Abstract
A 35-day trial was set to explore the effects of different dietary zinc sources on growth, insulin-like growth factor I (IGF-I) mRNA expression, meat quality, immune response, antioxidant activity, and immunohistochemistry of nuclear factor kappa B (NF-κ7B) of broiler chickens. Ross 308 broiler chicks (n = 156) were randomly assigned into four experimental groups. The G1 received the basal control diet without zinc supplementation; the G2, G3, and G4 were supplemented with zinc oxide, zinc lysine, and nano zinc oxide, respectively, at a level of 40 mg Zn/kg diet. The data revealed that nano zinc oxide linearly improved the overall growth performance parameters. Nano zinc oxide linearly elevated (P < 0.001) mRNA expression of IGF-I followed by G3. The pH value of breast muscle in G4 shows a linearly decreasing value (P < 0.001). Also, the linearly highest expressible release volume percentage and lightness (L*) value with the lowest redness (a*) value (P < 0.05) were recorded in G4 and G3. A numerical increase in the total antibody titer was recorded on the 35th day in the G3 and G4. A numerical elevation in the superoxide dismutase (SOD) and a numerical reduction in the serum malondialdehyde (MDA) were recorded in the G4. The section of the liver from G4 revealed significantly very low expression of NF-κB staining. It is concluded that nano zinc oxide is considered the more trending zinc source. It had no negative effects on the health status and can be used in broiler diet premix.