A survey on growth indices and intestinal enzymes in activity affected by feeding Beluga juveniles (Huso huso) subjected towith a diet containing different levels of dietary -sodium chloride (NaCl)

The current study carried out to investigate the effects of adding salt (NaCl) in the diet of beluga, Huso huso and its impacts both on the function of intestinal enzymes and growth indices and food efficiency. In this regard, 480 species of Huso huso with a mean weight of 173.8 ± 0.49 g stocked in 12 fiberglasses 2000-liter tanks for 12 weeks. They fed a diet containing different levels of NaCl including 0, 3, 6 and 9 percent. Growth indices including final weight, SGR and daily growth showed significant differences in fishes of all treatments, except the fishes fed the diet containing comparing control group (p < 0.05) Weight gain percentage of fed fish at 6% sodium chloride level was significantly higher than fish fed control but no statistically significant difference was observed between other treatments. The mean FCR in fishes of control group was significantly higher than other treatments (p < 0.05). The mean rates ofrate of intestinal enzymes including Alkaline phosphatase, protease, lipase and amylase in the fishes fed by different levels of NaCl were significantly more than control group (p < 0.05). It is suggested to achieve a higher growth rate, improve food efficiency, reduction of production costs and enhancement of intestinal enzymes function. appropriate percentage of added NaCl is to be 3-6% per kilogram of diet for farmed beluga of at 150 to 700 g.