Abstract: Background and Objective: The increased aesthetic nuisance caused by cassava root sievate has been a major concern to environmentalists and animal scientists in discovering means of adding value to this agro-waste. The study aimed to evaluate the nutritional, anti-nutritional, in vitro gas production and fermentation characteristics of biodegraded and non-biodegraded cassava root sievate for goats. Materials and Methods: Pleurotus tuber-regium, Pleurotus pulmonarius, Pleurotus ostreatus and Pleurotus eryngii, were used to treat cassava root sievate for 45 days. The nutritional, in vitro gas production and fermentation characteristics of the biodegraded and non-biodegraded cassava root sievate, were evaluated. Results: The results showed that biodegraded cassava root sievate (BCRS) were significantly (p>0.05) higher in crude protein (CP), ash, nitrogen-free extract (NFE) and calcium while non-biodegraded cassava root sievate (NBCRS) were higher (p>0.05) in ether extract (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), hydrogen cyanide (HCN) tannins, saponins. BSCR produced significantly higher (p>0.05) in vitro gas at 6, 12 and 24 hrs incubation time. Organic matter digestibility (OMD), in vitro dry matter digestibility (IVDMD), short-chain fatty acid (SCFA) and metabolisable energy (ME) were significantly (p>0.05) higher for the BSCR. Conclusion: It could be concluded that the use of white-rot fungi for biodegradation improved the quality and feeding value of cassava root sievate.