Effect of Lactobacillus supplementation on growth and disease resistance in tilapia.

【Objective】The present experiment was conducted to observe the growth properties and disease resistance in tilapia fish on supplementation of Lactobacillus in their feed. 【Method】Different concentrations (0, 0.1, 0.2 and 0.3%) of Lactobacillus were added to the feed used for raising tilapia, the weight increment, survival rate and feed coefficient were calculated after 20 days. The fishes were artificially infected with Streptococcus iniae suspension derived from diseased tilapia, and the intestinal flora and accumulated mortality of tilapia were recorded after 2 and 7 days, respectively. 【Result】The results showed that the feed containing Lactobacillus decreased the feed coefficient significantly and resulted in a significant increase in the weight gaining rate, which increased with increase in Lactobacillus concentration in feed, however, the feed coefficient showed a decreasing trend. The disease resistance of tilapia fed with feed containing Lacto-bacillus was higher than that the control and enhanced with increasing Lactobacillus concentration in feed. The reproduction of intestinal flora in tilapia infected with S. iniae was found to be inhibited by Lactobacillus. 【Conclusion】Lactobacillus supplementation was found to improve the growth of tilapia and enhance the disease resistance, and could be recommended for commercial aquaculture production systems.