Curculigo orchioides Polysaccharide Promotes the Growth and Development of Wenchang Chickens via the PI3K/Akt/mTOR...

Previous studies have demonstrated that polysaccharides used as feed additives can promote poultry growth. This study evaluated the effects of different doses of Curculigo orchioides Polysaccharide (COP) on growth performance, antioxidant capacity, immune function, intestinal health and related mechanisms in 1 to 35 days old Wenchang female chicks. A total of 120 female Wenchang chickens (1 day old) were assigned to three treatment groups, with 5 replicates per group and 8 chickens per replicate. The Wenchang chickens were fed a basal diet (control) supplemented with either a low dose of Curculigo orchioides Polysaccharide (400 mg/kg) or a high dose (800 mg/kg) for 5 weeks. Purified COP is composed of mannose (68.97%), glucose (24.38%), galactose (6.34%), and arabinose (0.32%). Results showed that high-dose COP supplementation significantly increased Wenchang chicken body weight (p < 0.05) and feed intake (p < 0.05); reduced feed conversion ratio (p < 0.05); increased small intestinal villus height and tight junction protein expression levels; enhanced muscle fiber cross-sectional area (p < 0.05); improved total antioxidant capacity (p < 0.01); decreased serum malondialdehyde levels (p < 0.01), tumor necrosis factor-α (p < 0.0001), and pro-inflammatory cytokine interleukin-6 levels (p < 0.05); and elevated antibody titers against Newcastle disease virus at 21, 28, and 35 days (p < 0.01). It also elevated the protein phosphorylation levels of the PI3K/Akt/mTOR pathway (p < 0.0001) and enriched beneficial gut microbiota that may mediate this pathway activation. Analysis of the cecal microbiota in Wenchang female chicks revealed that the high-dose COP group enriched Oscillospira and Lactobacillus. In conclusion, high-dose COP improves growth performance and antioxidant capacity of Wenchang chicks, enhances immunity against NDV, enriches beneficial gut microbiota, and promotes growth by activating the PI3K/Akt/mTOR pathway.