The effect of biologically active feed additives in the diet on the hematological parameters of fish

Hematological analysis is one of the main tools for assessing the effect of various feed additives on the animal body. The article presents the results of the effect of biologically active feed additives on the growth and morpho-biochemical parameters of the blood of carp (Cyprinus carpio). For 42 days, in addition to the basic diet, vanillin (I experimental), probiotic (II experimental), vanillin + probiotic complex (III experimental), vanillin + ultrafine particles of silicon dioxide + probiotic (IV experimental) or vanillin + ultrafine particles of silicon dioxide + Zn + I + Cr + Co complex (V experimental), were included in the yearlings' diet. It was found that feed additives had a different effect on the body of fish. If in the I, II and V experimental groups an increase in live weight was recorded to 10.2% (P≤0.01), then in the III and IV experimental groups the growth of fish decreased relative to the control to 19.6% (P≤0.001). Morphological blood analysis showed that biologically active feed additives contributed to an increase (P≤0.05) in hemoglobin in all experimental groups, with the exception of groups III and V, where a decrease (P≤0.05) was recorded. In the study of biochemical parameters, a general trend of changes in a number of indicators was recorded in groups whose diet included probiotics. There were significant differences in the concentration of ALT, total protein, triglycerides and cholesterol. Thus, the effect of biologically active feed additives contributed to obtaining distinctive results. Positive results on hematological parameters were established in the I and V experimental groups, while ambiguous results were found in the II, III and IV groups.