Abstract: 【Objective】 This experiment was conducted to investigate the effects of dietary berberine (BBR) on organ indexes, intestinal antioxidant capacity and intestinal immunity in Yellow-feathered broilers.【Method】 A total of 360 one-day-old Yellow-feathered chickens were randomly divided into 3 groups with 6 replicates in each group and 20 chickens in each replicate.The control group (NC) was fed with basal diet, the antibiotic group (PC) was fed with basal diet +200 mg/kg oxytetracycline calcium +250 mg/kg nasitide, the berberine group (BBR) was fed basal diet +250 mg/kg BBR.At 21, 42 and 63 d, one chick with the similar average body weight from each replicate was randomly selected and sacrificed.The heart, liver, spleen and bursa of Fabricius were collected and weighed respectively.The weight was recorded and the organ index was calculated.The jejunal mucosa was scraped to determine the activities of superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px), as well as the maldialaldehyde (MDA) content.The total RNA was extracted from jejunal mucosa and synthesized for cDNA to determine the mRNA expression of the tight junction proteins and the inflammatory cytokines.【Result】 There was no significant difference in the indexes of organs among groups (P>0.05).Compared with NC group, the total antioxidant capacity (T-AOC) was significantly increased and the content of malondialdehyde (MDA) was significantly decreased by dietary BBR supplementation in jejunal mucosa of Yellow-feathered broilers at 63 d (P<0.05).The mRNA expression of Occludin and zonula occludens-1 (ZO-1) in jejunal mucosa was significantly higher in PC group compared with those in NC group and BBR groups at 21 d (P<0.05).Compared to NC and PC groups, the mRNA expression of Claudin-1 in the jejunal mucosa of Yellow-feathered broilers at 63 d was significantly higher in BBR group (P<0.05), and the mRNA expression of nucleotide-binding oligomerization domain-containing protein 1 (NOD1) at 21 and 42 d was significantly down-regulated in BBR groups (P<0.05).Moreover, the mRNA expression of interleukin-1β (IL-1β) and IL-8 (IL-8) of Yellow-feather broilers was decreased in BBR and PC groups when compared with PC at 42 d (P<0.05).Compared to NC group, the mRNA expression of tumor necrosis factor-α (TNF-α), IL-1β, and IL-8 was decreased in BBR group at 63 d (P<0.05).【Conclusion】 The addition of 250 mg/kg berberine to the diet could enhance the intestinal antioxidant capacity, improve the intestinal barrier and reduce the expression of intestinal inflammatory factors in Yellow-feathered broilers at 63 d, so as to improve the intestinal immune function.

Key words: berberine; Yellow-feathered broiler; intestinal barrier; gene expression; antioxidant capacity; intestinal immunity