The increase of immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii by feeding with selenium enriched-diet

The effects of inorganic selenium (Se) (sodium selenate, SSe) and organic selenium (seleno-l-methionine, MSe) supplementation on the immune response, antioxidant status, and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii, were studied. Five experimental diets, including a control diet (without Se enrichment), 0.5 mg (kg diet)−1 of MSe, 1 mg (kg diet)−1 of MSe, 0.5 mg (kg diet)−1 of SSe, and 1 mg (kg diet)−1 of SSe, were used. After 75 days of culture, prawn fed the Se-enriched diets had lower mortality compared to that of prawn fed the control diet after being challenged by the pathogen, Debaryomyces hansenii. No significant differences in the total hemocyte count, superoxide dismutase activity, or clearance efficiency of prawn were recorded among the control and treated groups. Significantly increased phenoloxidase and phagocytic activities in prawn fed the Se-enriched diets were found compared to the controls. Respiratory bursts of prawn fed both forms of 1 mg Se (kg diet)−1 significantly increased compared to control prawns. For the antioxidant status analysis, glutathione peroxidase, glutathione reductase, and glutathione s-transferase of prawn fed the SSe-enriched diet at 1 mg (kg diet)−1 were significantly increased. The results indicated that the cheaper selenium, SSe is recommended to be added in prawn feed at the concentration of 0.5 mg resulting in 1.5 mg SSe (kg diet)−1 increased prawn immunity and disease resistance against the pathogen, D. hansenii.