This study investigated the effects of dietary Arginine ( Arg ) on performance, intestinal antioxidative capacity, immunity, and gut microbiota in Chinese yellow-feathered chickens. One thousand two hundred 1-day-old female Qingyuan partridge chickens were randomly assigned to 5 groups with 6 replicates of 40 birds each. Chickens were fed diets with 5 levels of total Arg (8.5, 9.7, 10.9, 12.1, and 13.3 g/kg) without antibiotics for 30 d. The ADFI, ADG, and feed conversion ratio were improved with dietary Arg levels ( P < 0.05). The proportions of CD3 + and CD4 + /CD8 + lymphocytes responded in a linear ( P < 0.05) manner and those of CD4 + in a linear or quadratic ( P < 0.05) manner as dietary Arg levels increased. Dietary Arg level had a linear ( P < 0.05) or quadratic ( P < 0.05) effect on the gene expression of glutathione peroxidase 1, heme oxygenase 1, nuclear factor erythroid 2–related factor 2, and the activities of glutathione peroxidase and total antioxidative capacity in the jejunum and ileum. The relative expression of IL-1β, myeloid differentiation primary response 88, and Toll-like receptor 4 decreased linearly ( P < 0.05) in the ileum with increasing dietary Arg levels; secretory IgA contents were increased. In addition, sequencing data of 16S rRNA indicated that dietary Arg increased the relative abundance of Firmicutes phylum, Romboutsia and Candidatus Arthromitus genera, while decreased that of Clostridium sensu stricto 1 . A diet containing 12.1 g Arg/kg promoted growth performance, intestinal antioxidation, and innate immunity and modulated gut microbiota in yellow-feathered chickens.

A series of MnO x -CeO 2 and MnO x -TiO 2 catalysts were prepared by a homogeneous precipitation method and their catalytic activities for the NO oxidation in the absence or presence of SO 2 were evaluated. Results show that the optimal molar ratio of Mn/Ce and Mn/Ti are 0.7 and 0.5, respectively. The MnO x -CeO 2 catalyst exhibits higher catalytic activity and better resistance to SO 2 poisoning than the MnO x -TiO 2 catalyst. On the basis of Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and scanning transmission electron microscope with mapping (STEM-mapping) analyses, it is seen that the MnO x -CeO 2 catalyst possesses higher BET surface area and better dispersion of MnO x over the catalyst than MnO x -TiO 2 catalyst. X-ray photoelectron spectroscopy (XPS) measurements reveal that MnO x -CeO 2 catalyst provides the abundance of Mn 3+ and more surface adsorbed oxygen, and SO 2 might be preferentially adsorbed to the surface of CeO 2 to form sulfate species, which provides a protection of MnO x active sites from being poisoned. In contrast, MnO x active sites over the MnO x -TiO 2 catalyst are easily and quickly sulfated, leading to rapid deactivation of the catalyst for NO oxidation. Furthermore, temperature programmed desorption with NO and O 2 (NO + O 2 -TPD) and in situ diffuse reflectance infrared transform spectroscopy (in situ DRIFTS) characterizations results show that the MnO x -CeO 2 catalyst displays much stronger ability to adsorb NO x than the MnO x -TiO 2 catalyst, especially after SO 2 poisoning.

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