Comparative effects of dietary inorganic and nano forms of selenium on growth, hematological, biochemical, and antioxidant responses in Nile tilapia (Oreochromis niloticus).

This study compared the effects of dietary inorganic sodium selenite (Na₂SeO₃) and green-synthesized selenium nanoparticles (SeNPs) on growth performance, hematological indices, serum biochemical parameters, and antioxidant status in Nile tilapia (Oreochromis niloticus). A total of 180 fish were randomly assigned to three dietary groups (control, Na₂SeO₃, and green-synthesized SeNPs) and fed the experimental diets for 90 days. Green-synthesized SeNPs were produced using Viscum album L. root extract. Compared with the control and Na₂SeO₃ groups, fish fed the SeNP-supplemented diet exhibited significantly higher (P < 0.05) final weight, weight gain, specific growth rate, red blood cell count (RBC), hemoglobin (Hb), hematocrit (Hct), total antioxidant status (TAS), catalase (CAT), and glutathione peroxidase (GPx) activities, together with a significantly lower feed conversion ratio (FCR). In addition, serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), glucose, triglycerides, cholesterol, and malondialdehyde (MDA) levels were significantly reduced (P < 0.05) in the SeNP group compared with the other treatments, indicating improved physiological status and reduced oxidative stress. These findings demonstrate that green-synthesized selenium nanoparticles are a more effective and environmentally sustainable selenium source than inorganic sodium selenite for enhancing growth performance, physiological health, and antioxidant capacity in Nile tilapia.