Growth Performance, Meat Quality, Lipid Profile and Residue Status of Broiler Chickens Supplemented with Polyalthia longifolia Ethanolic Leaf Extract Powder

Abstract

Background: The withdrawal of antibiotic growth promoters (AGPs) in poultry production has intensified the search for safe, natural alternatives that support both productivity and meat safety. Aim: This study evaluated the efficacy of Polyalthia longifolia Ethanolic Leaf Extract Powder (PlELEP) as a phytogenic substitute for ciprofloxacin in broiler chickens, with emphasis on growth performance, carcass traits, and comprehensive meat quality parameters. Place and Duration of Study: The study was carried out at the Teaching and Research Farm of the University of Ibadan, Ibadan, Nigeria, between January and April, 2020. Materials and Methods: A total of 210 one-day-old Arbor Acres broiler chicks were randomly assigned to five treatments (n = 42/treatment): negative control (no additive), positive control (10 mg/L ciprofloxacin in water), and three PlELEP-supplemented groups (1, 2, and 3 g/L in drinking water). The trial lasted 42 days, with PlELEP or ciprofloxacin administered intermittently during grower and finisher phases. At slaughter, breast meat was analysed for physicochemical properties, lipid profile, and residues of antioxidants and antibiotics. Results: Dietary supplementation with 3 g/L PlELEP significantly improved average daily gain (43.64 g) and feed conversion ratio (1.99) compared to the negative control (42.92 g; FCR = 2.14; p < 0.05), matching the performance of the ciprofloxacin group. Dietary PlELEP supplementation did not alter carcass traits. PlELEP at 3 g/L also enhanced meat quality, yielded lower ultimate pH (5.83), higher water-holding capacity (73.96%), and reduced cooking loss (28.37%) relative to controls. Furthermore, breast meat from this group exhibited the most favourable lipid profile, lowest total cholesterol (83.23 mg/dL) and triglycerides (110.55 mg/dL), highest HDL (52.14 mg/dL), and elevated endogenous phenolic (1.24 mg GAE/g) and flavonoid (1.96 mg quercetin/g) content. Critically, Ciprofloxacin residues (35.33 µg/kg) were confirmed in the positive control. Conclusion: Polyalthia longifolia ethanolic leaf extract, particularly at 3 g/L, functioned as a multifunctional, residue-free alternative to conventional AGPs, simultaneously enhancing growth efficiency, improving key meat quality attributes, and enriching nutritional and antioxidant profiles.