ABSTRACT JOHN KENNETH M. CABRERA, RENDELLE M. CRUZ, RAM RAEL M. LACANLALE July 2022. GROWTH PERFORMANCE OF COBB BROILERS ON VARIOUS LEVELS OF OYSTER MUSHROOM (Pleurotus ostreatus) MIXED IN COMMERCIAL FEEDS. Bachelor of Science in Agriculture major in Animal Science. Pampanga State Agricultural University, PAC, Magalang, Pampanga. Adviser: JOEL C. SALAZAR, Ph.D. The study aimed to determine the growth performance of Cobb broilers fed with different commercial feeds supplemented with oyster mushroom. One hundred and eighty broiler chicks were used to evaluate the effect various level of oyster mushroom. A factorial arranged in randomized complete block design were used and analyzed through analysis of variance (ANOVA). Twenty-five percent (25%) inclusion of oyster mushroom meal (OMM) in the dietary ration of broiler chickens showed significant effect on the biological growth of the broilers. It was also revealed that growth parameters (final weight, gain in weight, ADG and FCR) supplemented with 25% OMM were statistically highly significant at 1%% level. In conclusion, dietary inclusion of oyster mushroom meal at 25% level on its ration had a significant outcome on the growth performance of broilers.