The article considers the results of the study of grass meal from binary mixtures of chumiza, vetch, pea, sudan grass, mogar in various combinations and their use in the composition of compound feed for fish. The chemical composition of the green mass of chumiza, soybeans and vetch were studied. It was found that both in pure form and in the form of binary mixtures, the green mass of the studied crops contains crude protein from 13.0 to 21.0 %, crude fat from 1.9 to 2.4 %, crude fiber from 34.0 to 37.0 %. Grass meal also contains carotenoids, macro- and microelements that are part of the enzymes of the fish body and thereby accelerate the growth processes of fish and reduce feed coefficients. It has been established that grass meal in the amount of 1.0 % from a mixture of sudan grass and soybeans, chumiza and peas, and chumiza and vetch can be used in the composition of compound feed for rainbow trout and sturgeon fish.

The article considers the results of the effectiveness of compound feed with different energy-protein numbers. The formulas of compound feed for rainbow trout with the energy-protein numbers of 9.6, 7.7 and 6.5 have been developed. It has been established that with an increase in the temperature of the water for growing rainbow trout, the energy-protein ratio decreases, since with an increase in temperature, the trout’s need for protein increases, and the energy costs of the feed decrease. As studies have shown, the maximum absolute and relative growth of rainbow trout was noted in the variant with the use of compound feed with an energy-protein number of 9.6 in the trout diet. Analysis of feed costs showed that the lowest feed coefficient was observed when feeding rainbow trout with compound feed with an energy-protein number of 9.6. It was revealed that a high protein content in the blood serum was noted for the variant of compound feed with an energy- protein number of 6.5, hemoglobin with an energy-protein number of 7.7 and 9.6.

This article presents the results of comprehensive studies of abiotic and biotic conditions of growing senior repair (four-year-olds) of the ide in polyculture in the ponds of the SPU “Izobelino” of the Minsk region (II zone of fish farming). To abiotic factors belong components of non-living nature, such as the chemical composition of water and its physical parameters (temperature, dissolved oxygen concentration, transparency, etc.). Biotic factors include a variety of interspecies and intraspecific relations, in particular interactions with forage organisms, predators, parasites and competitors.

The study included an analysis of the hydrochemical parameters of the aquatic environment, including dissolved oxygen, pH, temperature, and concentrations of ammonium nitrogen, nitrates, nitrites, phosphates, and iron, which were within the normal range and provided favorable conditions for fish growth and development. The study also examined the species diversity and quantitative development of phytoplankton and zooplankton.

The study investigates the morphometric parameters, growth dynamics, and fecundity of Siberian sturgeon (Acipenser baerii) broodstock and replacement stock cultured at the Scientific Research Institute of Fishery in Uzbekistan. Experiments assessed the effects of body weight, total and standard lengths, and feeding regimes on growth performance and effective fecundity. Strong positive correlations were observed between body weight, total length, and fecundity, indicating high adaptability of sturgeon under artificial conditions. The findings support the use of locally produced feed and optimized feeding schedules to enhance productivity and economic efficiency in aquaculture practices.

Studies have been conducted on the accumulation of technogenic radionuclides strontium-90 (Sr⁹⁰) and caesium-137 (Cs¹³⁷) in some fish species of the Vilia River, at sites of water intake and discharge sites of the Belarusian NPP. The activity of accumulation of Sr⁹⁰ and Cs¹³⁷ in the body of fish with different types of nutrition has been studied. An analysis of the results of radiological studies in 2023 showed that the content of radionuclides in the fish of the Vilia River does not exceed acceptable standards and as a food product it is safe for humans. This work represents an important stage in monitoring the environmental safety of reservoirs adjacent to nuclear power facilities. Taking into account the urgency of radiation protection and environmental control issues, special attention was paid to assessing the possible impact of the Belarusian NPP on aquatic organisms. The data obtained allow us to assess the degree of accumulation of radionuclides in the trophic levels of the ecosystem, and also give an idea of the effectiveness of natural mechanisms of self-purification of the aquatic environment. Additionally, the results of the study can be used in further environmental assessments and the development of recommendations for the sustainable use of water resources. Thus, the conducted analysis contributes to the formation of a holistic picture of the radiation background in the studied area and can serve as a basis for making managerial decisions in the field of environmental protection.

The current state of fish resources of a number of small lakes of the Narochansky National Park is considered when organizing paid amateur fishing on them. According to the fishery classification, the analyzed lakes are assigned to three groups (categories): bream-pike-roach (2), perch-roach (8) and crucian carp-tench (2). It is shown that the composition of the ichthyofauna of small lakes is somewhat narrower than in the park as a whole and is represented by 18 species of fish, of which 15 are native ichthyofauna, 3 are commercial invaders. The latter are either used for the purpose of stocking individual reservoirs with fish, or penetrate through water connections from larger stocked lakes. The values of commercial stocks may fluctuate depending on the intensity of fishing and the volumes of stocking, but generally remain within the potential values determined for the corresponding groups of water bodies in the region. The fishing load for each lake, the composition and dynamics of amateur catch at the current stage of operation were studied, the degree of use of fish resources in the conditions of the functioning of the national park was determined, and the growth of the value of amateur catch was shown.

A comparative assessment of hormonal stimulators of maturation of sexual products of female pike perch was carried out using the ecological and physiological spawning method. The effectiveness of using the gonadotropic hormone carp and three synthetic preporations surfagon, gonaderil and ovopel was compared. It is these drugs that are most often used in reproductive technologies in fish breeding. The subject of the study was an ordinary pike perch (Sander lucioperca). The purpose of the study was to compare the effects of hormonal stimulants on the reproductive performance of female walleye during artificial reproduction. It was shown that in terms of the effectiveness of exposure, natural (carp pituitary gland) and synthetic stimulants (surfagon, gonaderil, ovopel) of gametogenesis had significant differences. Under the influence of a natural stimulator of oogenesis, the number of mature females from the number of injected ones was 50%. Testing of the preparations surfagon, gonaderil and ovopel showed that for hormonal stimulation of maturation of sexual products of female pike perch in dosages recommended by the manufacturers of the preparations, as well as calculated according to literary data, they are ineffective.

The results of comparative studies have shown that the most effective stimulant of maturation of zander sexual products is a preparation based on carp pituitary gland. Of the three synthetic drugs compared, none gave stable results.

The article presents the results of the study of the possibility of using protein substances obtained from the blood and organs of livestock to increase the resistance and adaptation of the Cyprinus carpio organism of different age groups.

This article presents the results of a dissertation research conducted from 2021 to 2023 on the topic: “Assessment of Environmental Factors’ Impact on Safety of Aquaculture Products (Live Fish) Produced by Fisheries Enterprises in Tashkent Region.” The study investigates how environmental factors affect pond fish species belonging to the carp family. It focuses on key ecological and zoohygienic aspects identified during monitoring activities at aquaculture farms and their influence on the life processes of carp fish. Overall, both enterprises provide conditions close to biological optimum for carp growth, although TCT FISH CLUSTER shows higher summer levels of ammonia, indicating the need for feeding optimization and increased water flow. Additionally, potentially hazardous benthic organisms have been detected that pose risks to commercial fish species raised in these aquaculture facilities.

The article is devoted to studying the current hydroecological condition of the Rezaksay reservoir and assessing its role in ensuring sustainable fisheries. Key hydrobiological and hydrochemical indicators characterizing water quality and ecosystem conditions are examined. The influence of natural factors and anthropogenic loads on fish population dynamics and ichthyofauna structure is analyzed. Special attention is given to problems related to feed base deficiencies and fish maintenance conditions, such as lack of natural food resources and possible episodes of oxygen deficiency. Prospects for developing fish farming in the region are evaluated based on existing limitations and potential opportunities for improving water quality and increasing aquatic productivity through environmentally safe technologies. The results obtained allow conclusions about prospects for expanding commercial fish production and recommendations for optimizing measures aimed at restoring and preserving populations of valuable fish species under current ecological circumstances.