Synergistic Effects of Selenium and Zinc Oxide Nanoparticles on Growth Performance, Hemato-biochemical Profile, Immune and Oxidative Stress Responses, and Intestinal Morphometry of Nile Tilapia (Oreochromis niloticus)

This study was aimed to investigate the synergistic effects of selenium (Se-NP) and zinc oxide (ZnO-NP) nanoparticles on growth performance, hemato-biochemical profile, immune and oxidative stress responses, and intestinal morphometry of Nile tilapia (Oreochromis niloticus). Monosex Nile tilapia (12.50 ± 1.03 g, N= 180) were randomly allocated into 4 groups in triplicates. Fish were fed diet supplemented with 0 Se-NP and Zn-NP (control group, CG), while fish in the other experimental groups were fed diet supplemented with 1 mg/kg diet Se-NP (Se-NP group), 10 mg/kg diet ZnO-NP (Zn-NP group), and a mixture of 1 and 10 mg/kg diet Se-NP and Zn-NP, respectively (Se/Zn-NP group) for 60 days. Fish fed diet containing Se-NP, Zn-NP, and Se/Zn-NP showed higher final body weight, weight gain, weight gain rate, specific growth rate, and lower feed conversion ratio with respect to CG (P0.05) with the highest being in fish fed with Se/Zn-NP. Fish fed with Se/Zn-NP showed higher hemoglobin, red blood cells, and globulin (P0.05). The highest phagocytic activity, phagocytic index, lysozyme activity, and immunoglobulin M was recorded in fish that received Se/Zn-NP followed by Se-NP, Zn-NP, and the lowest in CG (P0.05). Fish that received diet supplemented with Se-NP, Zn-NP, and Se/Zn-NP significantly (P0.05) increased superoxide dismutase and catalase while reduced malonaldehyde activity compared to CG. Intestinal morphometry revealed significantly (P0.05) increased villi length and goblet cells number in fish fed with Se-NP and/or Zn-NP. In conclusion, dietary supplementation of Nile tilapia with Se-NP and Zn-NP induces synergistic effects that improve growth performance, blood health, and intestinal histomorphology.