Effect of beta-glucans on hematological, immunoglobulins and stress parameters of striped catfish (Pangasianodon hypophthalmus) fingerling
Can Tho University Journal of Science
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
... 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.