Effect of dietary Lycium barbarum polysaccharide on growth performance and immune function of broilers

Lycium barbarum polysaccharide (LBP) is a traditional Chinese herbal medicine possessing many properties such as anti-oxidant and immunomodulation. This study was conducted to evaluate the clinical efficacy of LBP in broilers. A total of 240 newly hatched broilers were randomly allotted into 4 treatments with 6 replicates. Diets in 3 treatment groups were supplemented with 2, 4, and 8 g/kg LBP, respectively, based on the control diet. Lymphocytes isolated from broiler blood were used to detect immunoregulation function of LBP in vitro. Results in vivo showed that average daily feed intake (ADFI) and feed conversion ratio (FCR) in the 4 g/kg LBP group were decreased significantly (P < 0.05). Dietary 4 g/kg LBP significantly increased immune organ indexes of broilers at 21 d (P < 0.05). Moreover, levels of serum total protein, globulin, albumin, and lysozyme of broilers were higher in the 8 g/kg LBP group (P < 0.05). CD4+/CD8+ ratio in blood T cells was higher in the 4 g/kg LBP group (P < 0.05). Results in vitro suggested that 100 and 1,600 mu g/mL LBP supplementation significantly promoted blood B and T lymphocyte proliferation of broilers, respectively (P< 0.05). TNF-alpha mRNAabundance was observably decreased in the lower LBP concentration groups (P < 0.05). In conclusion, LBP may possess the clinical efficacy for growth promotion and immunomodulation and could be used as an alternative for nutritive additive in broilers.