Effect of administration Bacillus probiotic individual or with sodium di-format on intestinal morphology in Salmo trutta caspius

This study was aimed to evaluate the single and combined effects of sodium diformate as an acidifier and bacilli probiotics (Bacillus subtilis and B. licheniformis) on intestinal histomorphology of juvenile Salmo trutta caspius or 60 days. Hundred juvenile fish weighing 12. 6±1. 4 g were divided into 4 different treatments, including control, 0. 4g B. subtilis+ B. licheniformis /kg diet, 0. 5g sodium diformate/kg diet and their combination (0. 4g B. subtilis+ B. licheniformis + 0. 5g acidifier sodium diformate/kg diet). Blood and intestine samples (9 fish/ treatment) were withdrawn at two different time intervals, i. e., days 30 and 60. The results showed that the microvilli height, parin lyer and the thickness of epithelium was reduced (P>0. 05) at day 30 as a result of single acidifier while the combined treatments led to either significant increase (P<0. 05) or no change as compared with corresponding single treatments and control group. Our data suggest that bacilli probiotic applied here was much successful to improve fish health status and growth performance rather than sodium diformate.