Probiotics present an attractive alternative to the use of chemical and hormonal promoters in the livestock growth production industry. Preparations that contain micro-organisms have been safely used for many years and are generally accepted by both the farmer and the final consumer. Saccharomyces cerevisiae supplementation in ruminant diets can increase DMI, production performance, cellulose degradation, and nutrient digestibility (Callaway and Martin, 1997). The gas measuring technique has been widely used for the evaluation of nutritive value of feeds. Gas measurement provides useful data on digestion kinetics of both soluble and insoluble fractions of feedstuffs (Getachew et al., 1998). In the gas method, kinetics of fermentation can be studied on a single sample and therefore a relatively small amount of sample is required or a larger number of samples can be evaluated at time. The purpose of this study was to study effect of adding different levels of Saccharomyces cerevisiae on in vitro gas production from a dried grape by-product.