The article discusses issues related to the effectiveness of diagnostics of persistent infections. Using PRRS as an example, the relationship between “disease stages” and “diagnostic stages” is discussed on the basis of a meta-analysis of data from diagnostic studies (n = 4307 results) presented in refereed scientific papers to understand the key points. Despite the ongoing improvement of diagnostic methods, none of them individually can be recognized as the only correct decision: the choice of the type of sample and test for research depends on the specific task. In most cases, to establish the true picture of an epizootic, it is necessary to use several research methods and / or types of samples.

The problem of prevention and treatment of gastrointestinal diseases of infectious etiology of calves is still relevant. Recently, bee products (honey, bee venom, bee parchment, propolis, royal jelly) have been used for this purpose. Taking into account the unique properties of beekeeping products, we have developed a new biologically active agent based on modified bee parchment. The developed product is made by alkaline hydrolysis of 3-4 % solution of sodium hydroxide of bee parchment and contains a complex of biologically active substances. In order to accelerate the study of the effect of the developed product on living organisms, a model of using the ciliated protistic organism Paramecium caudatum, inhabiting freshwater reservoirs, was proposed. The aim of the study was to study the biocidal properties of the developed agent of the biological model. The study of the effect of a new agent based on modified bee parchment was carried out according to the methodological recommendations “Screening of bio-stimulating and biocidal substances (adaptogens, bactericides and other drugs)” on a model of a free-living infusoria slipper Paramecium caudatum. As a result of the study, it was found that the developed agent has pronounced biocidal properties (similar to widely used antibacterial drugs). In order to study the cytotoxic and ecotoxic effects of the developed medium, it is necessary to conduct a number of additional studies to determine their comprehensive effect on protistic organisms as a test laboratory model.

Relevance and methods. The article considers the experience of studying the effect of crossing Kalmyk sheep and dorper sheep-breeders in order to increase meat productivity. Crossbred rams of the experimental group had better indicators than rams in the control group in terms of live weight, depending on the conditions of pasture maintenance. Dagestan has a fifth of the Russian sheep and goat population and a quarter of wool production. In this area sheep breeding has a unique specificity, twice a year cattle are driven from summer to winter pastures and back. The distance between the pasture areas is more than 570 km. Of the total number of sheep, 71.5% falls on the Dagestan mountain breed.

Results. To further increase the level of profitability of fine-wool sheep breeding it is of great importance to develop research on the economic and useful characteristics of young Dagestani fine-wool sheep and their crossbreeds with Russian meat merino sheep, depending on the driving and pasture system of keeping.

The relevance of research. Currently the methodological base for assessing the breeding qualities of bulls-producers of dairy and milk-meat breeds by the quality of offspring is carried out in accordance with the Instruction approved by the MA of the Republic of Kazakhstan in 2007. The principle of assessment, set out in the Instruction, is to compare the phenotypic indicators of the offspring with each other according to the principle of “peer daughter”. Although this document was approved already in the XXI century, nevertheless the basic approaches, which were put the basis, were developed in the first half of the last century and currently do not correspond to modern scientific principles. At the same time the world leaders in the field of breeding in dairy cattle breeding have been successfully using the BLUP method in breeding practice to assess the breeding qualities of animals for decades. This principle of assessing the breeding value of bulls is the most theoretically grounded and allows you to obtain results comparable to each other. Therefore the development and optimization of the equations of mixed BLUP models is extremely relevant for the conditions of the Republic of Kazakhstan from both scientific and practical points of view.

Material and research methods. The material of the research was the data on the phenotypic indicators of the signs of milk productivity of first-calf cows of the Holstein black-and-white breed obtained from the republican database of the Republic of Kazakhstan for 2016-2017. As a criterion for choosing the best equation the residual variance values of each model under study were used.

Results: when improving the method for assessing bulls-sires of the Holstein black-and-white breed according to the quality of offspring, out of the four studied equations of the mixed BLUP model one equation was optimized to assess the breeding qualities of the sires. In principle, to assess the breeding qualities of producers by the quality of offspring it is possible to use any of the models under consideration, since the established differences for all analyzed characteristics of milk productivity are insignificant (no more than 6%)

Mineral additives in the form of inorganic salts such as sulfates or oxides of various metals are poorly absorbed by the body. At the same time, the assimilation of salts of organic amino acids, which are more similar in structure to a living cell, occurs in a much greater volume, indicating that many organic forms of trace elements are more accessible than inorganic ones. The analysis and study of the effect of the mineral complex based on L-aspartic acid on the microbiological state of the contents of the rectum of pigs was carried out. The use of asparaginates in the diets in an amount of 10% contributed to the normalization of the microbiocenosis of the large intestine of animals, due to the creation of the most optimal conditions for the development of normal flora (lacto-and bifidobacteria) and a simultaneous slowdown in the reproduction of opportunistic microflora.

Relevance. Modern livestock breeders face an important task of producing organic products, in Russia this is regulated by the Federal Law “On Organic Products” (from 01.01.2020), it allows producers to enter in the state register and mark the products with the “organic” sign. There is a problem of deterioration of the quality of milk, low content of fat, protein, SOMO, deficiency of macro- and microelements, vitamins, which is associated with a violation of the proper feeding of animals. The use of innovative technologies for the activation and modification of silicon-containing minerals (diatomite and zeolite clinoptilolite) enhances their properties. This makes it possible to use them as an adsorbent, an ion exchanger and a source of readily available silicon and other mineral elements to produce high-quality organic products.

Methods. To achieve this goal in the Ulyanovsk region we organized a production experiment in the conditions of a dairy farm of “Agrofirma Tetyushskoe” for a duration of 100 days. Three groups of 50 cows were formed: 1 — control, received only the basic diet (BD), 2 — experimental (BD + supplement based on modified zeolite enriched with amino acids), 3 — experimental (BD + supplement based on modified diatomite enriched with amino acids). The supplement was given once a day in the morning in a mixture with mixed feed, the input rate was 250 g/head/day. For the physiological experiment 5 analog cows were selected in a group. To enrich the minerals a complex of plant-derived amino acids of high purity and biological activity was used.

Results. The intake of additives based on silicon-containing natural minerals (zeolite and diatomite), processed with innovative technologies and enriched with plant-based amino acids, increases the level of animal productivity and ensures the yield of organic products of high-quality. It has a prolonging effect.

Relevance. Introduction and variety study of flower and ornamental crops is one of the main tasks of botanical gardens, which aims to expand the promising assortment for domestic floriculture.

Results. In the period from 2018 to 2020 varieties of hybrid iris (Iris x hybrida hort.) from the garden group “tall bearded” were studied in the Stavropol Botanical Garden. The presented 13 varieties belong to foreign selection. Basically, the varieties are characterized by medium or early flowering periods with an average duration of 11-15 days. In the course of the study, biometric characteristics, the economic and biological properties of the varieties were analyzed. The varieties with the longest duration and productivity of flowering were identified. The ability to bear fruit, which is important for further breeding work, was noted in three varieties: Autumn Circus, Pallida Variegata, Immortality. The main disease that harms the studied culture is heterosporiosis. The most resistant to diseases are the varieties Afternoon In Rio, Bye Bye Blues, Pallida Variegata (up to 10% damage). The detected pests (flea beetle, aphid, mole cricket, etc.) generally cause minor damage to the studied plants. In the assessment of decorativeness, 11 parameters were analyzed using a 100-point scale and taking into account the conversion factor. The color, size, shape of the flower, aroma, inflorescence, duration and abundance of flowering, resistance to adverse weather conditions, decorative vegetative part of plants, originality, condition of plants were taken into account. As a result of the variety study, 9 highly decorative varieties were identified: Bye Bye Blues, Stardock, Autumn Circus, Lotus Land, Power Point, Good Day Oregon, Lorilee, Conjuration, Afternoon In Rio.

Agriculture of the Northern regions specializes in animal husbandry, in this regard an urgent problem of crop production in the conditions of the Northern regions of the Russian Federation is the creation of precocious, high-yielding varieties of grain crops for fodder purposes. The article reflects the selection achievements in grain crops over the past seven years. The presented new varieties combine high yield, increased environmental plasticity, and have the ability to reduce their productivity to a lesser extent when cultivated in the harsh conditions of the Northern region. Breeding work conducted at the laboratory of crop production of the Primorskiy filial FGBUN FICKIA RAN - ArhNIISKH in 2005-2019, in breeding semipolar rotation in accordance with the "Guidelines on the selection of barley and oats" (2014), methodology of State Commission for testing of agricultural crops (1985). The digestibility of winter rye dry matter was determined by in vitro method on an artificial stomach. Statistical processing of experimental results was performed using the AGROS version 2.07 selection and genetic software package. Results of the study. As a result of selection work, precocious productive varieties of grain crops of the feed direction were bred and included in the state register. Bereginya — new-generation winter rye variety, universal use, with a low content of water-soluble pentosans in the grain. The variety has been included in the State register of selection achievements since 2013. Variety of spring barley Tausen — feed direction, resistant to environmental stress factors, high-yielding, resistant to lodging and pathogens (dusty smut, spotting). It has been included in the State register of selection achievements since 2014. Spring barley variety Kotlassky — feed direction precocious, productive, adaptive to adverse environmental factors, for obtaining concentrated feed for livestock and poultry. It has been included in the State register of breeding achievements since 2019. Arhan spring oat variety — environmentally plastic adapted to changes in soil and climate conditions, immune to dusty smut, combines a high yield of grain and green mass. Since 2020, it has been included in the State register of selection achievements.

The study of coastal and aquatic tropical flora as part of the conservation of world biodiversity is the main purpose of research in botanical gardens. Conservation of plant collections involves a continuous process of plant reproduction. This means searching for ways of reproduction that are most effective for a particular group of plants and optimal timing of obtaining adult specimens. Generally accepted methods for seed (T. A. Rabotnov) and vegetative reproduction were used; for Nymphaea x daubeniana (viviparous water lily) was used the Sean Stevenson method. During 2017-2020 in the Stavropol Botanical Garden was conducted an experiment to study the reproduction of tropical water lilies in protected ground conditions. An artificial pond with a water mirror area of 85 m² is located in a greenhouse, heated from October to April. Cross-pollination occurs during the mass flowering period (June-July, with illumination up to 93.5•10³ kilolux), seed maturation occurs within 58±4 days, and seedlings bloom in 7-8 months. The moderate correlation was established between the soil composition and the intensity of flowering (p < 0.4) and the formation of nodules (p < 0.4). The absence or short flowering of water lily varieties and the mass of nodules (150-300 g) contributes to the formation of more planting material (up to 12 or more pieces). The vegetation period for 99% of the studied plants is 1478±26 days, for the species Nymphaea gigantea it is 887±15 days. Regardless of the species and variety of tropical water lilies, reproduction by daughter nodules formed at the base of the main tuber occurs throughout the growing season.

The article provides data on the study of varieties in a collection nursery in the conditions of Central Yakutia. For the period 2015-2017 in collection nurseries 292 specimens of various origins were studied. The predecessor is steam. Sowing was carried out at the optimal time for the culture on May 22-26. The “Tammi” variety, zoned in the republic, was used as a standard. The variety is ultra-early ripening, the growing season is from 58-66 days. The mass of 1000 grains is 32-37 g. Average yield in favorable years is up to 20-25 c/ha. Drought resistance is average. The standard was plated every 30 samples. The evaluation of the studied samples in the field was carried out according to such characteristics as the duration of the growing season, yield, resistance to lodging, productive tillering, grain content, grain productivity. The plants were harvested by hand followed by hand threshing. The duration of the growing season for all varieties over the years of research varied on average from 67 to 80 days or more. The following early ripening varieties were identified: Polar (Norway), Grosso (Netherlands), Rajsa (Sweden), Sobolek (Russia), Zolotnik (Altai region), Svyatogor (Kirov region), Stimul (Krasnodar region), Symko (Canada), Stacey (Canada), Chervonets (Irkutsk region), Beacon (USA), Tandem (Kirov region), Courier (Krasnodar region). Based on the results of the study, the best varieties were identified by yield (Tandem, Beacon, Sobolek, Svyatogor, Rajsa, Courier), by the weight of 1000 grains (Zolotnik, Sobolek, Svyatogor, Symko), by productive bushiness: Tandem (pallidum), Sobolek (ricotense), Stimulus (nutans), Courier (nutans), Svyatogor (nutans). Based on the study data, the source material was extracted and selected for further use in the hybridization of new early maturing, highly productive varieties.

The current paper has presented the estimating results of the effect of vegetation conditions on a leaf area index, preservation of chlorophyll pigment and productivity of the winter common wheat samples developed by the ARC “Donskoy”. The study was conducted in the laboratory of plant physiology in 2017-2020. There has been used the following methodology: the leaf areas were determined by the Nichiporovich's method (1955), the leaf area index during the periods of ear formation and flowering was estimated according to S.A. Tarasenko (2015). The chlorophyll content in the leaves of winter wheat varieties was assessed by the Shmatko's method (1976). The study results have identified that the leaf area indices and the chlorophyll content in leaves during the vegetation period changed according to the drought resistance degree of plants and depended mainly on the root moisture supply and on the studied genotype. In the conditions of insufficient moisture supply the varieties Krasa Dona, Asket, Etyud and Volny Don formed the maximum values of a leaf area index and preservation of chlorophyll pigment.

The article presents research materials devoted to evaluating the technology of sunflower cultivation with strip basic soil cultivation using elements of Strip-till technology in comparison with the recommended one. The originality of the approach to the cultivation system, in comparison with the classic Strip-till technology, consists in preliminary surface stubble cultivation in two tracks, which retains productive moisture, provokes more intensive germination of weeds, and, accordingly, a more effective effect of subsequent spraying of the stubble with glyphosate. It was found that during the growing season of sunflower with abnormally harsh climatic conditions in 2020 (GTC = 0.07) the soil density in the flowering phase of sunflower was 1.30-1.32 g/cm³, with low moisture reserves in layer 0-100 cm both in spring (57 and 65 mm, respectively) and in bloom (5 and 16 mm, respectively). Applying the fractal dimension method with the calculation of the development index of the root system D, it was found that the harder the agrophysical parameters were during the period of plant development, the less intensively the roots developed: at GTC = 0.22, the D index with the recommended technology and Strip-till technology was 1.63 and 1.76 units respectively, and at GTK = 0.07 — 1.46 and 1.51 units. The low yield of sunflower is associated with a deficit of productive moisture in the summer-autumn period of 2019 and 2020, with a lower reserve of 23 and 102 mm from the long-term norm; nevertheless, a significant increase in the yield of sunflower over the years of research was established by 0.96 and 0.14 tons/ha when cultivating a crop with strip tillage based on the introduction of elements of Strip-till technology in comparison with the recommended one, with a decrease in costs by 11% and an increase in profitability up to 136%.

As a result of the research experiment it was established that the highest yield of winter rye grain of 7.3 and 6.3 t/ha and digestible protein of 0.66 and 0.57 t/ha were obtained when applying doses of mineral fertilizers based on the planned yield (background 1) and reduced by 50% (background 2) in relation to background 1 and double use of microbiological fertilizers: in a tank mixture with a pesticide when etching seeds of 2.0 l/t and non-root treatment of crops in the tillering — exit phase at plant height up to 30 cm of 1 l/ha of each preparation. The use of Azotovite and Phosphatovite twice in technological operations allowed to obtain an additional yield of winter rye grain of 2.4 and 2.1 tons per hectare (more than 48%) in relation to backgrounds 1 and 2 respectively. High grain yield and low cost of microbiological fertilizers, as well as their combined use in tank mixtures with pesticides, provided high energy-economic indicators of winter rye cultivation technologies: low energy intensity of production of a ton of grain (less than 2.4 GJ), high energy efficiency coefficient (more than 7.2 units), production profitability of more than 170%.

Relevance. In peasant-farm conditions and conditions of subsidiary plots, with a wide variety of growing times in greenhouses, which are very different in equipment, heating and use, it is necessary to clarify the agro-ecological terms and introduce regulators of the growth and development of cucumber plants. The use of the adaptogen increases the yield. The aim of the research was to consider the economic efficiency from the use of the adaptogen “Epin-extra” on the growth, development and productivity of various varieties of cucumbers when grown in spring-summer film greenhouses of the Megino-Kangalassky ulus of the Republic of Sakha (Yakutia). Research methods were used according to the methods of the State Commission for Testing and Protection of Breeding Achievements of the Russian Federation [7, 8, 9]. The calculation of economic efficiency was carried out on the basis of the financial costs included in the technological map and the actual costs per 1 hectare according to the method of S.V. Melnikov.

Results. As a result of the research it was found that with a two-fold treatment with a solution of Epin-extra, the development of the main phenological phase of flowering is accelerated for 6 days from control (without treatment with an adaptogen). At the same time, the prevalence of such diseases as ascochito decreases to 1.7%, and the prevalence of root rot is 2.5-3.2 times lower with 2-fold processing, depending on the hybrids. The use of the Epin-extra adaptogen solution increases the quality of products -marketability and weight of cucumber fruits. Due to the use in small volumes, ease of use, the Epin-extra solution increases profitability up to 58.1% with double processing on the Stella F1 hybrid and up to 46.4% in the Maisky F1 hybrid.

The importance of rational use of waste from the processing of grapes, fruits, sugar beets and grain crops in the preparation of high-grade feed is noted. In this regard the relevance of the development of effective technical means for mixing liquid or pasty additives with traditional feed is emphasized. An experimental feed mixer with the ability to produce feed mixtures using secondary raw materials of various aggregate states has been developed. The task of the experimental work was to study its performance under various operating modes. As a result of laboratory studies, it was found that with an increase in the rotational speed of the working body from 60 to 120 min^-1 the productivity of the experimental feed mixer increased from 2,0 to 3,3 t/h. With the subsequent decrease in the amplitude of oscillations of the inter-screw cavity (with a decrease in its volume) the increase in productivity slows down.