Abstract: The potential for the nutritional improvement of cassava root sieviate by microbial degradation using Aspergillus niger was investigated. The proximate constituents of the biodegraded CRS were significantly affected (p<0.01) while the fibre constituents were reduced. Layers fed on control were not (p>0.05) significantly different from those fed biodegraded diet in terms of body weight gain and feed consumption. Hen day production of layers on biodegraded compared favourably with control and were significantly higher than those fed undegraded diets . The metabolizable energy of layers fed biodegraded were significantly lower (p<0.05) than those on control but better than those fed undegraded diet. 10% mortality was recorded for layers on biodegraded possibly due to microbial contamination. It was concluded that biodegradation had favourable impact on the protein content of CRS but not on performance of the layers.