Synergistic Effects of Selenium Nanoparticles and Vitamin E on Growth, Immune-Related Gene Expression, and Regulation of Antioxidant Status of Nile Tilapia (Oreochromis niloticus).

The present study was conducted to investigate the effects of nano-selenium (Nano Se) or/and vitamin E (VE) on growth performance, blood health, intestinal histomorphology, oxidative status, and immune-related gene expression of Nile tilapia. Nano Se or/and VE at a rate of 0, 1 mg Nano Se/kg, 100 mg VE/kg, and 1 mg Nano Se/kg + 100 mg VE diet were fed to fish for 8 weeks. FBW was significantly (P < 0.05) increased in fish fed with Nano Se and VE, while fish fed with Nano Se or Nano Se and VE diets displayed significantly (P < 0.05) higher WG and SGR than the other groups. The lowest FCR was significantly (P < 0.05) detected in fish fed with Nano Se and VE, while the highest value was observed in fish VE diet. The intestinal morphometry (villi length and width) of fish fed with Nano Se or/and VE reported significantly (P < 0.05) the highest values with high number of goblet cells. Blood hematology and biochemistry parameters of fish fed with Nano Se or/and VE showed normal values with insignificant differences except for the blood total protein increased in fish fed with Nano Se or/and VE (P < 0.05). Dietary Nano Se or Nano Se and VE significantly (P < 0.05) increased the GPX, SOD, CAT, NBT, lysozyme, and phagocytosis values with decreased MDA. Liver and spleen TNF-α and IL-1ß expressions were significantly (P < 0.05) upregulated in fish fed on Nano Se or Nano Se and VE. Thus, Nano Se or/and VE can be used effectively in tilapia diets for improving the growth, intestinal health, blood health, oxidative status, and immune-related gene expression.

The potential role of nano-selenium and vitamin C on the performances of Nile tilapia (Oreochromis niloticus).

Functional trace elements and vitamins can boost immunity and antioxidative response in aquatic animals without creating environmental hazards. While nano-selenium (Nano-Se) and vitamin C (VC) have been used as immunomodulators and antioxidants in animal and poultry feed, there is little data on Nano-Se and/or VC supplementation in aquatic animals. Thus, the current study evaluated the impact of adding Nano-Se and VC to the diets of Nile tilapia for 8 weeks. Four diets were formulated and offered to the fish: no supplementation (control), 1 mg Nano-Se/kg, 500 mg VC/kg, and 1 mg Nano-Se + 500 mg VC/kg of food. Growth-related parameters (final body weight, weight gain, and specific growth rate) were significantly increased in tilapia fed Nano-Se and VC, with a reduced feed conversion ratio (P < 0.05). Intestinal villus length and width as well as the number of goblet cells were increased in tilapia fed Nano-Se and/or VC (P < 0.05). Additionally, dietary Nano-Se and/or VC significantly increased nitro-blue tetrazolium (NBT) level, superoxide dismutase, glutathione peroxidase, catalase, the phagocytic index, and lysozyme and phagocytic activities (P < 0.05). However, significantly reduced levels of malonaldehyde were observed in fish fed Nano-Se and/or VC (P < 0.05). TNF-α and IL-1ß gene expressions in the liver and spleen of the fish were significantly upregulated by Nano-Se and/or VC (P < 0.05). The results revealed the potential role of Nano-Se and/or VC in enhancing growth, intestinal morphometry, and immune and antioxidative responses in Nile tilapia.