THE IMPACT OF PRODUCTION TREATMENTS OF FEED CONCENTRATE PRODUCED FROM WASTE OF CEREAL PRODUCTION ON ITS BIOLOGICAL VALUE AND EFFICIENCY IN THE COMPOSITION OF COMPOUND FEED FOR CARP
Authors: Koshak J. , Zenovich N. , Rybkina E. 
Published: December 2021

The following article presents a new raw component in compound feed for carp – feed concentrate produced from cereal production waste. The feed concentrate is based on several types of cereal fodder meal - wheat, pea, barley, as well as wheat bran and unshelled oat grain. The feed concentrate is balanced according to the needs of carp and can be used as feed for carp instead of wheat grain or as a part of compound feed for carp. Heat-moisture processing of compound feed before extrusion is one of the main stages that further ensure the stability of technological processes and the final quality of the feed concentrate. The amino acid composition was determined at various temperatures of the feed concentrate after heat-moisture treatment of + 40, 60, 70 and 80º С at a constant moisture content of the concentrate of +282° С. Amino acid score has been calculated for feed concentrates that have been exposed to various heat treatments. The amino score was calculated in relation to the carp's need for essential amino acids. It was found that an increase in the temperature of the concentrate during heat-moisture treatment leads to a decrease in the content of essential amino acids. For example, the total content of methionine and cysteine in the composition of the feed concentrate at a temperature of +75° C was 0.46%, with the minimum allowable total content of these amino acids in the composition of feed 0,5%. Heat-moisture treatment at a product temperature above +75° C leads to a decrease in the content of essential amino acids and the biological value of the feed concentrate.The process of extrusion of feed concentrate from waste of cereal production has been studied. The glucose content in the feed concentrate was studied at various extrusion modes. The glucose content indicates the degree of modification of the starch during the extrusion process, and the more glucose the product contains, the better it is absorbed by the carp. When extruded with an increase in temperature, the starch passes into a viscous-flowing (gelatinized) state, forming a so-called melt, the cooling of which also leads to the formation of a three-dimensional gel network. The feed concentrate granule becomes monolithic in structure; it becomes quite hard and can harm the intestines of carp. Therefore, it contains wheat bran in an amount of 1%, as a component that is able to weaken the feed concentrate granule. The degree of starch destruction in the composition of the extruded feed concentrate with the addition of wheat bran reached its maximum and the granule became porous, its hardness decreased. It was detected that when the temperature of the feed concentrate after extrusion rises above +100°C, the biological value of the feed concentrate decreases, and it becomes unbalanced in the content of such essential amino acids as lysine, threonine, methionine and cysteine. Therefore, the optimum product temperature after extrusion is +90-100˚C.The effectiveness of extruded feed concentrate was determined in the composition of granulated feed for two- and threeyear-old carp. The feed ratio of the compound feed containing the feed concentrate was 0.9 units, which is 64% lower than of the control compound feed, which includes a non-extruded grain group that is not balanced in terms of carp needs.