RUDN Journal of Agronomy and Animal Industries

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Feeding balanced in amino acids, micro and macro elements, vitamins and other biologically active substances is a necessary condition for the productivity and development of fur animals, as well as for obtaining high-quality fur raw materials. Analysis of the amino acid profile of the main productive diet of the mink at JSC Fur Farm “Saltykovsky” revealed a deficiency of the essential amino acids: histidine, tryptophan and threonine, when maintaining a total protein within the normal range. To correct protein metabolism, a hydrolysate from sable and mink carcasses after technological euthanasia and skinning was included in the diet of minks. The hydrolysate is sterile, does not have pyrogenicity, acute and chronic toxicity, does not cause allergic reactions, contains 18 amino acids, including 10 essential, 6 macronutrients (Ca, Na, S, Mg, K, P) and 18 trace elements. A scientific and economic experiment was carried out by a commission on the basis of JSC Fur Farm “Saltykovsky” on standard wild mink 3 months of age, of which 1 control and 2 experimental groups of 120 animals each (60 males and 60 females) were formed. The results of the experiment showed that the feed additive in doses of 2 and 4 ml of a 15% solution per capita mixed with feed of the productive diet once a day for 4 months has a tonic effect on the mink organism.

The results of prooxidant-­antioxidant control of the efficiency of various schemes of aerosol complex therapy for acute catarrhal bronchopneumonia in calves using the generally accepted scheme (aerosol treatment indoors with iodotriethyleneglycol solution with intramuscular administration of the drug ”Penstrep‑400“), as well as schemes proposed by us, based on previously conducted studies to determine the sensitivity of isolated microflora to antibacterial drugs (aerosol treatment indoors with iodotriethyleneglycol solution with intramuscular administration of the drug ”Marfloxacin“) and phytobiotics (aerosol treatment indoors with Hypericum perforatum wort extract with intramuscular administration of the drug ”Marfloxacin“) were presented. Black-and-white calves, aged 1–3 months, mixed sex, with clinical signs of acute catarrhal bronchopneumonia were studied. The sick animals were divided into three experimental groups using the envelope method: ₁O — experimental 1, n = 20; ₂O — experimental group 2, n = 20 and ₃O — experimental group 3, n = 20 and placed in separate isolators. During the treatment of animals in group ₁O, the general clinical improvement occurred only on the 9.25 ± 0.91 day, while six cases of complications occurred, and two animals died. The treatment of calves in group ₂O was accompanied by the general clinical improvement 2.05 days earlier, compared with group ₁O, and all animals recovered. Therapy in group ₃O contributed to the general clinical improvement already on the 4.90 ± 0.64 day, which is 47.0% earlier compared with the indicators of group ₁O, and all 20 calves also recovered. The study of the processes of lipid peroxidation and antioxidant protection in blood plasma of experimental calves in the dynamics of treatment confirmed the best result in ₃O group, which was accompanied by a significant decrease in LPO products and an increase in AOS indicators, which already on the 7th day of observation approached the physiological norm.

The effect of the variability of certain climatic parameters during the growing season on the cultivation of sunflower (Helianthus annuus L.) in the Orenburg region was studied. It was shown that the growth and development of Helianthus annuus L. are significantly influenced by both humidity and temperature, but the amount of these parameters changes over time due to the ongoing climate change. In this regard, one of the principles of agronomy is to identify relationships between the phases of phenological development in the context of changing weather conditions. It allows to assess the measures aimed at adapting sunflower to a specific cultivation zone. Timely implementation of these measures will enable us to manage the susceptibility of the agricultural sector and predict crop yields. The present study is based on registration of eight phenological phases from sowing to harvesting for three years and assessment of the influence of weather factors of a particular season on both ontogenesis of the crop in general and duration of each phenological phase in particular. According to the results of observations, it was found that the duration of Helianthus annuus L. cv. ‘Poseidon 625’ vegetation in climatic conditions of Orenburg region was on average 99 days and is determined by the timing from the formation of the first and second pairs of true leaves to seed formation. The phenological periods requiring maximum moisture were determined — from sowing to germination and from flowering to seed filling (r = 0.9, the significance level is 90%). The data obtained during the study can be used by farmers and agronomists to determine the optimal timing of sowing oilseeds not only in Orenburg region, but also in each specific region engaged in their production.

Tomato protection from diseases is necessary to obtain high yields of quality fruits. In protected soil conditions, tomatoes bear fruit for up to 265 days, while the fruits are harvested 1 or 2 times a week starting from 60 days after seed germination for early varieties and 100 days for late varieties. When growing tomatoes, especially during the fruiting period, it is optimal to use biological pest control agents, which, unlike chemical ones, are harmless to humans and do not accumulate in the fruits. Existing biological products are not effective enough against the entire range of tomato diseases. It is necessary to look for new strains of microorganisms. This paper presents the results of the study of strain 23B78/1 Serratia plymuthica with the aim of exploring the prospects for its use as a biocontrol agent. Pesticides based on this species are not registered in the Russian Federation. Species identification was determined by 16S gene sequence analysis and biochemical profiling. Antagonistic activity against phytopathogenic fungi was assessed in vitro using double culture method. Phytotoxicity testing was carried out on germinating seeds of tomato. Evaluation of antagonistic effect revealed effectiveness against the following phytopathogenic fungi: Alternaria solani, Botrytis cinerea, Colletotrichum truncatum, Fusarium citri, F. incarnatum, F. duofalcatisporum, F. incarnatum, F. oxysporum, Globisporangium ultimum, Sclerotinia sclerotiorum. The maximum antagonistic effect was observed during paired fusion with fungus B. cinerea, mycelium of which grew strictly in the opposite direction from the bacterium. Germination of tomato seeds in presence of strain 23B78/1 did not reveal any inhibitory effect on seed germination and development of young tomato plants. The conducted research shows that the strain Serratia plymuthica 23B78/1 is promising for creation of biofungicide for protecting tomato plants.

In this study, it is optimized by the methods of preparing samples for the release of genetic material (DNA) from soybean cyst-forming nematode Heterodera glycines , which is necessary for accurate identification. Various modifications of ready-made reagent kits from Russian and foreign manufacturers were tested: DNA-Extrane-2, FitoSorb, TsytoSorb, ORB-GMO-A by Sintol LLC (Russia), Proba-GS, Proba-NK by AgroDiagnostika LLC, and QIAamp DNA Mini Kit by Qiagen (Germany). By testing the PCR method «In real time», the sensitivity of Heterodera glycines total DNA release was tested using a test system consisting of forward and reverse primers and a modified probe: SCNrtF (5’-AAATTCCAGGCCGCTATCTC-3’), SCNrtR (5’CGTGGACTGAACTGAACTGGACAAAG-3’), SCNrtP (5’-FAM/-TGGGCTGGGTGCTTCTAGAACTTTT-/ BHQ-1/-3’).

Immunogenetic analysis is of practical interest, allowing us to establish not only the relationship between animals, but also the degree of genetic influence of individual stud bulls on the entire gene pool of the population. While preserving the gene pool, the study of the frequency distribution of blood groups, as well as their changes over time, allow us to judge the processes occurring in closed populations. The research was carried out in the gene pool farm of the Red Gorbatov breed. The brood stock has 8 systems of blood groups. In 2007, 45 antigens were detected in the herd, in 2009 there was a decline in diversity to 38 antigens, but in 2010 their number was restored to 46, by 2017 the total number of antigens had not changed significantly — 47, and in 2022 again 46. The most numerous is EAB system, from 21 to 28 antigens were established in this system in different years. The structure of antigens is unstable, some antigens that were widespread in 2007 (Y₂ and C₂) decreased to 14…32 % in 2017. New antigens were established — O₃, O₄, O_x, and A’₁. The loss of individual antigens may indirectly indicate the loss of other alleles that have economic importance; therefore, animals with rare antigens should be used in reproduction to a greater extent. The stud bulls whose seed stock is available at that moment have different antigenic composition: from 3 to 17 antigens in different systems. The use of a limited number of bulls can lead to the drift of individual genes.

Information about the current situation with actinobacillus pleuropneumonia (APP) in the Russian Federation is quite limited, which makes it difficult to assess the effectiveness of current preventive measures and develop new strategies. The diversity and effectiveness of vaccines play an important role. The main aim of the study is a scientific review of modern approaches to the APP prevention in pigs and prospects for the development of a vaccine that provides comprehensive protection against all known serotypes of this pathogen. The methods of systematization, critical analysis, and problem review are used. Over the years, various vaccines have been developed to combat this disease. Inactivated bacterial vaccines provide a strong immune response, but their effectiveness may vary. Based on the outer membrane proteins and three Apx toxoids, subunit vaccines are able to provide protection regardless of the APP serotype. DNA vaccines show promising results but require further research. Live attenuated vaccines contain weakened microorganisms and stimulate strong immunity, but their use also has its own difficulties. Despite all the successes achieved, at the moment there is no reliable and commercially profitable vaccine that would protect against all known serotypes of A . pleuropneumoniae and prevent the carriage and transmission of the disease. The problem of specific prevention of APP requires an integrated approach, including further scientific research, the development of new technologies and innovative methods of vaccination. Scientists increasingly focus on research in the field of oral and nasal vaccines. One of the important advantages is cost-effectiveness and safety during production, as well as convenience and safety of vaccine application. Oral and nasal vaccines can significantly simplify the immunization process, especially in the context of mass vaccination. Studies of vaccines based on external membrane vesicles and transgenic plants show promising results.

The aim of this study is to investigate the immunological parameters of blood in lactating cows with serous-catarrhal mastitis to identify the pathogenetic mechanisms of the disease. The research was carried out in autumn in one of the livestock farms of the Amur region. The object of the study was lactating cows of Holstein breed at 2-4 months of lactation. Groups of cows were formed by 10 animals in each: control (healthy) and experimental (sick with serous catarrhal mastitis). The inflammatory process in the mammary gland of lactating cows was caused by tissue damage and complicated by opportunistic microflora. Protein metabolism disorders (hypoalbuminemia, dysproteinemia) and signs of haemoconcentration (increased haematocrit and haemoglobin, erythrocytosis) were observed in sick animals. Conditionally pathogenic microflora and products of inflammation in the mammary gland stimulated cellular and humoral immunity.