Rising prices of traditional feedstock for feed preparation (fish meal and oil) is a problem for aquaculture enterprises. Their replacement with inexpensive components of vegetable origin is the way for solving the problem. The aim of the study is to generalize and analyze scientific data on using new types of vegetable feedstock in aquaculture feeds, on technologies of their preparation and use, influence on feed quality. Selection and systematic review of scientific literature on the topic of the study for the period of 2017-2022 has been carried out. The derivatives of land agricultural plant products such as oilseed meal, protein concentrates, gluten and food industry wastes are the main types of vegetable feedstock for feed preparation in aquaculture. Currently, vegetable oils are the best variants for replacing fish oil in fish diets. Partial or complete replacement of fishmeal and oil with new types of vegetable feedstock is possible and does not lead to deterioration of fish health and growth rate when these components are included in the diet at recommended doses. Such a replacement is economically advantageous. But there are negative effects in the use of vegetable feedstock, such as the presence of anti-nutritional factors that limit its use in aquaculture. The development of recipes of cost-effective fish feeds in which fish meal and oil are completely replaced by vegetable components is a research priority for the development of intensive aquaculture.

Avian influenza viruses are epidemiologically dangerous zoonotic pathogens that can cause high morbidity and mortality both in animals and in humans. Reassortment and antigenic shift in the genome of the avian influenza virus draw to a change in its properties: host range, virulence, and other factors. The natural reservoir of avian influenza is wild waterfowl, which can transmit the virus to poultry through the direct contact. The exchange of antigenic sites of viruses occurs over several months in the traditional wintering grounds of migratory birds. Avian influenza viruses with altered genes as a result of reassortment, circulating in wild migratory birds, carry epizootic threat of spread of the disease to the unharmed areas. In this review of highly pathogenic avian influenza there has been analyzed the epizootic situation and possible vaccination strategies that exist in the world. The spatial trend in the spread of highly pathogenic avian influenza in the constituent entities of the Russian Federation was determined using the GIS tool, Median Center in the working environment of the ArcGIS Pro software. Based on the review of selected literature, it has been established that vaccination itself is not considered a solution to the problem. Without monitoring systems, stringent biosecurity and population reduction in case of outbreaks, the control and eradication of the disease is impossible. The decision to vaccinate against avian influenza should be made on a case-by-case basis, weighing all the risks of further spread and mutation of the virus. All industrial poultry enterprises exporting the products must operate in a closed mode and be excepted from the list of vaccination.

The article presents data of 2019-2021 on the influence of agroclimatic conditions and doses of mineral fertilizers on the grain productivity of 13 varieties of spring triticale. A close dependence of the yield of triticale varieties on the reserves of productive moisture in the soil layer of 0-50 cm was established for the periods May-June (r = 0.73) and July-August (r = 0.85). Without the use of mineral fertilizers in arid conditions with reserves of productive moisture in 0-50 cm soil layer from 61 to 92 mm in the first half of the growing season, the grain productivity of spring triticale varieties was less than 3 t/ha. Under more favorable conditions of soil moistening (154 mm), the yield was almost 4 t/ha, which is a very good indicator for the conditions of Mari El Republic. Against the background of the application of mineral fertilizers in doses of N30-60P60K60, the grain productivity of varieties increased: Rovnya by 20-33 %, Saur ‒ 57-78 %, Savva ‒ 5-22 %, Timur ‒ 39-77 %, Dobroye ‒ 42-60 %, Zaozerye ‒ 38-40 %, KNIISKH 9 ‒ 16-40 %, KNIISKH 11 ‒ 12-30 %, KNIISKH 22 ‒ 22-28 %. On average, over three years of research, the varieties of spring triticale Dobroye (3.43 t/ha), Savva (3.12 t/ha) and KNIISKH 9 (3.26 t/ha) were characterized by a weak reaction to unfavorable soil moisture conditions and provided consistently high productivity of feed grain. The case of Dobroye variety, the most optimal variant for cultivating spring triticale in a simulated agrophytocenosis with a seeding rate of 4 million germinating seeds per hectare when applying N60P30K30 is established. On average for two years of the research the yield of this variety has reached 4.12 t/ha with a seeding rate of 4 million germinating seeds per hectare, which is 8 % higher than the control (3 million germinating seeds per hectare) and 22 % higher than in the variant with a seeding rate of 5 million pcs/ha.

The research was aimed at comparing the characteristics of winter wheat precursors on leached heavy loam chernozem in the conditions of the Republic of Mordovia. The object of the study was winter wheat of the Mironovskaya 808 variety, grown in grain-grass-fallow-row (1996-1997) and grain-grass-row (2008-2009) crop rotations, where the precursors were pure fallow and lucerne grass of the 3d year of use. In the control variant (without lime and mineral fertilizers), the crop yield after pure fallow was 3.27 t/ha, after perennial grasses it was 3.72 t/ha. Liming of the soil introduced in 1989-1990 and 1999-2000 did not make significant changes in crop yield, but the combined action with fertilizers in the grain-grass-fallow-row crop rotation against the background of liming by 1.0 h. a. contributed to a greater increase (0.43 t/ha) than against the background of liming by 0.5 h. a. (0.28 t/ha). In grain-grass-row crop rotation, on the contrary, against the background of liming by 0.5 h. a, more grain was obtained (0.74 t/ha), than against the background of 1.0 h. a (0.51 t/ha). The effect of fertilizers without lime was estimated by a less increase in yield ‒ 0.36 and 0.78 t/ha, respectively by crop rotations. Taking into account the payback of 1 kg a.i. of mineral fertilizers with an additional grain yield and additional income, the following doses can be recommended in addition to phosphorus-potassium: the use of nitrogen fertilizer in the top-dressing in the following doses: in the grain-fallow-grass-row crop rotation not more than 30 kg a. i., in grain-grass-row ‒ 30-60 kg a.i. against the background of soil liming by 0.5 h. a.

The purpose of the research is to identify the main elements of the crop structure that affect the productivity of spring barley in different weather conditions in the Ryazan region. Field studies were carried out in the nursery of the competitive variety trial in 2017-2021 on dark gray forest heavy loam soil. The best zoned double-row varieties of spring barley (Yaromir, Nadezhny, Znatny, Raphael, Lyuboyar) and 4 promising lines were used as the object of research. It has been established that there is a relationship between the elements of the structure of the spring barley yield: the formation of one of the elements can be compensated by a more significant development of the other. In conditions of severe drought (НТС = 0.58-0.70), the greatest positive correlation of yield with the length of the ear (r = +0.437) and the number of grains in the ear (r = +0.279) was revealed. In arid conditions (НТС = 0.75-0.85), the number of plants before harvesting (r = +0.335) and the number of productive stems (r = +0.437) had the greatest impact on the yield. During the moisty year (НТС = 1.36), the productivity of barley was significantly affected by a set of indicators of structural elements: plant height (r = +0.890), grain weight from the ear (r = +0.810), the number of grains in the ear (r = +0.806), ear length (r = +0.774) and the mass of 1000 grains (r = +0.640). When analyzing the elements of the crop structure, a significant dependence (r = +0.674) was established between the length of the ear and the number of grains in it. A negative correlation has been established between the productive bushiness of plants and the mass of 1000 grains, between the number of productive stems and the mass of grain from the ear. It has been found out that the slightly varying traits include the number of grains in the ear (Cv = 4.8%) and the length of the ear (Cv = 9.6%). It has been revealed that the yield of the studied varieties and promising lines has a low variation over the years of Cv = 8.8%, which indicates to the effectiveness of breeding work on developing barley varieties with high and stable yields.

Productivity of any crop is the potential of the variety when interacting with environmental factors, and especially meteorological ones. Losses due to unfavorable conditions in some years can be up to 50-65,0 %. The purpose of the work was to identify how the productivity of Sudan grass green mass varied through the years with different meteorological conditions, which factors had the greatest effect on it. The study was carried out in 2012-2021 in the conditions of Rostov region. The soil of the plot was ordinary carbonate chernozem. The object of the study was the Sudan grass of Alisa variety, introduced into the State List of Breeding Achievements in 2019. Differences in sowing dates (I-II decades of May) had no effect on green mass productivity and the time of grain maturing. The Sudan grass green mass productivity varied significantly from 36 t/ha to 43 t/ha through the years of study. The year of 2021 was more favorable both in temperature and moisture supply for the formation of the first cut of green mass, and the year of 2018 was favorable for the formation of the second one. The first cut of the green mass was more important and productive. The second cut productivity in 2018 was 84.5 % of the first cut and 45.8 % of the amount of both cuts. In 2021, 35,0 % of the first cut and 26.5 % of the total productivity. The correlation analysis has confirmed that green mass productivity has a close positive correlation with the amount of precipitation (r = 0.79) and a mean negative one with the average air temperature during the vegetation period (r = -0.59).

The purpose of this work was to evaluate the stability and plasticity parameters of 30 samples of the collection of Eastern galega (Galega orientalis). The research was carried out on the Polar OS VIR (Apatity, Murmansk region) in 2005-2009. Observations and records were carried out according to the VIR guidelines. Statistical data processing included the calculation of stability and environmental plasticity indices. During the years of the research, various conditions were formed for the manifestation of the studied traits: favorable – according to winter hardiness and foliage in 2005 (environment index +4.1 and +6.1), plant height and seed productivity – in 2009 (+24.8 and +10.9), bushiness – in 2006 ( +7.4), fodder productivity – in 2008 ( +0.33); unfavorable – for winter hardiness in 2008 (-2.9), height and feed productivity in 2006 ( -23.8 and -0.44), bushiness, leafiness and seed productivity in 2007 (-5.0, -3.0 and -6.4). The variability of the stability parameter in plant height and yield of air-dry mass is average, in bushiness, leafiness and seed yield is high, in winter hardiness is very high. The studied accessions are fairly evenly distributed among groups with low, optimal and high values of the stability parameter. Valuable material for breeding are k-55536 and k-55537 accessions naturalized in the Murmansk region with high feed (19.5±2.32 and 19.8±1.94 t/ha) and seed (6.45±0.371 and 6.85±0.282 c/ha) productivity, stability of the seed yield index, responsiveness to improving growing conditions according to the yield of air-dry mass.

Data on the influence of abiotic and anthropogenic factors on the formation of crop yields are important for developing the system for production process managing. The studies were carried out in 2012-2019 on the basis of agroecological stationary experiment aimed at investigating the effectiveness of long-term use of mineral fertilizers (N0P0K0, N65P50K50, N100P75K75) and an integrated plant protection system. Weather conditions turned out to be the most significant among all factors affecting the yield of spring rapeseed Oredezh 4 in the North-West region of the Russian Federation. Rapeseed plants show increased sensitivity to moisture and heat supply conditions in the first half of the growing season. At the same time, during the most of the growing season of the crop and especially at the initial stages of ontogenesis the rainfall has a positive effect (r = 0.43…0.67, р ≤ 0.05), and temperature has a negative effect on rapeseed yield (r = -0.44…-0.50, р≤0.05). The integrated plant protection system was more important in the formation of the spring rapeseed crop (19.8 %) than the application of mineral fertilizers (2.2 %). According to the results of all the necessary protective measures, the averaged value of the preserved spring rapeseed yield over the years of the research was 1.04 t/ha (90 %), in the years of mass reproduction of the cabbage moth it reached 0.96 t/ha (213 %), in the years of strong development of Alternaria – 1.46 t/ha (248 %). In the absence of protective measures, the application of fertilizers, as well as the cultivation of spring rapeseed in general, becomes impractical. The combined use of mineral fertilizers and plant protection products in spring rapeseed sowings ensured the formation of a seed yield of 1.97-2.13 t/ha, which exceeded the control (N0Р0К0, without means of protection) by 1.06-1.22 t/ha (117-134 %).

In the natural and climatic conditions of the Novgorod region, the ecological regimes of lands drained by various open drainage structures were studied: channels through 70 m (control), runoff hollows in combination with the strips of cultivation, reclamation, and closed drainage. During the operation (1992-2021) of open drainage structures, the agrochemical state of soils changed: the exchange acidity decreased; the humus content increased by 2-3 %, with the exception of a combination of hollows with a reclamation strip (a decrease of 1.5 %); the content of mobile phosphorus and potassium decreased. The formation of groundwater regimes and moisture reserves on drainage systems depends on meteorological conditions, which in the last 5 years have been very diverse: from slightly arid (2020, HTC = 1.1) to excessively moist (2017, HTC = 2.65). The systems of runoff hollows in combination with the reclamation strip provided the lowest groundwater level, while in an extremely wet year they did not rise into the arable horizon. The most favorable moisture regime of the root-inhabited soil layer in excessively humid 2017 and subsequent years was noted on systems of runoff hollows with closed drainage in combination with reclamation strips. During dry periods, which are usually June-July, a lack of moisture in the root layer of the soil was observed on experimental systems of runoff hollows in combination with cultivation and reclamation strips. The most acute moisture deficiency in these periods (0.45 full capacity) was noted on systems combining runoff hollows with cultivation strips. The most favorable soil moisture regime (0.65-0.85 full capacity) was in the combination of hollows with closed drainage and a reclamation strip. The formed new ecological regimes of the soils drained by the hollow-strip method had a significant impact on the hay yield of perennial grasses (Phleum pratense, Festuca pratensis). The increase in yield compared to the control averaged 0.3-0.6 t/ha over 5 years.

Research on the use of mineral fertilizers considering the intrasoil variability of agrochemical indicators in the sowings of Sudanese grass of Kinelskaya 100 variety was carried out in 2011 and 2017 in two fields of crop rotation deployed in time (pure fallow - winter wheat – spring wheat – spring wheat – Sudanese grass – spring barley) on leached heavy loamy chernozem (humus in the arable layer – 5.2-7.1 %, nitrate and ammonium nitrogen 6.5-16.9 mg/kg of soil, mobile forms of phosphorus – 83-201 mg/kg of soil and exchangeable potassium – 91-198 mg/kg of soil) in the forest-steppe regions of the Euro-North-East of the Russian Federation (The Republic of Mordovia). The scheme of the experiment included 3 variants with fertilizers (planned yield of green mass of Sudanese grass 20.0 t/ha): control (without fertilizers); average dose of fertilizers (N89P33K30 – in 2011, N92P35K28 – in 2017); differentiated doses (N73-99P21-31K23-32 in 2011 and N70-103P24-40K20-21 in 2017). The experiment was based on the principle of a split plot, where plots of the 1st order were reserved for variants with fertilizers, and plots of the 2nd order (5 plots in each repetition) were used to determine the variability of intrasoil fertility and fertilizer application. On average, among two crop rotation fields, the highest yield of Sudan grass (25.1 t/ha) was obtained in the variant with differentiated use of fertilizers, that was significantly higher than the control (49 %) and 10 % higher than in the variant with average doses. The application of fertilizers considering the heterogeneity of soil fertility ensured the smallest range of variation of the yield (4.4 t/ha) among the plots of the testing ground with an insignificant level of variation coefficient (V = 6 %). The use of fertilizers had a positive effect on the collection of dry matter, feed units and digestible protein per 1 ha. According to these indicators, a significant advantage was observed for the variant with differentiated doses, which also provided the highest level of production profitability (122.3 %).

The research was carried out in a long-term stationary experiment, launched in 1978 on light gray forest soil in the conditions of the Nizhny Novgorod region. In 2020-2021, the effectiveness of various doses of mineral fertilizers (N0P0K0, N15P40K60, N30P80K120, N45P120K180) was studied against the background of liming when laying the experiment (in doses 0; 0.5;1.0;1.5; 2.0; 2.5 of hydrolytic acidity) on the yield of meadow clover Martum of the 1st and 2nd years of use. It has been established that the studied lime doses introduced in 1978, by August 2021 had not affected the change in agrochemical parameters of light gray forest soil (acidity, content of mobile forms of phosphorus and potassium, humus) and the yield of meadow clover of the 1st and 2^nd year of use. A long-term use (1978-2021) of single and double doses of mineral fertilizers did not provide the accumulation of humus, mobile forms of phosphorus and potassium as compared to their initial content in arable layer of light gray forest soil. Increased content of mobile forms of phosphorus and potassium (Р2О5 per 34.1 mg/kg, К2О per 22.3 mg/kg) was observed by long-term application of three-fold doses of mineral fertilizers. Application of mineral fertilizers in a dose of N45P120K180 enabled to obtain 36.5 and 37.9 t/ha of green mass during the 1^st and the 2^nd year of use and the highest total yield of 74.4 t/ha that is 12.0-22.2 t/ha higher than the control and all the rest variants of mineral fertilizers application.

Inbreeding is an integral part of breeding work today. However, its effect on the economically valuable traits of animals is not identical. The research was carried out in LLC "Вreeding plant «Pushkinskoe» Bolsheboldinsky district of the Nizhny Novgorod region. The data have been obtained from the primary zootechnical records and database «SELEX» – Dairy cattle (n = 950). The animals were divided into 4 groups depending on the degree of inbreeding. Cows with the close degree of inbreeding had the maximum milk yield (9877.9 kg), those with the mild degree had minimal milk yield (9338.11 kg). An increase in the degree of inbreeding had a negative effect on the fat content in milk, which led to its decrease from 3.85 % in the group with outbred animals to 3.64 % in the group with the close degree of inbreeding. There were no significant differences in the protein content in milk between the groups. The lactation stability coefficient decreases as the degree of inbreeding increases. The variability coefficient of milk yield in animals with the close degree of inbreeding is lower than the other groups (10.53 %), the coefficient varies within 5 % according to the fat content in all groups and in terms of protein content in milk within 1.3-2.2 %. Distant and mild inbreeding has a weak positive relationship with milk yield (r = +0.015 and +0.028), close inbreeding leads to its decrease (r = -0.098). Inside the groups, having inbred connections, аn increase in the inbreeding degree leads to a very slight increase in fat content (r = +0.016-0.129) and the lactation stability coefficient (r = +0.063-0.164), the influence of the degree of inbreeding on the protein content in milk is not identical. The relationship between milk yield and fat content in outbred animals is weakly positive (r = +0.26), in cows with mild and distant degree of inbreeding is weakly negative (r = +0.057-0.121), in the group with a close degree it becomes closely negative (r = - 0.677).

The object of the study is a probiotic Rumit produced by Biotrof Ltd., which can be added to the diet of milk-fed calves. It is developed on the basis of cellulolytic bacteria. In order to assess the effectiveness of the probiotic use there has been conducted a scientific and agricultural experiment on the basis of the agricultural production co-operative Kolkhoz Andoga of the Kaduysky district, Vologda region since March to June 2021. Studied were 20 calves of black-and- white bred aged 1.5-2 months divided according to the principle of paired peers into two groups: a control and an experimental. The experimental group was given the probiotic Rumit in the amount of 15 g/head/day during 90 days as a supplement to the basic diet. The data on live weight obtained in the course of the study indicate that the use of the probiotic in feeding calves has led to an increase in gross growth to 74.2 kg, that has provided a 3.8 % reduction in feed costs per unit of output.

The article presents a study of the influence of methods for calculating particle trajectories in the pneumatic separation channel (PSC) on the design parameters of the separation chamber (length and height of the exit window), completed in 2013-2021. The field of air flow velocities and trajectories of spring wheat seed material components in the separation chamber of fractioning pneumatic seed separator was constructed. The initial data for the calculation were the information obtained earlier when calculating the trajectories of particles in the PSC by various methods. The location at the outlet of the channel, the value and direction of the particle velocity vectors were determined by computer modelling using the Solidworks Flow Simulation software package and two experimental and theoretical methods. They took into account the real velocity field of the air flow with and without grain load. The obtained values of the design parameters are compared with the results of experimental studies of the separation chamber. It should be noted that the methods of calculating the trajectories of grain impurity particles have a significant impact on the length of the separation chamber and the height of the exit window. The maximum length of the separation chamber of 0.75 m will be required for computer modelling of the velocity field in the PSC. Much smaller values of 0.50 m and 0.45 m will be required when calculating the trajectories of particles in the PSC using the velocity field obtained by experimental and theoretical methods. During the experimental study of the separation chamber during the cleaning of wheat seeds, the optimal length of the separation chamber was determined to be 0.55 m with an exit window height of 0.30 m. Thus, the values of the design parameters of the separation chamber obtained by experimental and theoretical methods are the closest to experimental data, which makes it possible to recommend them for use at the design stage of pneumatic separators.

One way to improve the mixing efficiency of protein-mineral-vitamin additives for cattle diets is to fluidize the material. The aim of the study is to define theoretical dependences between the speed and energy characteristics of the formation of a fluidized bed on the physical and mechanical properties of mixing substances and on structural and kinematic parameters of the mixer. The research was carried out in 2021. A coefficient of structural and mechanical resistance of the disperse many-component system was introduced to clarify the characteristics of additives mixing in the fluidization mode. The obtained equations described the particle velocity and the energy consumption for the particle flow in a fluidized bed influenced by a blade mixer. Next step was to reveal the effect of the layer porosity and the mixer blade angle on the particle velocity in the mixture. The velocity loss equation was solved as a graph for the value of 5 m/s at the blade edge. The variation in the layer porosity had a significant effect on considered parameter. The greatest velocity loss exceeded 4.5 m/s observed at the smallest porosity of 0.14 and the biggest blade angle of 75º. The smallest loss was below 0.5 m/s at the largest porosity of 0.34 and the smallest blade angle of 15º. Thus, the decrease in the particle velocity by 10 to 90 % was observed in the considered coordinates.