Use of probiotics Bacillus coagulans, Rhodopseudomonas palustris and Lactobacillus acidophilus as growth promoters in grass carp (Ctenopharyngodon idella) fingerlings

The present research evaluated the effects of three probiotics on the growth performance and intestinal digestive enzyme activity in fingerlings of grass carp, Ctenopharyngodon idella. Three treatments (T-1, T-2 and T-3) were fed with diets containing different viable bacteria with a final concentration 10(6) CFU g(-1) feed (Bacillus coagulans, Rhodopseudomonas palustris and Lactobacillus acidophilus, respectively) and the control was fed with basal diet without probiotics. All the diets supplemented with probiotics resulted in better (P < 0.05) final weight, daily weight gain and relative gain rate than control but no significant differences were observed among the treatment groups. The highest protease activity was observed in T-1. However, T-2 and T-3 showed no difference (P > 0.05) in protease and cellulase activities compared with the control. The protease activity was higher in the foreintestine than in the hindintestine (P < 0.05), and the reverse was observed in cellulase activity. As for amylase activity, there was no difference between foreintestine and hindintestine. In conclusion, the three selected probiotics increased the growth performance of grass carp fingerlings. Furthermore, different digestive enzyme activity was observed in different intestine segment.