The results of the study of Chanjula et al. (2003) demonstrated that the ruminal disappearance characteristics of seven feeds differed among feeds and that CC had the greatest retention time (Table 3). The content of DM and OM disappearance ranked from the highest to the lowest of rate of degradation (c) were as follows: CC, yellow sweet potato, purple sweet potato, white sweet potato, cassava waste, corn meal and rice bran, respectively. These values could potentially be used in synchronizing degradation with the availability of NPN in the rumen to optimize ruminal availability of energy : protein to maximize microbial protein synthesis.