the hematological improvement of rainbow trout (oncorhynchus mykiss) during dietary supplementation with vitamin c after exposure to zinc nano-particles

the aim of this study was to examine the adverse effects of zinc nanoparticles on hematological indices of trout and investigate the improvement of these indices after vitamin c treatments. this study assesses the protective role of vitamin c in fish exposed to zno nps. two concentrations of zno-nps (40 and 80 mg l-1) and two doses of vitamin c (400 and 800 mg per kg of feed) were used to treat 162 specimens of oncorhynchus mykiss. no mortality was observed during the test. after 5 and 10 days of exposure, hematological data were analyzed according to routine clinical methods. statistical analysis showed significant changes in wbcs and rbc on day 10 (p<0.05). values for ht and mch were significantly higher in treatment 2 (normal diet+40 mg l-1 zno-nps) and 9 (800 mg/kg vit + 80 mg l-1 zno-nps), and lower in treatment 3 (normal diet+80 mg l-1 zno-nps) in comparison with the control group (normal diet+0 mg l-1 zno-nps) (p<0.05). no significant differences of mcv and mchc were observed (p>0.05), while significant increase in neutrophils and monocytes, and decrease in lymphocyte cells were recorded (p<0.05). zno-nps stimulated the immune system of o. mykiss, but this effect did not have any lethality on this species at 40 and 80 mg l-1. vitamin c in different concentrations could help to prevent rainbow trout from the toxic effects of this nano metal.