Effects of Diets Containing Inorganic and Organic Forms of Selenium on the Growth Performance and Antioxidant Status of the Giant Freshwater Prawn, Macrobrachium rosenbergii

Abstract

To investigate and compare the effects of inorganic and organic selenium (Se) supplementation on Se accumulation, the growth performance and antioxidant status of the giant freshwater prawn, Macrobrachium rosenbergii, were examined after feeding five experimental diets, including a control diet (without Se enrichment), 0.5 mg/kg of seleno-L-methionine (MSe), 1 mg/kg of MSe, 0.5 mg/kg of sodium selenate (SSe), and 1 mg/kg of SSe. The bioavailability of inorganic Se (SSe) for prawn was better than that of organic Se (MSe) as evidenced by Se bioaccumulation and antioxidative enzyme activities of the prawn. The growth-performance trial showed that a basal diet containing about 1 mg/kg of Se is sufficient for prawn, because no significant differences in the final mean weight, survival rate, or feed efficiency after feeding the control diet and four Se-enriched diets for 77 days were found. After 77 days of culture, prawn fed the Se-enriched diets had greater enzyme activities, including higher superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione s-transferase compared to those fed the control diet. Thus, supplementation of prawn with Se did not improve growth performance, but positively affected antioxidation and detoxification; 1 mg/kg of a cheaper SSe enrichment resulting in 2 mg/kg Se in the diet for prawn is recommended.