EN
This study was aimed to determine the influence of Pleurotus ostreatus on response of broil-er chicken. One hundred and eighty day-old broiler chicks (90 each of Cobb and Marshall strain) were administered extract of Pleurotus ostreatus at 0, 2000 and 4000 mg/litre water. Data were collected on performance, carcass attributes, faecal oocyte per gram (OPG) and caecum microbial (CM) population. At day 28, strain had effect (p < 0.05) on feed: gain (F:G) with better value ob-served in Cobb. At day 56, Cobb had higher (p < 0.05) final weight (FW), total weight gain (TWG) and daily weight gain (DWG) with lower F:G. Highest (p < 0.05) FW and lower F:G were ob-served in birds administered 2000 and 4000 mg l-1. Interaction had effect (p < 0.05) on FW, TWG, DWG and F:G with best value observed in Cobb administered 4000 mg l-1. Cobb recorded higher (p < 0.05) dressed weight (DW%), breast% and thigh%. Increasing Pleurotus level resulted in highest DW% and breast in both strains. OPG and CM was lowest at 4000 mg l-1 in both strains. The study therefore concluded that for optimal performance, Pleurotus can be adminis-tered at 4000 mg l-1