The use of probiotic Liquafid in capsule form in the cultivation of rainbow trout in a RAS

The article presents materials on the use of the probiotic “LikvaFid” in encapsulated form in juvenile rainbow trout when growing in a closed water supply (UZV) installation. The encapsulated form allows the strains to be delivered directly to the intestines of fish. The probiotic in encapsulated form was made using a capsulator manufactured by MZTA LLC. As a result of experimental work, a significant increase in body weight was observed, as well as an increase in survival in the experimental group. In UZV conditions, there is a danger of bacterial diseases. At the same time, it is desirable to minimize the use of antibiotics in order to avoid a negative impact on the biofilter microflora. In modern industrial fish farming, various probiotic and immunomodulatory drugs are actively used. Probiotic “LikvaFid”, containing live cultures of Bacillus megaterium and Bacillus subtilis bacteria (manufactured by BIOTROF LLC, St. Petersburg) as active substances, allows normalizing the intestinal microbiota. Experimental work on the use of the domestically produced probiotic “LikvaFid” was carried out at the fish breeding enterprise of the FSGCR branch of the Federal State Budgetary Institution “Glavrybvod” (Leningrad Region, Ropsha settlement). Rainbow trout aged one year old was chosen as the subject of research. The drug “LikvaFid” was administered in encapsulated form orally with food in one course, the duration of which was 35 days. Analysis of the results of experimental work showed an increase in growth rate in the experimental group. Research work confirms the beneficial effect of this drug in encapsulated form on the digestive processes of fish. Strains of Bacillus subtilis and Bacillus megaterium, due to their probiotic activity, have been found to promote the growth of normal intestinal microflora and suppress pathogenic and opportunistic microflora. Improved absorption of nutrients in the gastrointestinal tract and stimulation of the immune system promote more active growth of rainbow trout.