Analysis of indicators of lysozyme activity of blood serum of rainbow trout (Oncorhynchus mykiss) when using the drug "Smartbiotic"

Abstract

In this study, to activate the humoral link of nonspecific resistance of the fish organism, as well as to stimulate growth and development, prevent infectious and invasive diseases, the drug "SmartBiotic" was used, which contains humic acids. The research was carried out on the basis of LLC "Lososevo - whitefish nursery" Kingisepsky district, Leningrad region, the village of Velkota, which is the largest nursery in the city of Kingisepp for breeding rainbow trout. For the study, three groups of underyearlings of the rainbow trout (Oncorhynchus mykiss) were formed. One group served as control, and the other two were experimental. The first experimental group of young of the year received the drug at a concentration of 0.15%, and the second experimental group - at a dose of 0.25%. In the control group of rainbow trout, SmartBiotic was not used. All three groups were formed using the analog pairing method and raised in three different pools. Blood serum samples were taken twice: before giving postbiotic and one and a half months after using the drug. In the blood serum of fish in all three groups, the lysozyme activity of blood serum was determined according to the generally accepted method.