Abstract: The aim of this study was to evaluate the effects of additives on in vitro Gas Production (IVGP), IVGP kinetics, energy values, Organic Matter Digestibility (OMD) and Dry Matter Digestibility (DMD) of Sugar Beet Pulp Silage (SBPS). Eight different silages were prepared form the sugar beet pulp samples. Silage treatments included no additives (CONT), Artturi Imarin Virtanen solution (AIV), feed urea (UREA), Formic Acid (FAS), biological inoculants Maize All (MAL) and Sil All (SAL), F silofarm formiat dry (SFD) and F Silofarm Liquid (SLI). The effects of different silage additives were determined using IVGP technique and pepsin-cellulase method in this study. Three Sakiz x Karayaka rams aged 2 years with ruminal cannulas were used IVGP technique. In vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD) and energy values were studied by using pepsin-cellulase method. The silage additives significantly affected the nutrient contents of SBPS (p<0.01). The highest crude protein content was found in UREA treated silages. Highest values in terms of NFE were determined in FAS treated silages (p<0.01). The IVGP of AIV treated silages were significantly lower than those of silages applied for other treatments at 24, 48, 72 and 96 h incubations (p<0.01). Biological inoculants (MAL and SAL), SLI and SFD treatments resulted in the highest energy values and IVGP. In conclusion, the use of IVGP technique can be recommended in the estimation of ME and NEL values of SBPS since this technique provides more reliable estimates as compared to pepsin-cellulase method.