Rutin ameliorates cold stress-induced impairment of growth performance, intestinal barrier function and cecal microbiota in broiler chickens.

This study aimed to investigate the effects of rutin on growth performance, intestinal barrier function, and gut microbiota in broilers under cold stress. A total of 360 one-day-old male broilers with an average body weight of 39 ± 2 g were randomly allocated into four groups. (6 replicates per treatment, 15 birds per replicate): CON (thermoneutral, basal diet), CS (cold stress control), CSR500 (500 mg rutin/kg diet), and CSR1000 (1000 mg rutin/kg diet). On day 28, one male bird per replicate, with body weight within ±5% of the group mean, was selected to represent the replicate, fasted for 12 hours, and then sampled. Serum, ileal tissue, and cecal content samples were collected for further analysis. Dietary supplementation of rutin significantly improved average daily gain (ADG) and feed conversion ratio (FCR) (p < 0.05) in cold-stressed broilers. It also enhanced immune organ indices and serum immunoglobulin levels (p < 0.05). Rutin significantly enhanced antioxidant capacity of ileal tissue, markedly increasing the activities of total superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) (p < 0.05), while reducing malondialdehyde (MDA) content. Rutin alleviated intestinal injury, which may be associated with modulation of intestinal permeability and inflammatory signaling pathways, repairing the intestinal mucosal and mechanical barriers associated with the Notch-1 signaling pathway, suppressing the activation of the NF-κB pathway and the expression of inflammatory cytokines. Additionally, rutin optimized the gut microbial structure by reducing the abundance of harmful bacteria (e.g., Proteobacteria) and increasing beneficial bacteria (e.g., Bacteroides). In conclusion, rutin alleviates the adverse effects of cold stress on broiler growth performance and improves intestinal health through specify mechanisms, offering a novel feed additive strategy for mitigating cold stress in poultry production.