Abstract
Preservation of the nutritional value of fish and the useful qualities of its rich composition is extremely important. The urgent task of the food industry is to develop and create quality food products that meet modern production trends and compete in domestic and foreign markets. This scientific paper describes studies aimed at assessing the specific weight (%) of essential nutrients (glycogen, proteins, and lipids) in particular organs and tissues of different size and mass groups of the hybrid of silver and bighead carp experimental ponds and reservoirs of Ukraine. To achieve the goal in the research process, fish farming, biochemical (study of total protein, lipids, and carbohydrates), and statistical (mathematical processing of research results) research methods were used. In all size and mass groups of the hybrid of silver and bighead carp from ponds and reservoirs in 2017, 2018, and 2019, mostly satisfactory values of general metabolism indicators were found - glycogen, proteins, and lipids in the liver, gills, and muscles of fish. In annual fish of winter ponds, total protein and glycogen content in all organs and tissues was slightly reduced. The organisms of biennial fish from feeding ponds were characterized by fluctuations in the content of glycogen in the liver (it was the highest in fish, 3.28 – 3.33%). Significant fluctuations in the total protein content of muscle, liver, and gills and a slight excess of glycogen in the liver and lipids in the gills of three-year-olds were observed in the reservoirs. The difference found in the availability of essential nutrients in the body of the studied fish indicates a change in the intensity and direction of their metabolic processes. However, their physiological condition at the time of the study was within normal limits.