Amongst the feeds experimented in Rumen Simulation Technique (RUSITEC), the disappearance was more in the control feed, EFFBW and EFDBW when compared to other experimental feeds. Similarly, the disappearance was more in BWIPS compared to paddy straw. The in vitro DM, CP, CF, NDF, ADF, hemicellulose and cellulose disappearance at all incubation periods were higher for FBW than the DBW. The FBW had more disappearance compared to DBW. The rumen fermentation parameters such as pH, total gas production, CO2 production, NH3-N, TVFA and their fractions such as acetate, propionate, iso butyrate, butyrate and valerate concentration and the in vitro rumen effective degradability of DM and CP of experimental feeds were also analyzed in RUSITEC.