The study was conducted to assess nano zinc (ZnN) as a feed supplement with an aim to compare the supplemental dose of inorganic zinc (ZnI). ZnN was synthesized from 0.45 molar (M) zinc nitrate [Zn(NO3)2.6H2O] and 0.9 M sodium hydroxide (NaOH) and was confirmed to be of ZnN by TEM-EDAX measurements. Wister albino rats (rats; 84, 53.6 ± 0.65 g) were divided into seven groups (4 replicate with 3 rats each) and given feed supplemented with zinc for 60 days with either of the following diets: (1) normal control (NC): basal diet (BD) + no supplemental Zn; (2) ZnI-25: BD + 25 mg/kg Zn from inorganic ZnO; (3) ZnN-25: BD + 25 mg/kg of ZnN; (4) ZnN-12.5: BD + 12.5 mg/kg of ZnN; (5) ZnN-6.25: BD + 6.25 mg/kg of ZnN; (6) ZnN-3.125: BD + 3.125 mg/kg of ZnN; (7) ZnN-50: BD + 50 mg/kg of ZnN. T3 and insulin-like growth factor-1 (IGF-1) hormone levels were similar among groups (P > 0.05), whereas T4 and testosterone were significantly affected, based on supplemented dose. Zn supplementation improved both cell-mediated and humoral immunity. However, both cell-mediated immunity at 24 h and humoral immunity were statistically similar in ZnI-25 and ZnN-6.25 groups. Superoxide dismutase 1 gene expression was found to be similar in all experimental groups. The vascular degeneration were found in liver tissues moderately in NC, mildly in ZnN-6.25 and ZnN-3.125 groups, and no observable changes were noticed in kidney and spleen tissues. However, there was a mild damage in intestinal epithelium of ZnN-25 group rats, hyperplasia of goblet cells, and moderate damage in intestinal villi were observed in ZnN-50 group rats. From the study, it can be concluded that ZnN at half the dose of ZnI showed similar or better responses in terms of immunity, SOD-1 expression, hormonal profiles, and the tissue architecture of vital organs in rats, i.e., 25 mg/kg of Zn from ZnI and 12.5 mg/kg of ZnN impacted similar biological responses like immunity, SOD-1 expression, hormonal profiles, and the tissue architecture of vital organs in rats.
Keywords: Immunity status; Nano Zn; Organ architecture; Rats; Superoxide dismutase-1 (SOD1) gene expression.
© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.