Scientific Reports of the National University of Life and Environmental Sciences of Ukraine

The article considers the issue of efficiency of use of complete feed with different level of metabolic energy for growing rainbow trout this year. The purpose of the experiment was to establish the influence of different levels of energy supply of trout on its productivity. For this purpose, five experimental groups were formed by the method of analogues. During the equalization period, the experimental fish consumed feed of the control group. In the main period, the level of metabolic energy in trout feed ranged from 15 to 19 MJ per 1 kg. As a result of research, it was found that the use of trout feed with high energy nutrition (19 MJ) in the feeding of this year is accompanied by an increase in their weight by 10.4 % (p<0.05) and growth intensity - by 5.9-13.2 % , compared with analogues that consumed feed with a nutritional value of 17 MJ. Reduction of this indicator to 15 MJ/kg contributes to a probable decrease (p<0.05) in weight by 10.7 %, and a decrease in growth intensity by 5.3-12.7 %. It is proved that the cost of feed per 1 kg of weight gain in this year's trout, which received feed with an energy content of 19 MJ was lower by 3.9 %, and with its content of 15 MJ - 6.7 % higher compared to fish, which consumed feed with an energy content of 17 MJ/kg. The safety of experimental fish throughout the experiment was at a high level of 74.3-76.7 %. However, it was found that the most economically feasible is the cultivation of trout this year, which consume feed with a nutritional value of 17 MJ of metabolic energy, compared with a decrease or increase of this indicator to 15 or 19 MJ, respectively

rainbow trout, fish feeding, mixed feeds, metabolic energy, productivity, economic efficiency