Dietary Silphium perfoliatum L. Flavonoid extract effects on carcass traits, serum biochemistry, breast meat quality, and myogenic gene expression in broiler chickens.

Silphium perfoliatum L. (cup plant) is a flavonoid-containing forage species with potential as a phytogenic feed additive, but its effects on carcass and meat-quality outcomes in broilers remain poorly characterized. This study evaluated dietary supplementation with a flavonoid-rich S. perfoliatum extract (SPL) on carcass traits, serum biochemical indices, breast-meat quality, muscle histomorphology, and myogenic gene expression. A total of 240 Arbor Acres broilers were assigned to four dietary treatments: a basal diet (CON) or the basal diet supplemented with 100, 200, or 300 mg/kg SPL (SPL100, SPL200, and SPL300, respectively). The feeding trial lasted 42 experimental days following an initial 3-day pre-experimental adaptation period. Among carcass traits, eviscerated yield was higher in SPL100, and leg-muscle percentage was higher in the supplemented groups; however, abdominal-fat percentage also increased. SPL decreased serum triglycerides but increased total cholesterol. Serum albumin was elevated in SPL100 relative to the control, whereas SPL300 showed intermediate albumin concentrations that did not differ significantly from CON. Breast-muscle pH at 45 min and 24 h postmortem was higher, whereas yellowness (b*) and shear force were lower in the SPL groups. Fiber diameter was lower in SPL100, whereas fiber cross-sectional area was unchanged. Reanalysis of all four biological observations represented in the archived qPCR dataset per treatment detected no significant treatment effect on MSTN, IGF-I, Myf5, or MyoG expression. Overall, dietary SPL was associated with selective changes in carcass traits, serum biochemical indices, and breast-meat quality, while the transcriptional data did not support a definitive myogenic mechanism. The increases in abdominal fat and total cholesterol warrant further investigation.