LAUSR

This study aimed to investigate the effects of dietary Astragalus membranaceus polysaccharide (AMP) supplementation on the growth performance and immunity of juvenile broilers. High-performance liquid chromatography spectrum and sugar composition analysis indicated that AMP is a heteropolysaccharide with a molecular weight of 11,078 Da and consists of glucose, galactose, rhamnose, and arabinose. Four diets supplemented with four different levels of AMP (0, 0.5, 1, and 2 g kg-1) were formulated and tested for their effects on the growth performance and immunity of juvenile broilers. After 6 wk of feeding, the juvenile broilers fed with AMP-containing diets exhibited higher body weight gains; the activities of digestive enzymes (amylase, lipase, and protease), superoxide dismutase and glutathione peroxidase; and serum IgG, IgM, and IgA levels; and lower malondialdehyde level than the control. However, excessive AMP dose (>1 g kg-1) could not improve its efficiency further. Results indicate that dietary administration of AMP can improve the growth performance and immune responses of juvenile broilers.