This study attempts to isolate a candidate growth promoter from the ovine paunch waste and scrutinize its effects on the production performance of broiler chickens as compared to mannan-oligosaccharide (MOS), a prebiotic, and lincomycin, an antibiotic growth promoter (AB). The paunch waste collected from slaughtered sheep was processed to remove particulate matter. The clarified liquid was then added to an excess of ethanol (1:9 ratio), and the resultant precipitate {(novel growth-promoting paunch extract (NGPE)} was collected, dried, and stored. increase in cell density for probiotic bacteria and (Log CFU/ml) were significantly higher ( < 0.01) in NGPE supplemented media (2.78 ± 0.11 and 2.77 ± 0.10) as compared to that on MOS (1.28 ± 0.05 and 2.49 ± 0.09) and glucose (1.09 ± 0.04 and 1.12 ± 0.04) supplemented media. In the in-vivo trial of six weeks duration with broiler chickens (Cobb-400), NGPE supplementation resulted in significantly higher growth in weeks IV ( < 0.05) and VI ( < 0.01) of age in comparison to MOS and AGP supplemented groups, a lower ( < 0.01) cumulative feed conversion ratio in comparison to MOS supplemented groups, and a higher ( < 0.01) cumulative protein efficiency ratio compared to MOS and AGP supplementation. NGPE supplementation also lowered lipid peroxidation ( < 0.01), increased reduced glutathione activity ( < 0.01) in chicken erythrocytes, and boosted the lactic acid bacteria count in the cecal contents ( < 0.01). This is the first report of the isolation of a paunch waste extract that increased the growth of probiotic bacteria and improved the production performance of broiler chickens.