Comparative Study of Different Levels of Sodium Di-formate (NDF) and Formic Acidifiers on Nutrition, Growth and Activity of Digestive Enzymes in beluga (Huso huso)

Recently, the use of Acidifier (a group of organic acids) has been increased in aquaculture. The purpose of this study is to evaluate the effects of Acidifier (sodium diformate and Formic acid) on the growth performance, nutrition indices, and Digestive enzymes activity of the juvenile Huso huso. A total of 420 juvenile Huso huso (30.55 ± 1.72 g) was randomly divided into seven experimental treatments (Three replicates each). All groups were fed with the experimental diet for 60 days. The Bioassay conducted on the first day and after 30 and 60 days and then growth parameters were investigated. The experimental diets contain 0.05, 0.1 and 0.15 % sodium diformate (NDF) and 0.05, 0.1 and 0.15 % Formic acid (Formi). diet control was without any acidifier. Results show that all growth and Intestinal enzymes (trypsin, chymotrypsin and alkaline phosphatase) are affected by acidifier and in these two parameters  groups that fed 0.1 % supplemented food by NDF and citric acid compared to the control group. The best FCR and SGR observed in the groups fed with 0.1 % supplemented food by NDF)0.5±00), (0.5±0.005) (p < 0.05) at day 30 respectively. Although the best FCR and SGR observed in the groups fed with 0.1 % supplemented food by Formic acid (0.81±0.001), (2.7±0.005) (p < 0.05) at day 60 respectively. Intestinal enzymes (trypsin, chymotrypsin and alkaline phosphatase) are affected by acidifier. 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. Alkaline phosphatase activity increased with increasing acidifier diets in groups, but this increase was not significant compared to the control (p>0.05). It can be concluded that the addition of  0.1% of NDF to beluga diets improves growth parameters and decreases FCR, increases digestive enzyme activity. Moreover, these results indicated that 0.1 % of NDF and citric acid in the diet could be a useful food supplement preferably at 30 days and can be used to improve the growth parameters in juvenile Huso huso.