SYNERGETIC EFFECTS OF DIETARY PROBIOTICS WITH PREBIOTICS ON GROWTH PERFORMANCE OF JAPANESE EEL Anguilla japonica

A 12-week feeding trial was conducted to investigate the effects of dietary probiotics Bacillus subtilis and Bacillus licheniformis with prebiotics mannan oligosaccharide (MOS) or fructo oligosaccharide (FOS) on growth performance in Japanese eel, Anguilla japonica. Fish averaging 12.8±0.47g (mean±SD) were randomly divided into 5 treatments of three tanks (10 fish/tank) and fed one of the five experimental diets. A basal diet without supplementation was used as control diet (Con), and four other diets were formulated by adding probiotics (10⁸ CFU/g diet) with prebiotics (5 g/kg diet); B. subtilis and MOS (BSM), B. subtilis and FOS (BSF), B. licheniformis and MOS (BLM) and B. licheniformis and FOS (BLF). At the end of the experiment at period, weight gain, specific growth rate and hepatosomatic index of fish fed BSM and BSF diets were significantly (P˂0.05) higher than those of fish fed Con diet. Although, there were no significant differences (P>0.05) among fish fed BSM, BSF, BLM or BLF diets with no significant interactions (two-way ANOVA) of probiotics or prebiotics on growth performance. Therefore, these results indicated that dietary synbiotics consisting of B. subtilis with MOS (BSM) or FOS (BSF) could be more beneficial than other synbiotics (BLM, BLF) to the growth performance of Japanese eel.