Mathematical simulation of agricultural crop yields is based on the physical principle of causal interactions balance in a closed physical system. The conditions for model verification are determined, allowing to obtain objective and reliable findings. It is noted that empirical equations representing the dependence of crop yields on crop-forming factors in the form of polynomials of any degree, obtained using the multiple nonlinear regression method, are valid only for the conditions of a specific field experiment. Using them, it is impossible to carry out theoretical generalizations that would allow developing these particular solutions into a generalized mathematical model. It is shown that mathematical model of yield, presented in multiplicative form, can include an unlimited number of yield-forming factors. Atmospheric precipitation was used as a factor characterizing the moisture supply for plants in case of no irrigation. The validity of the developed solution is confirmed by 13 years of data on the yield of sugar beet (NZ-type hybrid) cultivated in Belarus at the State Agricultural Institution “Molodechno Variety Testing Station”. The mathematical model of yield is presented in dimensionless form; all blocks of factors of this model are similarity criteria. This allows to compare the results of mathematical simulation of yield of any agricultural crop on soils with any agrochemical properties. Such an analysis cannot be carried out with the results of calculating yields using the formulas of private mathematical models of agricultural crop yields in the form of algebraic polynomials.

Collections of plant genetic resources are the guarantor of the preservation of both natural biological diversity and breeding achievements. Basically, genetic collections consist of seeds and, proper storage in optimal conditions is a necessity (it frees them from frequent reproduction associated with material and labor costs). It is necessary to search for optimal natural conditions for long-term storage of seeds, because in case of emergency situations of a technogenic nature, they will be the most vulnerable. A long-term experiment of long-term storage of agricultural plant seeds in permafrost conditions is being carried out. The aim of research is to find optimal and safe conditions for long-term storage of seeds and grain for both sowing and food purposes, and to study the conditions of natural storage facilities for creation of strategic reserves of seeds and food. In 2010, consignments of seeds of the main grain crops were put into storage (spring wheat, spring barley, winter rye and oats); in 2016, a seed collection of 26 varieties of 8 types of vegetable crops was laid. Meteorological observations were carried out, thermographs and hygrographs were used in the storage. The first sample extraction took place after 6 years of storage. Laboratory analysis of seed quality was carried out using the following standard methods: GOST 12036-85; GOST 12038-84; GOST 12041-82; GOST 12042-80; and GOST R 52325-2005. The results showed high viability of seeds of grain and vegetable crops. Seeds of all samples of grain crops met the requirements for reproductive seeds (germination over 87 %) according to GOST R 52325-2005. Seeds of 17 samples of vegetable crops retained germination at the first-class level in accordance with the requirements of GOST 12038-84. Long-term meteorological observations show a gradual warming of the Arctic climate due to relatively high summer temperatures. In general, the continentality of the climate is growing. The experiment continues, most of the above seed batches remain in storage, further expeditions with the extraction of samples are planned for 2025, 2035 and 2050. The obtained weather data indicate an increase in the continentality of the Arctic climate and its general warming. The data obtained on the viability of cereal grains and vegetable seeds during long-term storage show the effectiveness of using permafrost conditions for this purpose.

Anthracnose (Colletotrichum acutatum) is a dangerous strawberry disease. In the Eurasian Economic Union, C. acutatum is a quarantine pathogen. Therefore, an important aim is identification and creation of new strawberry forms with genetically determined resistance. Use of diagnostic DNA markers of target genes’ resistance alleles will increase reliability of identification and effectiveness of breeding process. The purpose of this study was molecular screening of anthracnose resistance allele Rca2 in strawberry varieties and selected seedlings to identify forms with genetically determined resistance to C. acutatum. The objects of the study were 1st variety of strawberry hybrids (F. × anashata Kantor.) and 53 genotypes of garden strawberry (F. × ananassa Duch.): 38 varieties and 16 selected forms. Molecular screening of Rca2 resistance allele was carried out using the DNA marker STS-Rca2_240. To control the PCR progress, the marker STS-Rca2_240 was multiplexed with the marker EMFv020. As a result of the analysis, the marker fragment of the Rca2 gene was identified in 14 (25.9 %) of the 54 analyzed strawberry samples. Among the strawberry varieties, the marker is present in 8 forms (21.1 %), and among the selected forms – in 6 samples (37.5 %). In the remaining analyzed strawberry samples, Rca2 gene is represented by the rca2 allele in homozygous state. Among the Russian strawberry varieties, the Rca2 gene is present in the variety of Dar (heterozygous combination of alleles). Among the foreign strawberry forms, Rca2 gene was identified in the varieties of Aprica, Florence, Laetitia, Malwina, Monterey, Portola and Selva (homozygous (Rca2 allele) or heterozygous combination of alleles). Among the analyzed strawberry selected forms, Rca2 gene in heterozygous form was identified in hybrids 2/1-24 (Quicky × Olympia), 3/9-28 (Florence × Faith), 4/7-10, 4/7-19 (Asia × Aprica), and 5/2-26, 5/2-32 (San Andreas × Monterey). These genotypes are genetic sources of resistance to anthracnose and can be used in marker-assisted breeding. 

Human granulocyte–colony stimulating factor (GCSF) is one of the pharmacological proteins that can be isolated from the milk of transgenic (TG) animals. The plasmid containing the human GCSF gene under the control of regulatory elements of the bovine β-lactoglobulin gene and the reporter green fluorescent protein (EGFP) gene under the cytomegalovirus (cmv) promoter were obtained. The use of the selected promoters ensures tissue-specific expression of the target protein in the mammary gland of the TG producing animal and a high level of early expression of the reporter protein in eukaryotic cells, which makes it possible to detect TG embryos at the cultivation stage and perform their preimplantation selection. Testing of the gene construct effectiveness was carried out on TG rabbits obtained by microinjection into the male pronucleus of zygotes. It was concluded that GFP is toxic to embryos in the early stages of development due to overexpression of the EGFP gene under a strong cmv promoter. The TG female rabbit (F0) was obtained, in which the level of human GKSF in milk and blood serum was assessed by the ELISA method. Of the 22 baby rabbits obtained from her in four kindling, two were transgenic. Offspring (F1) was obtained from the TG male F0, 56 % of which were males, of which 88 % were TG and did not differ from ordinary rabbits in terms of health. Among females, TG was 10 %, and they died within two weeks after birth.

In the Republic of Belarus, crop yields have increased 3.5–5 times over the past 60 years due to the combined result of work in the field of breeding, mechanization of fertilizers and chemical plant protection products application, which is a significant achievement of science and practice [1, p. 28]. One of the main criteria for evaluating the effectiveness of mineral fertilizers is considered to be the payback of 1 kg of NPK, which should be at least 8 kg of grain or 10–12 feed units by all crops on arable land [2, p. 113; 3]. To achieve such results, spreaders must perform high-quality distribution of mineral fertilizers within the established agrotechnical deadlines. The criterion for assessing the quality of the distribution of mineral fertilizers over the field area is the coefficient of variation, which is defined as the ratio of the standard deviation to the average dose. In addition to uniform distribution over the field area, high-quality incorporation of mineral fertilizers with tillage tools is also essential. As for the timeliness of applying the specified doses of fertilizers within the established agrotechnical deadlines, the most important factors here are the availability of equipment at farms during the busiest period and provision of high-performance fertilizer spreaders. It should be considered, that agricultural chemicalization machines are used from early spring to late autumn, and their annual load exceeds the same indicator for other agricultural machinery. In addition, the operation of fertilizer spreaders involves interaction with aggressive media, which imposes appropriate requirements to ensure their reliability. It should be noted that currently unmanned aerial vehicles are beginning to be actively used to introduce chemicals [4, p. 2]; publications on the development and testing of nanofertilizers are increasingly appearing in the scientific literature [5, p. 319]. In this regard, in order to determine further trends in the improvement of technical means for fertilization, it is necessary to analyze the main stages of the development of these technical means and identify the distinctive stages of their improvement.

A promising trend for development of optical-electronic methods and technical means for monitoring the condition of the mammary gland of a dairy cow is presented. A layout has been developed for determining the technical parameters of the tool relative to the thermal field of the cow’s mammary gland. The technical parameters of the tool for contactless identification of cow mastitis using the thermographic method in the conditions of continuous milk production were determined theoretically and experimentally. The viewing angle of the lens of the technical tool in the horizontal plane is α_hor = 33 degrees, in the vertical plane  α_vert = 24 degrees; focal length  f = 0.0075 m; udder viewing area in the horizontal plane S_hor = 0.57 m, in the vertical plane S_vert = 0.42 m; minimum element of udder resolution in the horizontal plane  Δ_hor = 0.0037 m, in the vertical plane  Δ_vert = 0.0047 m; the rational distance from the lens of the technical tool to the udder is L = 1 m; rational distance from the lens of the technical tool to the floor is H = 1 m; four groups of animals were identified under given temperature conditions: healthy  – animals with a negative kenotest result (–) in the temperature range of [34.6 ºС <T_max < 36.8 ºС]; intermediate – with an intermediate kenotest result (+) in the temperature range of [36.8 ºС < Т_max < 38 ºС]; subclinical – with a subclinical stage of mastitis according to kenotest (++) in the temperature range of [38 ºС < Т_max< 39 ºС], and clinical – with a pronounced stage of mastitis according to rapid test (+++) in the temperature range of [39 ºС < Т_max < 40.5 ºС]. A design and technological layout for incorporating the thermographic method for diagnosing mastitis into a production line for milking cows is presented, and a systematic assessment of methods for diagnosing mastitis is given.

The paper examines modern approaches to the valorization of slaughterhouse tankage using biological and thermochemical processes to obtain alternative energy sources, as well as feed products with high biological and nutritional value to compensate for protein deficiency in livestock breeding. Particular attention is paid to the potential possibilities of using feed products from slaughterhouse tankage for ruminants, with low availability of their biological usefulness to proventriculus symbionts, as well as the possibilities of using endocrine raw materials for correction of metabolic processes in the body. It has been determined that the efficiency of meat processing plants should be determined by the completeness of processing of raw materials. Application of modern physical, chemical or biotechnological methods can contribute to the pro- cessing of waste by-products (food ingredients, biomaterials, pharmaceuticals, etc.), with obtaining added value, being an economically advantageous part of the production process. Creation of closed-cycle technologies of large-tonnage production processes for the processing of by-products of meat production (in particular, slaughterhouse tankage) can be a potential source of high-value feed products for the needs of animal husbandry, as well as contribute to reducing the negative impact on the environment. Recycling of slaughterhouse tankage should be considered as a permanent raw material source of feedstuff, while solving a number of environmental problems of utilization, which is of great scientific and practical importance.