The study aimed to investigate the effect of beta-glucans on hematological, immunoglobulins and stress parameters of striped catfish. The study included two experiments. In the first experiment, experimental fish (16.2±0.74 g) was fed for 30 days with feed containing different betaglucans concentrations (0, 0.5, 1.0, 1.5, 2 and 2.5 g/kg). Fish blood were collected after 0, 1, 3, 7, 14 and 30 days of feeding for analysis of hematological parameters, whereas glucose, cortisol concentration and

more »

... al immunoglobulins (Ig) were analyzed before initiating experiment and after 7, 14 and 30 days of feeding. In the second experiment, experimental fish (18.5±0.65 g) was fed beta-glucans (1.0 g/kg feed) for one, two and three weeks. After feeding beta-glucans with different periods, fish was crowded stressing at high density (3000 fish/m 3 ) for four hours then transferred into tanks (500 L) at lower density (60 fish/m 3 ) and blood samples were collected after 24, 48 and 72 hours for analysis of glucose, cortisol concentration and Ig. The result of experiment 1 showed that fish fed 1 g beta-glucan/kg feed had significantly higher red blood cells, white blood cells, hemoglobin, hematocrit and Ig compared to other treatments. Blood glucose and cortisol concentration in treatment fed 1.0 g/kg feed were significantly lower compared to other treatments. In the second experiment, the concentration of glucose and cortisol in fish fed betaglucans (1g/kg feed) for three weeks were significantly lower compared to fish fed beta-glucans for one and two weeks when fish being stressed at high density. In fish fed beta-glucans for three weeks, total immunoglobulins was significantly higher than those of other treatments. In conclusion, the optimal level of beta-glucans adding into diet of striped catfish fingerlings should be 1.0 g/kg which improved fish health and stress resistance.