The purpose of this study was to determine intestinal digestibility of residual components of cassava pulp solid state fermentation by Saccharomyces cerevisiae for animal feed. Three ruminally cannulated animal were used to measure in situ rumen Dry Matter (DM) and Crude Protein (CP) degradability characteristics of cassava pulp solid state fermentation by S. cerevisiae. Nylon bags containing 3 g (as fed basis) of each feed was immersed in duplicate at each time point in the ventral rumen of each goat for 2, 4, 8, 12, 24, 48 and 72 h. Rumen feed residues from bags of 16 h incubation were used for estimation of lower gut digestibility by the technique of in vitro pepsin-pancreatin digestion. The results of the chemical analysis indicated that fermentation was slightly improved Ruminal Undegradable Protein (RUP) of cassava pulp. The highest value of RUP was significantly differ (p<0.05) after 5 days of fermentation period. Ruminal undegradable protein content increased (p<0.05) with the addition of S. cerevisiae in cassava pulp. The present results indicate that fermented cassava pulp can improve protein content and ruminal undegradable protein content.