Determination of the efficiency of the use of amaranth (Amaranthus) in feeding of carp under different rearing conditions

Purpose. Determination of the effect of adding an Amaranthus (Amaranthus) supplement with anti-oxidant properties to the basic diet of carp on some fish-physiological parameters depending on rearing conditions. Methodology. Aquaculture, ichthyological and hydrochemical studies were conducted according to generally accepted methods in fish culture. The hemoglobin content in carp blood was determined by hemoglobin-cyanide method. The number of red blood cells in the blood of carp was counted in the Goryaev's chamber. Determination of protein content was carried out using the Bradford's method. The concentration of diene conjugates was estimated by a method based on the reaction of the optical density of the heptaninopropanol lipid extract. Determination of the concentration of TBK-active products was carried out spectrophotometrically by color reaction with thiobarbituric acid. The activity of superoxide dismutase (SOD) was determined by the inhibition of the reaction of nitrosin tetrazolium reduction in the presence of phenazine methisulphate. The activity of catalase was evaluated based on changing H2O2 concentration. Findings. The study analyzed the effect of feeding carp with grains of Ukrainian high-yielding feed grade amaranth with healing properties (Kharkiv-1) on physiological and biochemical parameters of fish organism. A comparative description of the efficiency of using this feed supplement under standard conditions of cultivation and the effect of a stress factor (water pollution as a result of intensification measures) was carried out. In both experiments, an increase in the number of formed blood elements was observed in the blood of experimental groups of fish: there was a tendency of an increase in the number of erythrocytes by 15-18.1% compared to control. Under optimum conditions of rearing, there was a tendency for an increase in body fat in the experimental group carp carps, while the effect of stress factors increases the protein (p<0.01) and fat contents compared to control. Under optimal conditions of cultivation, the tendency of an increase in SOD activity, both in muscles and in hepatopancreas of carp (by 5.9-8.3%.) was observed. Under the effect of stress factors, the activity of this enzyme was significantly increased (p˂0.01 ) that indicated on the activation of the anti-oxidant properties of amaranth in the event of negative factors. Originality. For the first time the effect of biologically active properties of amaranth on some fish and physiological parameters of age-1+ fish was studied and the effectiveness of its use under optimum conditions of cultivation, as well as the effect of stress factor was determined. Practical value. Laboratory simulation of high content of nitrites in water, as widely common stress-factor in fish farming, and comparison of its effect on some fish-physiological parameters of carp organism is justified and topical. Taking into account positive results of the introduction of this feed additive into the diet of carp, it is possible to solve the problems of fish farms caused by the intensification of production, namely: reduction in fish growth gain and their death due to hypoxia and the development of concomitant diseases as a result of organic pollution of the aquatic environment.