effects of different levels of sodium diformate and formic acid salt on growth performance, digestive enzymes, and innate immunological parameters of beluga (huso huso) juveniles

The purpose of this study is to evaluate the effects of sodium diformate (ndf) and formic acid salt on the growth performance, nutrition indices, innate immune system, and digestive enzymes activity of 420 huso huso (30.55 ±1.72 g) were randomly divided into seven experimental treatments. all groups were fed with the experimental diets for 60 days. the experimental diets contained 0.05%, 0.1% and 0.15% ndf and 0.05%, 0.1% and 0.15% formic acid. diet control was without any acidifier. results show that the best fcr and sgr were observed in the group fed with 0.1% supplemented food by ndf and formic acid (p<0.05) on the 30th and 60th day , respectively. the results show that the immunological parameters including total immunoglobulin (by 0.1% ndf), serum bactericidal activity (by 0.1 %ndf and 0.1 %formic acid), and lysozyme activity (by 0.05 and 0.1% ndf) were affected significantly by acidifier (p<0.05). the highest activity of trypsin and chymotrypsin was significant in groups 0.1 % supplemented food by ndf (p˂0.05) in the first 30 days. it can be concluded that the addition of 0.1% of ndf to beluga diets improves growth parameters decreases fcr, increases immunity levels and digestive enzymes activity.