Effects of graded levels Citri Reticulatae Pericarpium (Chenpi) on growth performance, serum biochemical indices, meat quality, and caecal microbiota and metabolite in yellow-feathered broilers

The Citri Reticulatae Pericarpium (CRP), is the aged peel of Citrus fruit, which contains phenols, flavonoids, and polysaccharides. This study aims to investigate dietary CRP supplementation on the growth performance, serum biochemical indices, meat quality, intestinal morphology, microbiota, and metabolite of yellow-feathered broilers. A total of 240 yellow-feathered broilers (1.00 ± 0.22 kg, 9 weeks old) were randomly allotted into 4 treatments feeding a basal diet (control), the basal diet containing antibiotics (positive control), and the control diet containing 1.5% and 3% CRP, respectively. At the end of a 56-day trial, one broiler from each replicate was selected, and samples of ileal tissue and cecal digesta were collected to analyze intestinal morphology, microbial composition, and metabolites. The results revealed that 3% CRP decreased average daily feed intake (ADFI), serum total cholesterol (TC), and low-density lipoprotein (LDL). The CRP supplementation could increase serum superoxide dismutase (SOD) and meat pH. Broilers fed CRP had elevated antioxidant and liquid-regulated metabolites. Together, the results suggested that incorporating a moderate level of CRP has a minor impact on growth performance and could benefit health to some extent by enhancing antioxidants, regulating serum liquid, and changing microbial composition and metabolites.