The aim of this study was to in vitro evaluate encapsulated probiotic supplementation to ruminant rationson degradation and fermentation parameters. The ration consisted of 40% alfalfa hay and 60% concentrate feed mixture. Encapsulated and not encapsulated probiotic were supplemented with level of 106cfu/kg of the total dry matter of ration (DM) and compared with encapsulation media (Sodium Alginate, SA) and control (not supplemented ration). DM and OM degradation and total gas production as well as fermentation parameters of the incubated samples were determined after 24 h of fermentation. Significant (P<0.01) increases in in-vitro DM degradability was observed for the experimental ration supplemented with encapsulated or not encapsulated probiotics at levels (106 CFU/ kg DM) and SA treatment compared to control ration. Also, significant (P<0.05) improvement in OM degradability was recorded for the ration supplemented with not encapsulated probiotics bacteria compared to the other treatments. Moreover no significant differences were observed between the control ration and the rations supplemented with encapsulated probiotics or SA only, as well as no significant difference was recorded between the ration supplemented with encapsulated probiotics and the ration supplemented with SA only. Probiotics bacteria supple mentation in the form of not encapsulated probiotic resulted significant increases in in vitro total gas production per sample and per g DM, OM, dDM, NDF and ADF after 24 hours incubation period compared to the other experimental rations (control, encapsulated probiotic and SA). While significant increase in total gas production per g dOM was observed for not encapsulated probiotic compared to encapsulated probiotic only. It could be concluded that, using encapsulated probiotics bacteria had no significant effect on DM degradability and may be induce decrease in gas production and fermentation parameters.