Dietary L-arginine supplementation enhances growth performance, intestinal antioxidative capacity, immunity and modulates gut microbiota in yellow-feathered chickens

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.