In recent years, the world demand for a low fat and high protein content lean meat had increased to meet the needs of the organism in proteins. This article presents the results of an expedient scientific-research analysis on establishing the influence of Poll Dorset and Texel breed on the particular growth variability, development of both meat and wool productivity of Kazakh mutton-semifine-wool breed of sheep. Results of the study were obtained under the same grazing conditions of 110 head of purebred and 110 crossbreed Texel and Poll-Dorset sheep of second generation. It was found that peers of the experimental group exceeded their peers in the control group on the dynamics of growth in body weight (P£0.05), i.e. crossing helped to improve the performance of daily gain (P£0.05). In terms of slaughter indicators, such as the slaughter and carcass weight, crossbreed male lambs also surpassed purebred male lambs (P£0.05). Herein, it was found that crossbreed lambs of Texel breed observe the superiority in terms of meat output (fat free) in relation to purebred male lambs (P£0.01). The study of longissimus muscle chemical composition showed that crossbreed male lambs of Texel breed in protein content in this very muscle are superior to purebred peers (P£0.05). A study of wool characteristics of experimental sheep showed that at the age of 12 months the high wool clip was observed in male lambs of Texel second generation (P£0.05). The high yield of washed wool was also observed in Texel male lambs (P£0.05) as compared to purebred peers.

The effect of water mineralization on zooplankton productivity in the reservoirs of the Akmola region is a very relevant study. The chemical composition of natural waters is inextricably linked to the composition and structure of the soil, which, in turn, was formed during the long evolution of the earth's crust under the influence of climate. Natural waters have a wide variety of qualitative and quantitative chemical composition. The basis for systematization in existing classifications are the amount of mineralization, the predominant component or group, the relationship between different values of concentrations of various ions, the presence of increased amounts of any specific elements of the gas and salt regimes. The relevance of the work is due to insufficient study of the fishing potential of medium-sized reservoirs in Northern Kazakhstan. The work aimed to study the mineralization of water as a factor determining the life of aquatic organisms. As a result of this research, data confirmed the position that the factors that determine the viability of marine organisms are the mineralization of water. To characterize zooplankton across the entire lake area, samples were taken, taking into account different stations. The number of individual organisms in the sample was determined. The degree of mineralization of lakes in the Akmola region was indicated. The correlation coefficient for features in the "mineralization – zooplankton abundance" pair was calculated as r = -0.96, and in the "mineralization – zooplankton biomass" pair r = -0.85. When analyzing the data obtained, it was observed an inverse relationship between water mineralization and zooplankton abundance. When water mineralization increases by 4.03% in July, the number of zooplankton organisms decreases from 170.03 to 152.6 thousand copies/m3. When the salinity of the Uyali - Shalkar lake water increases from 362 (May) to 508 mg/L (July), the zooplankton biomass decreases from 6.02 to 5.73 mg/m3.

Over recent years much attention has been paid to the fishery use of geothermal sources. The prospects for this area are enormous, as it opens up possibilities for managing fish-breeding processes, regardless of climatic conditions. The main objective of the research was a comprehensive study of the technological processes of growing. One of the promising reserves for increasing fish production is the rational fishery use of waste warm water and geothermal sources. Research work was carried out in 2019 based on the farm of “Tengri Fish” LLP, which is located 270 kilometers from Almaty. The collection and processing of materials were carried out according to generally accepted methods in ichthyology and fish farming, followed by their analysis on a PC. Based on the results of the research, technological primaries of growing tilapia in a RAS (Recirculating Aquaculture System) using geothermal waters were determined. During the research, work was carried out to optimize the hydrochemical regime. The main fish breeding and biological indicators for the growth and development of tilapia were established. The optimal stocking density of tilapias in recirculating aquaculture systems using geothermal waters and the temperature when tilapias have a higher average daily weight gain were found. The novelty of the research: a complex study of biology and adaptation of a new object of industrial fish farming of tilapia and clarium catfish has been carried out outside the range and determined the adaptation possibilities of tilapia and clarium catfish to extreme factors of the aquatic environment.