Significance of “GRAS” Fungi in the Fermentation and Enrichment of Cassava Peels for the Production of Low Cost Feeds for Poultry and Domestic Animals

This study used solid-state fermentation methods to nutritionally enhance cassava peel using a strain of Aspergillus niger, Trichoderma viride and Saccharomyces cerevisiae. Cassava peel were collected, dried and made into crunches. This was fermented for 14 days at room temperature and oven dried. Fermented and unfermented crisp of the peels was analysed for crude protein, fat, fibre, dried matter and cyanides. Analysis of the dried fermented peels revealed that there was a significant increase in the protein and decrease in cyanides content of the cassava peel and there were differences in enrichment potency of the test fungi. Protein increased by 50% and cyanide reduced from 46.28mg/kg to 34.85mg/kg when treated with S. cerevisiae while treatment with Aspergillus niger resulted in more than 90% reduction in cyanides and increased the protein content from 6.25% to 13.39% when compared with the unfermented cassava peels, which had 46.28mg/kg cyanide. Fermentation with T. viride resulted in more than 90% reduction in cyanides and increased the protein content from 6.25% to 17.06% when compared with the unfermented cassava peels, which had 46.28mg/kg cyanide. In synergy, fungi fermentation shows slight incremental effect in protein and further reduced cyanide concentration. With the increase achieved in the protein content and the significant decrease in the residual cyanide of cassava peels fermented with these fungi, the end-product could be a good protein supplement in livestock feed production and this method if adequately adopted will help to reduce the cost of livestock feed production, increase the affordability of animal protein and then reduce the menace of agricultural waste pollution in the environment.