Exploring the effects of astragalus polysaccharide food supplementation on growth performance, immunity, antioxidant capacity, and intestinal microflora in Chinese mitten crabs

Astragalus polysaccharide (APS) is the main active ingredient in astragalus membranaceus, which is composed of rhamnose, arabinose, xylose, mannose, galactose, and glucose. This research evaluated dietary addition with APS effects on growth, non-specific immune, antioxidant status and intestinal microbiota of Chinese mitten crabs. Altogether 288 crabs with intact appendages were irregularly assigned 12 crabs per replicate to 24 tanks with 6 replicates per treatment. Crabs were given a basal diet in different groups containing 0 (control group), 500, 1000, and 2000 mg/kg of APS, respectively. The results indicated that the dietary APS addition increased the specific growth rate and percentage weight gain, serum phenoloxidase and lysozyme activities, increased superoxide dismutase and glutathione peroxidase activities of serum and hepatopancreas, reduced the feed conversion ratio of Chinese mitten crabs (P