Broiler welfare is preserved by long-term low-dose oral exposure to zinc oxide nanoparticles: preliminary study.

The potential public health risk through utilizing of zinc oxide nanoparticles (ZnO NPs) in food constitutes the major obstacle to the expansion of nanoparticle (NP) in food industry. Liver histology, bone marrow and liver genotoxicity, immunity, and oxidant status were investigated upon long-term ZnO NPs feed supplementation. One hundred and sixty male IR (Indian River) chicks were randomly allocated to one of the four dietary treatments: control, ZnO NPs at 10, 20, or 40 mg/kg for 42 days. This study revealed non-significant hepatic histopathological alterations and DNA damage and the treatment had no influence on body and organ weights, liver enzymes, lipid peroxidation (MDA), IgG, IgM, and interferon gamma (IFN-γ). This study suggests that low-dose (< 40 mg/kg diet) long-term ZnO NPs supplementation to broiler chicks has no observed potential adverse effects on normal histology of the liver, blood physiology, immune system, and DNA damage of liver and bone marrows, which are critical features for validating ZnO NPs for use in food. Further studies are required to evaluate the probable withdrawal period of ZnO NPs before approval as a dietary supplement in broiler or livestock diets.

Zinc oxide nanoparticles prevent multidrug resistant Staphylococcus-induced footpad dermatitis in broilers.

The current experiment was designed to evaluate the effects of dietary supplementations of zinc oxide nanoparticles (ZONPs) on some behavioural, performance, welfare and histopathological changes in broilers exposed to multidrug resistant Staphylococcus aureus (MRSA)-induced footpad dermatitis (FPD). Eighty-four male Indian River (IR) broilers were randomly allotted to six different dietary treatments as follows: C-ve, C+ve, 10, 20, 30 and 40 ppm ZONPs from 7 to 49d of age. At day 28, broilers (n = 70) were sub-cutaneously injected with 0.5 ml of saline containing 5.3 × 107 CFU/ml of S. aureus (MRSA) in each metatarsal foot pad. Control (non-infected) broilers were given 0.5 ml of saline (n = 14). Results clarified that non-infected birds and ZONPs-fed birds had significantly higher standing and feeding activities and lower resting activities in comparison with the infected group. Also, the S. aureus infected group had significantly lower body weight gain (BWG) and higher feed conversion ratio (FCR) than the non-infected group. In addition, the non-infected birds and ZONPs groups had significantly lower object crossing and tonic immobility times (TI) and gait scores (GS) in comparison with the S. aureus group. Only ZONPs 30, 40 ppm and non-infected groups had a significantly higher latency to lie time (LLT) and lower serum cortisol level in comparison with the S. aureus group. Moreover, there were significant changes in the gross lesion score and histopathological lesions between the different groups. In conclusion, the dietary supplementation of ZONPs can reduce S. aureus-induced negative effects of FPD in broilers.