Rostov, Tyumen, Lipetsk, Tomsk, Vladimir, Omsk, Belgorod regions, Republics of North Ossetia — Alania, Bashkortostan, Tatarstan, Chuvashia, Mordovia, Buryatia, Perm, Altai, Krasnodar, Stavropol Territory, Moscow. As a result, 1060 clostridia isolates were obtained. According to the data obtained, the incidence of Clostridium tertium was 29.15%, Clostridium perfringens — 25.85%, Clostridium sporogenes — 11.89%, Paraclostridium bifermentans — 8.58%, Clostridium butyricum — 4.53%, Clostridium paraputrificum — 3.96%, Clostridium difficile — 3.02%, Clostridium cadaveris — 2.92%, Paeniclostridium sordelli — 2.26%, Clostridium novyi — 1.89%, Clostridium chauvoei — 1.42%, Clostridium sartagoforme and Clostridium spp. — 1.04%, Clostridium septicum and Clostridium baratii — 0.66%, Clostridium cochlearium — 0.57%, Clostridium ramosum — 0,28%, Clostridium sphenoides — 0,19%, Clostridium innocuum — 0,09%. Pathogenic properties were found in 165 isolates: 126 — Clostridium perfringens, 22 — Clostridium difficile, 7 — Clostridium novyi, 6 — Clostridium chauvoei, 3 — Clostridium septicum, 1 — Clostridium spp.; toxigenic properties were found in 105 isolates: 84 — Clostridium perfringens, 11 — Clostridium novyi, 6 — Paeniclostridium sordelli, 2 — Clostridium septicum, 1 — Clostridium difficile, 1 — Clostridium spp.

Escherichia coli is a component of the normal intestinal microbiota of humans and animals. Phenotypic and genotypic characteristics allow the identification of pathogenic E. coli strains. Numerous pathotypes, representing groups of strainswith specific pathogenic characteristics, have been described based on heterogeneous criteria. The use of whole-genome sequencing has led to the accumulation of genomic data that enable a population-phylogenetic approach to the emergence of virulence, thus allowing E. coli to be further classified into phylogenetic groups. An analysis of the literature data revealed that non-pathogenic E. coli living in the gastrointestinal tract of animals belong to group A, commensal and some pathogenic strains belong to group B1, InPEC belong to groups D1, D2 and E, most ExPEC belong to group B2, and strains that are phenotypically indistinguishable and genetically diverse, belong to Clade I. Emerging multidrug-resistant E. coli strains are more difficult to treat and pose a higher risk of bacteremia. Effective prevention and treatment of E. coli infections requires distinguishing between strains (pathotypes, phylogenetic groups) of the microorganism that cause disease in animals and strains that infect humans through the food chain, as animals serve as their reservoir. The development and implementation of effective preventive strategies requires a better understanding of the current taxonomy of the pathogen, as well as tracing its genomic evolution to generate fundamental knowledge for the development of not only effective vaccines but also new therapeutics to combat this diverse group of pathogens within the framework of a One Health approach.

The effect of probiotics “Enzymosporin” and Lactobacillus brevis 47f (LB 47f) was considered. Observations showed that the experimental test subjects demonstrated normal health indicators, without abnormalities in the functioning of the main body systems throughout the study. Morphometric parameters of the jejunum indicate that it is most developed in animals raised with the addition of probiotic LB47f to the feed, its total wall thickness is 1,676 microns, which is 19.09% more than in rabbits of the control group, and 8.7% more than in animals of the second experimental group. Thus, it can be concluded that in the jejunum of rabbits of the 2nd and 3rd experimental groups treated with probiotics, the processes of food digestion and assimilation of feed nutrients are more intense than in the control. The histological data obtained on the cecum at the end of the experiment allow us to judge the visible differences in the indicators of the experimental and control groups. The thickness of the mucous membrane in the 2nd group is 5.2% less than in the control, and in the 3rd group, on the contrary, it is 5.3% more (p ≤ 0.05). Morphometric parameters of the cecal wall of animals of both experimental groups indicate an increase in the submucosal layer relative to the control: by 39.2% in group 2 and by 21.4% in group 1. The thickness of the muscular membrane of the cecum in both experimental groups of rabbits was higher than the control: by 17.7% in group 2 and 0.9% in group 3.

Relevance. Differential diagnostic markers of intact polychromatophilic erythroblasts, mature erythrocytes and erythroblast ghosts, and erythrocyte ghosts in normal peripheral blood are presented in model organism of animals — birds (Aves).

Methods. Morphophysiological characterization of erythroblasts, erythrocytes and erythroblast shadows, and erythrocytes shadows was performed using blood smears of Gallus gallus L. birds (n = 40, stained with Pappenheim) from four age groups (Postembryonalis — P1, P7, P23, and P42: days 1, 7, 23, and 42 of postembryonic ontogenesis) of a industrial herd. Identification and cytophysiological analysis shadows profile nucleus, shadows profile cytoplasm, shadows profile cell, and unidentified cell shadows were performed using calibrated high-resolution micrographs (n = 158).

Results. In a model organism of animals — birds — morphological changes in erythroblasts in the peripheral bloodstream as a result of eryptosis have a cytophysiological character consistent with the status of a clinically healthy animal. Apoptotic changes in blast and cellular forms of the erythroid component in the peripheral bloodstream of birds are grouped into nucleocytoplasmic formations of varying severity, including: cytolysis, cytoplasmic fragmentation, karyopyknosis, karyorrhexis, karyolysis, chromatin fragmentation, chromatinolysis, and cytoplasmic vacuolization. The study of eryptosis in the peripheral bloodstream of birds resulted in the development and formulation of differential criteria – markers of erythroid cell shadows – with clinical, general biological and didactic significance.

Mitral valve endocardiosis is one of the most common heart diseases in dogs and poses a significant risk during dental surgery under general anesthesia.

The aim of the study was to evaluate the effectiveness of the pimobendan-based drug “Avecardit®” in tooth extraction in dogs with chronic valvular regurgitation. valve regurgitation. The study involved 40 clinically healthy dogs (from the point of view of other organs) with verified grade B2 mitral valve endocardiosis. Group I (n = 20) received “Avecarditis®” at a dose of 0.25 mg/kg twice daily 7 days before surgery and for 7 days after, group II (n = 20) served as a control without preoperative drug support.

Regional blockade with bupivacaine was used for anesthesia. Monitoring included electrocardiography, pulse oximetry, noninvasive blood pressure measurement, and recording of readings every 5 minutes.

The results of the study showed that the preoperative use of pimobendan-based drugs significantly reduces hemodynamic complications and ensures a more stable course of anesthesia. The dogs of group I demonstrated better hemodynamic stability with a lower degree of reduction in blood pressure (14.2% in group I versus 31.8% in group II). No complications related to the cardiotoxicity of local anesthetics have been reported.

The developed anesthetic protocol can be recommended for use in dental operations in dogs with mitral valve endocardiosis. 

This article presents scientific data on the effect of a betulin-containing feed additive on immunoglobulin levels in calves and dairy cows under livestock farming conditions. The study examined data obtained from a study conducted on five- and ten-month-old calves and dairy cows, divided into experimental and control groups. At the beginning of the experiment, serum analysis revealed that immunoglobulin levels were below normal in some animals in both the control and experimental groups. During the study, a betulin-containing feed additive was added to the daily diet of animals in the experimental groups. The additive was administered orally at a dose of 10 mg/kg of body weight once daily for 14 days.

Repeat serum analyses of animals in the experimental and control groups revealed that, in animals in the experimental groups with initially low immunoglobulin levels, these values shifted from low to optimal by the end of the experiment, demonstrating positive dynamics across the group. However, similar indicators in animals in the control group remained unchanged.

It was established that the use of a supplement containing betulin affected the immune status of the experimental animals, indicating its immunostimulatory effect. 

Relevance. Heat stress significantly influences the physiological state of dairy cattle, affecting their milk yield and milk quality. Various techniques exist for assessing heat stress in dairy cattle based on meteorological parameter values.

Methods. A retrospective analysis was performed on climate data arrays collected at weather stations in regions belonging to the Volga Federal District over the period from 1970 to 2024. The values of the temperature and humidity index (THI) and the equivalent temperature index (ETI) were calculated, the comfort of environmental conditions was assessed, and the severity of thermal stress was determined.

Results. In the Volga Federal District, on average, 16.24% of THI values indicated thermal stress in dairy cattle, with the majority (12.38%) categorized as moderate heat stress by severity. The maximum proportions of TVI values characteristic of heat stress were found in the Orenburg and Saratov regions (27.49% and 27.44%), the minimum — in the Perm Region (9.87%). Variability in regional ranking was noted depending on the chosen THI calculation methodology. The most frequent occurrence of THI corresponding to moderate-level heat stress was registered in Orenburg region (19.96%), with the least occurring in Perm Krai (7.85%). The average ETI index representing heat stress among Volga Federal District entities was 14.82%, reaching up to 19.69% in Penza region and down to 10.94% in Perm Krai.

The article presents data on the live weight and meat productivity of first-generation (F1) crossbred lambs obtained from crossing Jaidari breed ewes with Hissar breed lambs, which is a scientific basis for increasing the meat productivity of tailed sheep breeds in the natural and climatic conditions of the Republic of Karakalpakstan. It was found that at the age of 18 months, lambs of the second group (Hissar pure breed) and the third group (Hissar x Jaidari) of the first generation (F1) outperformed their peers from the first group (Jaidari pure breed) in live weight, respectively, by 6.0 kg, or 9.2% (p < 0.001), and by 4.4 kg, or by 6.7% (p < 0.01). This indicates the high genetic potential of these animals in the formation of live weight and meat productivity, as well as their good adaptability to the environment and the high potential of breeding sheep, as well as the main absolute and relative indicators of slaughter results. Group II (pure Hissar breed) and Group III (½ Hissar x ½ Jaidari) bred first-generation sheep (F1) compared to their peers in Group I (Jaidari breed), respectively, by 15.6 kg, or by 33.5% (p < 0.001), and 5.6 kg, or by 12.0% (p < 0.01), uncooled carcass weight — by 9.4 kg, or by 47.7% (p < 0.001), and 5.2 kg, or by 26.4% (p < 0.01), slaughter weight — by 13.5 kg, or 59.5% (p < 0.001), and by 6.8 kg, or 29.9% (p < 0.01), slaughter yield of sheep — by 48.8%, 58.3% and 56.7%, respectively, which is 9.5% and 7.9% higher than that of their peers Group I (Jaidari). Thus, based on the scientific basis for increasing the meat productivity of tailed sheep breeds in the natural and climatic conditions of the Republic of Karakalpakstan, the first-generation (F1) crossbred lambs obtained as a result of crossing purebred Hissar and Jaidari sheep with Hissar sheep showed high live weight and meat productivity indicators, which testifies to the high genetic potential of feeding them with complete and rationed feeds in pasture conditions. 

Relevance. The increasing need for herd maintenance leads to a decrease in the age of first insemination. At the same time, the influence of the age of the first insemination on the productive qualities of cows and the duration of their productive use is not analyzed. The aim of the work is to analyze the correlation of the age of the first insemination of heifers on their further productivity, depending on the age of cows.

Methods. The study involved replacement heifers and cows born in 2018, which were categorized into six groups based on their AFI: ≤ 12 months (including subgroups with early insemination at 9, 11, and 12 months), and 13, 14, 15, 16, and 17–18 months. Data for the analysis were sourced from the IAC “SELEX-Dairy Cattle” database and complemented by our own research. We examined the distribution of heifers by AFI, milk yield dynamics over four lactations, and calculated both the average milk yield per lactation and lifetime milk yield. Dairy productivity was assessed through controlled milk recordings.

Results. It was found that the largest number of repair heifers were inseminated at 14 months (with slight fluctuations from 13 to 15 months). The highest duration of the productive period was found in the group of cows with the age of the first insemination of 14 months (3.72 lactation), and the shortest — 17–18 months (3.0 lactation). The highest productivity rates on average over the period of productive use of cows were found in animals that were inseminated at the age of 16 months — 10,844 ± 138.79 kg.

The study revealed that the age at first insemination influences the pattern of lactation performance as cows age. Cows inseminated at 13–15 months of age were the most efficient in terms of milk yield per lactation, which contributed to their higher lifetime productivity. 

Modern methods of breed formation in animal husbandry underscore the importance of studying the influence of genetic factors on the productive qualities of farm animals. This research analyzes the association between candidate gene polymorphisms and meat productivity indicators and immune status in sheep. Genotyping of the GH, GDF9, and CAST loci was performed using the PCR-RFLP method in a sample of Dagestan Mountain sheep. Statistically significant associations were established between the genetic variants and the traits under study. Animals with the GH/HaeIII AB and GDF9/AsplEI AA genotypes were characterized by an increased level of CD4+ lymphocytes and a reduced content of CD8+ cells, resulting in higher values of the immunoregulatory index compared to carriers of the GH/HaeIII AA and GDF9/AsplEI GG genotypes. Analysis of productive qualities revealed the advantage of the CAST MM genotype over CAST MN in terms of live weight. A similar pattern was established for the GH AA genotype compared to GH AB. The obtained data demonstrate the promise of using molecular genetic markers in breeding programs for the simultaneous improvement of both productive characteristics and the immune status of sheep. 

Relevance. Insulin-like growth factor-1 (IGF-1) is involved in the regulation of meiosis in vivo and is therefore actively investigated as a potential regulator of oocyte quality aimed at improving the efficiency of in vitro embryo production biotechnologies. In the present study, we examined the effect of IGF-1 during bovine oocyte culture in terms of their in vitro maturation, embryonic development after artificial activation, and the quality of the resulting embryos.

Materials and methods. Oocytes isolated from ovarian follicles were cultured either in the absence (control) or presence of various concentrations of IGF-1 (5, 10, 20, 40, and 80 ng/ml). Matured oocytes were then artificially activated and cultured for 7 days to support embryonic development.

Results. IGF-1 had no effect on oocyte maturation, cleavage, or the number of nuclei in blastocyst. At the same time, a concentration-dependent effect of IGF-1 on the development of oocytes to the blastocyst stage was observed. In the control group, the blastocyst yield was 17.3±1.6%. The presence of IGF-1 in the maturation medium at concentrations of 5, 10, and 20 ng/ml increased this rate to 29.9±4.5, 30.7±3.6, and 29.6±2.3%, respectively (p < 0.05). Thus, at these concentrations IGF-1 can be recommended for in vitro maturation of bovine oocytes. 

Modern industrial pig farming is based on highly productive breeds, however the globalization of breeding has reduced genetic diversity, increasing the vulnerability of the industry. In this context, native breeds such as the Hungarian Mangalitsa are valuable due to their unique adaptive and productive qualities. Previous genetic studies of this breed were limited to microsatellite and mitochondrial markers. However, in the context of the development of modern genomic technologies, the use of SNP analysis is of particular relevance. This study is the first to use SNP analysis to assess the genetic diversity of the Russian Mangalitsa population in comparison with the Hungarian population and commercial breeds (Duroc, Large White, Landrace), as well as wild boar. The obtained results showed that the Russian population of Mangalitsa retains high genetic variability (HO = 0,337 ± 0,001, AR = 1,952 ± 0,001), exceeding the indicators of the original Hungarian group (HO = 0,218 ± 0,001). PCA analysis confirmed the closeness of Russian and Hungarian Mangalitsa, as well as the absence of hybridization with commercial breeds. Cluster analysis revealed a genetic component of wild boar, which corresponds to the history of the breed formation. The Russian population of Mangalitsa is genetically similar to the Hungarian one and can serve as a valuable resource for selection, especially in conditions of adaptation to low temperatures. The data obtained are important for the conservation of biodiversity and the development of specialized pig breeding. 

In modern realities, specialized breeds of livestock demonstrate the highest economic efficiency. However, there is a significant risk of losing the unique gene pool of domestic breeds. The Kostroma breed of cattle is an outstanding achievement of breeders and possesses a number of valuable qualities. One of the remarkable founders of the breed was the bull Salat 1216, the breed champion in 1954. The breeding line of Salat 1216 still has great genetic potential.

The objectives of the work are a comparative study of museum and modern samples of Kostroma cattle, an analysis of the preservation and prevalence of the genetic components of the Lettuce 1216 bull in the modern population of the breed.

The material consisted of fragments of the tooth of bull Salat 1216. Historical samples of the Kostroma (KSTRM_H, n = 3) and Brown Swiss (BRSW_H, n = 5) breeds, dated to the first half of the 20th century, were used as comparison groups, along with modern samples of the Kostroma breed (KSTRM, n = 60) and samples of the Brown Swiss breed from two populations: those bred in Russia (BRSW, n = 23) and those bred in Germany (BRSW_G, n = 57). Nine microsatellite markers were genotyped. Data analysis was conducted using the GenAlEx program and the R programming environment. The allele profile of Salat 1216 matched the profile of KSTRM_H at 6 out of 9 loci, and at 4 out of 9 loci with the profile of KSTRM. In the modern Kostroma breed, genetic components characteristic of bull Salat 1216 predominated (on average, 64.82%). The studies showed the distinctiveness of the genetic profile of the founder of the Kostroma breed, bull Salat 1216, from the improving Brown Swiss breed and confirmed the preservation of the genetic components in modern populations of the Kostroma breed. 

Relevance. Research in the field of population genetics is one of the main tools for forming a breeding strategy and increasing the economic efficiency of reindeer husbandry.

Methods. The object of the study was the reindeer of the Komi Republic (PSK, n = 100) and the Yamalo-Nenets Autonomous Okrug (Yamalo-Nenets Autonomous Okrug) (YOS, n = 100). Plucks from the auricle and antlers were used for genetic analysis. The genotype of the animals was determined by 16 microsatellite markers using the COrDIS Reindeer multiplex PCR test system. The statistical analysis was performed in the GenAlEx 6.503 program.

Results. The Shannon index indicated high allelic diversity in Rt1 (PSK) and OheQ (PSK, YOS) loci, with minimal diversity in BMS745 and C276. The PSK population was characterized by high observed heterozygosity in Rt9 (0.940) and low in C143 (0.430), while among YamaloNenets Autonomous District animals, the maximum values were in Rt1 and OheQ (0.880), and the minimum values were in C143 and C276 (0.350). Assessment of the fixation index in PSK deer revealed an excess of heterozygosity in Rt9 and Rt6, a deficiency in BMS1788, and in YOS animals there was an excess in T40 and a deficiency in C276. The PSK population had a higher margin of heterozygosity (0.040, р < 0.05) relative to YOS. A comprehensive analysis revealed 7 unique sequences in PSK deer and 4 in YOS. The frequencies of private alleles were 6% and 4%, respectively. The Wright fixation index showed moderate divergence between populations at loci BMS1788, Rt1, C143, C276, and C32, and significant divergence at BMS745. The Gst and Dest scores confirmed these results. Overall, the YOS population turned out to be less genetically diverse compared to the PSK. To reduce the level of inbreeding in the YOS herd, it is necessary to organize the import of producers from other populations. 

Relevance. The current state of the economy largely determines the development ofagriculture, including crop production, the effectiveness of which largely depends on thecorrect selection and ratio of crops and varieties. The revival of linen production and the textileindustry in the Smolensk region is not just a local task, but a strategically important step forthe whole of Russia.However, despite the positive developments, there are also problematic issues. The imperfection of technologies used in the cultivation, harvesting and primary processing of flaxhas led to a decrease in the quality of flax fiber. Previously, agricultural producers receivednumber 14 flaxen fiber, but now the value of this indicator has decreased to 9–10. The mainfactors contributing to increasing the efficiency of flax production are the introduction of newvarieties of flax, the establishment of a seed production system, the development of moderntechnological methods of cultivation, the study of the responsiveness of new and promisingvarieties to sowing dates, seeding rates, fertilizers, etc.Methods. The objects of the research were 10 types of mineral fertilizers recommended by“PhosAgro” on the flax-flax Phoenix variety.Results. The use of complex mineral fertilizers in the cultivation of flax of the Phoenix varietyon sod-podzolic soil with agrochemical parameters typical of the Smolensk region made itpossible to increase the yield of flax from 4.93 to 6.96–9.49 t/ha, flax seeds — from 0.20 to0.23–0.34 t/ha. The greatest biological efficiency among the proposed fertilizer applicationsystems was shown by options with pre-sowing application of N₃₂P₁₀₉K₁₁₂ (TCU with sulfurand boron + “Ammophos” + “Kalimag”) in combination with fertilizing N₂₀ (ammonium nitrate + Zn-Mo micro fertilizers) and pre-sowing application of N₄₅P₁₀₅K₁₀₅ (TCU with boron + PK fertilizer with sulfur and calcium) in combination with top dressing N₁₅ (ammoniumnitrate). The other options for applying fertilizers in terms of yields of flax and flax seeds weresignificantly inferior to the best of the proposed ones.

Relevance. In the conditions of climate aridization, paisa is a promising fodder crop. This choice is due to its relative drought resistance, ability to adapt to extremely high temperatures, and at the same time to maintain the yield and quality of biomass and grain. These characteristics allow paisa to be cultivated in various regions of the country, which makes it promising for the agro-industrial complex.

The purpose of the study — to evaluate economically valuable features of a new variety of paiza Lada adapted for cultivation in arid regions of the Russian Federation.

Methods. The research was conducted in the southern part of the Chernozem zone of the Volga region at the experimental field of the Russian Research Institute of Sorghum from 2020 to 2023, according to generally accepted methodological guidelines.

Results. Thе article presents the results of the creation of a new variety of Lada paiza, which has passed state testing and is approved for use in the Lower Volga region of the Russian Federation starting from 2024. During the competitive variety testing, the average yield of green mass was 32.1 t/ha, which is 4.60 t/ha higher than the standard variety Gothic. The variety is characterized by high productivity and resistance to abiotic stressors at different stages of ontogenesis: leaf tissue hydration (72.3%) during flowering and root length index (0.88) at the initial stages of ontogenesis. It is characterized by rapid regrowth after mowing and allows for up to three mowing in the conditions of the rainfed area, and is resistant to lodging. No diseases or pest damage was observed in the Lada variety during the years of research. 

Blast (causative agent — ascomycete fungus Pyricularia oryzae Cav.) is the most dangerousand harmful disease of rice, widespread in most rice-growing regions of the world, includingRussia. For 10 years (2013–2022), the condition of rice crops was monitored in ricegrowing farms of the Krasnodar Territory. At the infection site, under artificial infection, theimmunological properties of 13,158 variety samples transferred by breeders of the FederalRice Research Center and the Collection of Genetic Resources of Rice, Vegetable and MelonCrops were studied. The resistance was assessed on a ten-point scale of the InternationalRice Institute (IRRI) using visual and immunological diagnostics, as well as phytopathologicalobservation. The ranges and optimal values of environmental factors contributing to variousstages of the Pyricularia oryzae life cycle were established. It has been shown that for theeffective germination of conidia, the formation of apressoria and the penetration of thepathogen into plant tissues, the temperature in the range of 25–28 °C, relative humidity (above89%) and prolonged moistening of the leaf surface (at least 6 hours) are of key importance.The analysis showed that among the studied variety samples, 11.3% are resistant to blast,38.4% are moderately resistant, and 50.3% are susceptible. The paper presents a quantitativepredictive model reflecting the transformation of the varietal composition of rice classified bythe level of resistance to the fungus Piricularia oryzae, which serves as a scientific basis for thedevelopment of an adaptive breeding strategy. Of particular importance in this strategy is theselection of resistant varieties that provide built-in protection, reducing the need for chemicalfungicides and contributing to a stable yield. A promising direction is the creation of genotypescarrying R-genes of a wide range of resistance.

In the context of global climate change, characterized by rising temperatures and reduced rainfall, the selection of adaptive crop varieties has become a priority.

The purpose of the study is a comprehensive assessment of the adaptability and stability of 13 soybean lines in the contrasting soil and climatic conditions of the forest-steppe of the Middle Volga region (Samara region) in 2021–2023.

The research methodology included the calculation of regression coefficients (bi), stability (σ2d), adaptivity (KA), homeostaticity (Hom) and other parameters. It was found that the highest yields (1.76–1.85 t/ha) and complex adaptability were shown by the lines L 312, L 5162/17 and L 5007-2/17, exceeding the standard Yuzhanka variety by 1.7–13.5%. A strong positive correlation of yield with compensatory capacity (r = 0.73), environmental plasticity index (r = 0.99) and adaptability coefficient (r = 0.95) was revealed. The L 319 line, which has shown high breeding value and stability, has been transferred to the state variety testing. The results of the work allow us to identify promising genotypes for the creation of highly productive and resistant soybean varieties. 

The problem of genetic purity of agricultural crop varieties is one of the key issues in the field of agricultural biology and its importance in the agricultural sector of the economy is constantly increasing. The uniformity of the genotypic and phenotypic characteristics of plants within the variety makes it possible to preserve its unique properties from generation to generation. However, due to the influence of many factors from natural mutagenesis, gene drift, over-pollination and violations of seed production technologies, the purity of the variety can decrease significantly. The introduction of molecular genetic labeling technologies into seed breeding practice will contribute to an effective and rapid assessment of the genetic purity of varieties.

The purpose of this work is to evaluate the genetic uniformity of flax lines using various SSR marker complexes.

The objects of the study were 4 flax lines, each represented by 16 samples. Genomic DNA was isolated from plant leaves using a modified CTAB-method. SSR-marker complexes of domestic and foreign development were used in the work. After PCR was performed with each line of SSR-markers, a fragmentary analysis was performed, based on which the genetic uniformity of the studied flax lines was evaluated and compared. Data analysis showed that all the lines studied were heterogeneous in composition to varying degrees, with the M-326 line being the most variable and the P-268 line being the least variable. Both marker complexes used showed high information content and complementarity of the data obtained. Based on the results of the research, the most promising SSR-markers have been identified, the further use of which will ensure the best results and accuracy in data interpretation. 

The article presents the results of research on the optimization of agricultural techniques for cultivating the Ata-baba hazelnut variety in the conditions of the southeastern foothill subprovince of Dagestan. It was established that the optimal load for a bush is 8–10 skeletal shoots, which ensures a yield of 2.3 kg per bush (1.15 t/ha). The advantage of a standard (tree-like) formation over the traditional bush form was demonstrated: yield with the standard form reached 1.6 t/ha compared to 0.9 t/ha with the bush form, representing an almost two-fold increase. An assessment of the agroclimatic resources of the subprovince was conducted, confirming the feasibility of sustainable cultivation of the crop, although a risk of damage to male inflorescences by late spring frosts was noted. Based on the analysis, criteria for evaluating the technological suitability and adaptability of hazelnut varieties were developed. A promising research program for studying introduced varieties has been defined. The results of the work are of practical importance for the development of commercial nut farming in the region. 

This article presents the results of an experimental study on the anaerobic digestion of Chlorella kessleri microalgae biomass, preliminarily cultivated under elevated CO₂ concentrations. The digestion process was carried out with the addition of food waste and cow manure as an inoculum.

The aim of the work is to determine the optimal ratio of the components of the fermentation mixture (microalgae — food waste — inoculant) for organic carbon for maximum biogas yield and its energy potential (in terms of methane content in biogas).

It was found that the best results (1,018 liters of biogas and 67.3% methane) were achieved with a ratio of 1.0 g — 3.2 g — 4.0 g, while the maximum proportion of methane (67.8%) was recorded with the addition of 1.2 g of microalgae.

The obtained results support the recommendation to use Chlorella kessleri biomass, previously cultivated under elevated CO₂ conditions, as an additive in co-anaerobic digestion with food waste and inoculum. This approach is proposed as an energy-efficient, environmentally friendly, and economically viable method to enhance the biogas potential of feedstock mixtures. 

The article presents the results of a study of the effect of dry and wet cleaning of the skin of cows using automatic brushing devices on the level of thermal stress in summer in a dairy farm. The experiment was conducted on 30 cows in June 2024 at the State Farm named after him. Lenin Street, Moscow region. The animals were divided into three groups of 10 cows each. The study was conducted at an air temperature in the cowshed from 22 to 26 °C, increasing during the day, and a relative humidity of 55%. One of the groups is a control group, the second has access to a classic automatic brush (dry cleaning), the third group has access to an automatic brush with a brush pile wetting device (wet cleaning). The results showed that the use of dry and wet cleaning of the skin makes it possible to reduce the temperature of the skin at 26 °C by 1.5 °C and 4.6 °C, respectively, in comparison with the group of animals where animals did not have access to an automatic brush. As the ambient temperature increased from 22 to 26 °C at a relative humidity of 55%, the frequency of use of automatic brushes by animals increased. At the same time, as the ambient temperature increased, the frequency of animal approaches to automatic wet cleaning brushes increased by 13%. As the ambient temperature increases, the use time of automatic brushes by cows also increases. At a temperature of 26 °C, the average use time is 24% higher for wet cleaning brushes. The effect of using automatic moisturizing brushes to reduce thermal stress in cows has been established, providing the opportunity, in addition to local forced ventilation systems, to individually cool each animal according to its thermal sensations.