The form of supplemented Se defines its bioavailability and efficacy as antioxidant. Research in terrestrials shows that the bioavailability of hydroxy-selenomethionine (Selisseo) is similar to that of selenomethionine. However, if the two organic forms behave the same in aquatic species had not been corroborated to date.
A new peer-review publication at Aquaculture Nutrition (DOI: 10.1111/anu.13385) by the Aquaculture Research Group of the National Pingtung University of Science and Technology (Taiwan) shows new evidence on the bioavailability of hydroxy-selenomethionine and selenomethionine in low fish meal feeds fed to giant grouper. While both forms enhanced selenium retention and antioxidant capacity of low fish feeds, hydroxy-selenomethionine showed greater efficacy in terms of hepatic antioxidant activity, reduction of hepatic lipid peroxides, and whole body selenium retention. This study adds further evidence to the efficacy of pure and stable hydroxy-selenomethionine to build the antioxidant system and support fish in dealing with the negative impact of stress.