Abstract: This study was carried out to investigate the precision of rumen fluid of slaughtered sheep and cows as the inoculums in the in vitro digestibility technique and its comparison with in vivo apparent digestibility techniques for ten feeds. The following two in vitro and one in vivo technique were used. These were the in vitro slaughtered Sheep Rumen fluid Technique (SRT), the in vitro slaughtered Cattle Rumen fluid Technique (CRT) and the in vivo Apparent Digestion Technique (ADT). Results from this study indicate that SRT and CRT have potential to be used for predicting in vivo DM digestibility. However, more research is required to modify both SRT and CRT to get better regression equation with low RSD and high correlation coefficient.