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 (P<0.05) 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 (P<0.05). 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 (P<0.05). Fish that received diet supplemented with Se-NP, Zn-NP, and Se/Zn-NP significantly (P<0.05) increased superoxide dismutase and catalase while reduced malonaldehyde activity compared to CG. Intestinal morphometry revealed significantly (P<0.05) 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.