Use of Garcinia sp. seed extracts as dietary supplement to promote growth and control fish diseases

Vaccines and antibiotics are commonly used to control or prevent outbreaks of diseases in farm animals, including cultured fishes. However, besides being expensive, the widespread use of antibiotics has led to the appearance of drug-resistant bacteria. Garcinia sp., a tropical plant with demonstrated antimicrobial properties against human pathogens and physiological effects in mice, is potentially useful in aquaculture for controlling fish pathogens, enhancing immunity and promoting fish growth. There are no previous studies that examined whether extracts from the plant can inhibit fish pathogens. This project investigates the feasibility of using Garcinia sp. as a dietary supplement to promote rainbow trout (Onchorynchus mykiss) growth and control fish diseases. To determine effects on growth, fish were fed to satiation diets containing extracts from the seeds at concentrations ranging from 0 to 20 g/kg. Additionally, the inhibitory effects of the extract on selected fish and shellfish pathogens are being assessed using the disk diffusion method. Results will be presented and significance discussed in relation to fish production and disease control in the aquaculture industry.