ABSTRACT LEONILO D. BACOLOD, LORENA A. DIZON, ANJANETTE P. MARIMLA., JULY 2022 EFFECT OF PROBIOTICS ON COBBS00 BROILER FED DIET SUBTITUTED WITH VARYING LEVELS OF SWEET POTATO (Ipomea batatas) LEAF MEAL Bachelor of Science in Agriculture major in Animal Science. Pampanga State Agricultural University, PAC, Magalang, Pampanga. Adviser: JOANARCH C. BRIONES, M.S.A The study was conducted to determine the effect of probiotics on the cobb500 broiler-fed diet substituted with varying levels of sweet potato leaf meal. It was conducted from May 13, 2022 to July 17, 2022 at Escaler, Magalang, Pampanga. One hundred eighty (180) Cobb broilers were randomly distributed into two treatments replicated four times following the Randomized Completely Block Design. Each treatment was composed of thirty heads. The treatments were composed of 2 factors: AlB1 controls pure commercial feeds and pure water; A2B1-90% commercial feeds containing sweet potato leaf meal and pure water; and A3B1-85% commercial feeds containing 15% sweet potato leaf meal and pure water. AlB2 pure commercial feeds with probiotics per litter of water, AZ2B2 90% commercial feeds with 10% sweet potato leaf meal with probiotics per litter of water, and A3B2 85% pure commercial feeds with 15% sweet potato leaf meal with probiotics per litter of water will be Factor B. No significant differences were noted in all parameters considered.