An in vitro evaluation of Pleurotus ostreatus EM-1-modified maize (zea mays) cob as a non-conventional energy source for livestock in Ghana

Abstract

Treatment with Pleurotus ostreatus strain EM-1 recently has been proposed as an effective means of transforming maize cob into nutritive animal feed for livestock production in the West African sub-region. This study compares P. ostreatus strain EM-1-treated maize cob with peels of cassava and plantain, widely-accepted complementary feedstuffs in West Africa, in terms of in vitro biodegradability and composition. Subjection of milled maize cob samples to solid state fermentation by P. ostreatus strain EM-1, until complete mycelial colonization, resulted in an increase of 107.3% in cell extractives and a 41.2% reduction in lignin content. The cellulose content of the treated maize cob exceeded that of plantain peel and cassava peel by 44.9 and 71.2%, respectively, while protein and lipid content did not differ significantly from mean values obtained for cassava peel. Cellulosic sugar production from treated maize cob, measured at 37°C for up to 3 h in the presence or absence of 0.05 U mL-1 cellulase, surpassed that of cassava peel by 52.3% (p<0.05) but was significantly lower than that of plantain peel. The data indicate that the potential metabolizable energy of P. ostreatus strain EM-1-modified maize cob far exceeds that of cassava peel. Based on the present findings, maize cob treated with P. ostreatus strain EM-1 should serve as an excellent complementary energy source for small ruminants in the West African sub-region