The effect of the beet molasses on the growth rate and resistance of carp fingerlings (C. carpio L.) exposed to a single sublethal exposure to copper sulfate

The effect of the addition of beet molasses to fish feed on lipid peroxidation, fish-breeding, biological and morphological parameters of carp fingerlings (C. carpio L.) under control conditions and subjected to a single sublethal exposure to copper sulfate was studied. The fish were fed daily, at the rate of 2% of the body weight feed. Copper sulfate treatment was carried out once at the rate of 3 ml of 10% solution per 20 liters of water, for 24 hours. The duration of the experiment was 30 days. Growth parameters and survival were determined in all fish with an interval of 2 weeks. The intensity of lipid peroxidation was determined in the gills by the content of malonic dialdehyde. The liver was taken for histological analysis. The best fish-breeding and biological indicators were found in control individuals and experimental feed variants with the addition of beet molasses, including under the influence of copper sulfate. All feed options led to an increase in the intensity of lipid peroxidation processes in the gills. Beet molasses showed an antioxidant effect only under conditions of increased oxidative processes caused by copper sulfate. There was a decrease in the content of malonic dialdehyde in the gills by 12%, but the intensity of lipid peroxidation still remained 34% higher compared with the control. During the studied period, no morphological changes were detected in the liver.