COMPARATIVE CHARACTERISTICS OF THE BIOCHEMICAL COMPOSITION OF THE BODY OF UNDERYEARLINGS AND YEARLINGS OF CARP OF DIFFERENT BREEDS FROM THE BELARUSIAN COLLECTION
Studies of the biochemical body composition were carried out in underyearlings and yearlings of the fifth generation, adapted to the conditions of the second fish breeding zone of imported carp breeds of foreign selection, lines of Belarusian selection (tenth generation), grown simultaneously in ponds with similar hydrochemical conditions with the same feeding regime and sanitary and preventive measures. As a result of the study, a tendency to an increase in the content of dry matter (22.89 versus 21.81 %), fat (5.24 versus 4.48 %) and protein (15.18 versus 14.88 %) in collection lines of carp of Belarusian selection was established (Isobelinsky) in comparison with foreign breeds (German and Sarboyansky), grown simultaneously in the same conditions. In yearlings of collection lines of Belarusian selection, there is also a tendency to an increase in the content of dry matter (22.46 versus 18.66 %), fat (3.54 versus 2.68 %) and protein (14.89 versus 13.34 %), a decrease in moisture content (77.54 versus 81.64%) compared with overwintered collection breeds of foreign selection. In all collection groups of carp of Belarusian and foreign selection, after wintering, a decrease in the content of dry matter, fat, protein and an increase in the content of moisture and mineral substances in the body of yearlings was observed in comparison with underyearlings. As a result of the study of changes in indicators characterizing the biochemical composition of the body that occurred during the winter period, it was found that the deviations of biochemical indicators, especially the content of dry matter and fat, in breeds of foreign selection are significantly higher than in isobelinsky carp lines (Belarusian selection). The established deviations in most of the comparisons are statistically significant. Of all the breed groups considered, the most winter-hardy was the Isobelinsky carp cut “three prim”, in which the consumption of nutrients during the wintering was lower than that of the other experimental repair groups.