Comparative analysis of the results of backcrossing during selection of carp

Abstract

A study of the fish-breeding and biological characteristics of two- and three-year-old hybrids of third-generation carp and reverse-crossing carp was carried out. As a result, a higher Fulton fatness coefficient was revealed in returncrossing carp, as well as their more effective plastic exchange, characterized by feed payment. The exterior indicators for the progonicity index of both two-yearolds and three-year-olds in return-crossing carp had lower values than in hybrids. Consequently, in this group of fish, as a result of the return crossing of carp hybrids with an improver breed (Moscow scaly), a more pronounced high-spin was observed. The additional calculation carried out for the variation of the studied index revealed slightly lower coefficient of variation in two- and three-year-old carp hybrids than in return-crossing carp, which can be explained by the effect of stabilizing selection during three generations of breeding. The use of such an important indicator as the mass accumulation coefficient made it possible to establish its higher values in two-year-old carp of return crossing. The consequence of such a high weight gain in this repair group of carp may be a significantly lower average weight in yearlings of return crossing when stocking outgrowth ponds (15.8 g versus 88.3 g in third-generation carp hybrids). The highest indicators for the accumulation mass coefficient were noted for both two-year-olds and three-year-olds of two groups of carp in the period from May to June, which corresponded to a more intensive development of the natural forage base in the growing ponds during this period of time.