This study investigated the effects of dietary supplementation with different levels of Broussonetia papyrifera (BP) leave on growth performance, serum antioxidant status, and serum metabolites in broilers. A total of 240 one-day-old broilers were randomly allocated to four treatments with three replicates of 20 birds each in a single-factor design. Birds in the control group were fed a basal diet, while those in groups B1, B2, and B3 were fed diets in which soybean meal was replaced with 4, 8 and 12% BP leaves, respectively. After a 42-day feeding trial, blood samples were collected from the subclavian vein for serum analysis. Results showed that 4% BP leaves had no adverse effect on broiler growth performance and improved immune organ indices compared with the control, whereas higher inclusion levels reduced growth performance. The 4% BP leaf group exhibited significantly increased serum T-AOC, GSH-PX, and CAT levels. Both 4% and 8% BP leaf groups presented higher SOD activity and lower MDA content than the control. Overall, 4% and 8% BP leaf supplementation (B1, B2) exerted favorable antioxidant and anti-damage effects and were considered optimal levels. LC-MS/MS‑based untargeted metabolomics revealed that α‑ketoglutarate, L‑lysine and other key differential metabolites were notably enriched in pathways including alanine, aspartate and glutamate metabolism, and the tricarboxylic acid cycle. Metabolic regulation was relatively weak in the 4% BP leaf group, whereas the 8% group showed the most significant pathway enrichment and optimal metabolic balance among energy generation, amino acid utilization, and antioxidant capacity. Conversely, metabolic pathway disturbance was observed in the 12% group.

To Cite This Article: Huang W, Mei F, Behan AA, Zhang T, AL-Essa LA, Al-Rasheed M, Taha R, Cao ZY and Yang X, 2026. Effect of Broussonetia papyrifera leaves on serum antioxidants and metabolites in broilers. Pak Vet J, 46(4): 1028-1038. http://dx.doi.org/10.29261/pakvetj/2026.084