Ameliorative effect of dietary supplementation of copper oxide nanoparticles on inflammatory and immune reponses in commercial broiler under normal and heat-stress housing conditions

摘要

Heat stress (HS) is one of the most serious adverse conditions that affect poultry causing immunosuppression and decreasing production. In a novel approach, we investigated effects of supplementing copper oxide nanoparticles (CuO-NPs) on the immune response in two commercial broiler strains (Ross 308 and Cobb 500). At one day old, birds were divided into 3 groups with 3 replicates for each. The first group received diet supplemented with 100% of their recommended copper requirements as CuO while, in the second and third groups, birds were given diets supplemented with 100% and 50% of the recommended Cu requirements in the form of CuO-NPs, respectively. At age of 21 day, each group was subdivided randomly into normal (24 +/- 2 degrees C) and heat stressed (33 +/- 2 degrees C for 5 h per day for two successive weeks) groups. Under normal housing temperature, CuO-NPs, significantly enhanced the immune response in these birds, compared to CuO shown by the increased levels of phagocytic activity (PA), lysozyme serum activity, and by upregulating immune-modulator genes including NF-kappa beta, PGES, IL-1 beta, TGF-1 beta, IFN-gamma, BAX and CASP8. The responses were different between the two studied strains especially at the level of gene expression. In HS birds, supplementation of CuO-NPs reduced HS induced inflammatory conditions, as shown by lower gene expression levels, lower degenerative changes in the spleen, and altered heterophils/lymphocytes (H/L) ratio. We suggest CuO-NPs supplementation, especially in those chickens that received diet supplemented with 50% of their recommended Cu requirements, could be used under normal housing temperature to enhance the birds' immune response, and during HS to lower heat stress-induced degenerative changes depending on the magnitude of the HS.