Pleurotus ostreatus extract inhibits Eimeria species development in naturally infected broiler chickens

Coccidian organisms of poultry have proved very hard to control due to their abilities to resist most anticoccidial drugs. Pleurotus ostreatus (Fr.) Jacq. ex (Pleurotaceae), a medicinal mushroom, was investigated in vivo against Eimeria spp. Ninety-six broilers (day-old) naturally infected with Eimeria spp. were divided into eight groups (12 birds per group). Group A was infected untreated (negative control) and group B was treated with toltrazuril (positive control) while groups C-H were gavaged with graded doses of P. ostreatus extract at 100, 200, 300, 400, 500, and 600mg/kg, respectively. The phytochemical analysis of the aqueous extract of P. ostreatus which revealed saponins, flavonoids, anthraquinones, and alkaloids was evaluated for anticoccidial activity by assessing the inhibition of oocyst output, lesion score, faecal score, weight differences, haematological parameters, and leucocyte differential counts. The acute toxicity study showed extract of P. ostreatus to be non-toxic at 600mg/kg. The weight of the groups treated with the extracts and toltrazuril increased significantly (P<0.05) compared with the untreated control. Treated groups significantly (P<0.05) reduced oocyst output except groups C and D. The therapeutic best-fit ED50 value for the extract was 448mg/kg. The post-treatment mean packed cell volume and red blood cell count were significantly higher (P<0.05) than the untreated group, while the WBC count was significantly higher (P<0.05) in the untreated group. Pleurotus ostreatus therefore could be a potential source of new anticoccidial medicine which could find application in the control of avian coccidiosis.