Abstract:
The relevance of the study is conditioned by the defining role of the stage of early
development in the ontogenesis of young fish in the formation of their growth rate potential.
The physiological and biochemical status of the body determines the adaptive capabilities of
hydrobionts, so the use of biologically active substances when rearing fish was chosen as one of
the vectors for improving the development parameters. The purpose of the study was to determine
the effectiveness of introducing technological elements (supplementary feeding, rearing) in
the early stages of the ontogenesis of young fish. The study was based on theoretical (analysis,
synthesis, comparison, modelling), experimental, and laboratory methods adopted in fisheries,
physicochemical studies. A clinical examination of fish, monitoring of growth rates, weight gain,
survival rate, and physiological state was carried out.The average weight of fingerlings exceeded the parameters in the
control group for carp by 3.5% and for silver carp by 3.8%. The total number of red blood cells
in the silver carp experimental group was 7.4% higher than the control (p < 0.05), haemoglobin
content – by 4.7%, haematocrit – 9.9%. The total number of red blood cells in the blood of carp
in the experimental group was 4.9% higher, and the haemoglobin content was 3.1% higher than
in the control group. In the experimental group, the total protein content exceeded the value in
relation to the control group for silver carp by 15.9% (p < 0.05), and for carp – by 23.9% (p < 0.01).
Enzymatic activity in the experimental group was higher compared to the control group. The
proposed method of feeding helps increase the growth rate of fish. The practical value of the
study is to help improve qualitative and quantitative parameters, in particular, the biochemical
composition of the muscle part for carp and silver carp in samples in the experimental group in
comparison with control values
