Ethanolic extract of Polygonatum sibiricum fibrous root improves growth performance, antioxidant status, intestinal morphology, and cecal fermentation in yellow-feathered broilers.

This study systematically evaluated the effects of dietary supplementation with an ethanolic extract of Polygonatum sibiricum fibrous root (PFRE) on growth performance, carcass traits, meat quality, antioxidant status, intestinal morphology, cecal short-chain fatty acids (SCFAs), and microbiota in yellow-feathered broilers. A total of 200 one-day-old yellow-feathered broilers were randomly assigned to four diets (5 replicates of 10 broilers each). The control group received a basal diet, while the experimental groups were supplemented with 400, 800, and 1,600 mg/kg PFRE, respectively, with an experimental period of 56 days. The results showed that body weight (P < 0.05) and ADG (P < 0.05) were greater at 800 and 1,600 mg/kg than in the control group in the 1 ∼ 28 days of age. Over the entire trial, PFRE increased (P < 0.05) final body weight and ADG, whereas F/G was lower (P = 0.008) at 400 and 1,600 mg/kg. Semi-eviscerated yield increased and breast muscle shear force decreased with PFRE supplementation (P < 0.001). Serum, hepatic, and jejunal malondialdehyde concentrations were reduced (P < 0.001), although other antioxidant indices showed tissue and supplementation level specific responses. Jejunal villus height increased at 800 and 1,600 mg/kg (P < 0.001). Acetic acid, propionic acid, isobutyric acid, butyric acid, and valeric acid concentrations increased (P < 0.05), whereas alpha and overall beta diversity were unaffected (P > 0.05). Several bacterial genera differed among treatments and were associated with SCFAs and host phenotypic indexes. In conclusion, dietary supplementation with PFRE significantly enhanced growth performance, decreased lipid peroxidation, modified intestinal morphology, and improved cecal fermentation in yellow‑feathered broilers. The 800 mg/kg level produced the most balanced overall responses among the doses tested.