This paper focuses on treated date seed with two cellulolytic bacteria (Acetobacter xylinum and Thermonospora fusca) isolated from sheep and evaluated these species by Invitro gas production and metabolism trail.  We evaluated the influence of many rations contain several percentage from date seed untreated and treated on In vitro traild for DM,OM, NDF, ADF, cellulose and hemicellulose disappeara (samples incubated for 24 hrs). the best ration used in metabolism trail . The experimental work was conducted in 2017, at the Department of Animal Production, faculty of agriculture, Ain Shams University, Cairo, Egypt and the experiment of the farm animals occurred in the Animal Production research institute.  Our results in this revealed that the ration content 25% untreated and treated with bacteria  had significant values on NDF, ADF and hemicellulose degradability after 24 hours, especially treatment 2 (Thermonospora fusca) of date seed. In  the experimental ration with ascending level of untreated and treated date seed  had not significant effect on pH value while more effect on total gas production (GP),ammonia, TVFA’s, MP, EMP and  metabolizable energy ME (Mcal/ g). The differences were significant (P<0.05) between control ration and other experimental  rations. Furthermore, ration content date seed treated (R3) had the highest values of DM, OM, CF and EE digestibility. It could be noticed that improving CP, CF and cell wall constituents (NDF, ADF, hemicellulose and cellulose) digestibility may be due to the increasing number of rumen cellulolytic bacteria. In conclusion, the bacterial treatment (Acetobacter xylinum and Thermonospora fusca) with date seed successfully to improve chemical compostion of date seed and Invitro digestiability specially ration contain 25% from total dry matter.  It showed that the strain (Thermonospora fusca) was  the best in In vitro fermentation . Digestibility indicated that ration contain treated date seed (R3) was high DM, OM, ADF and nitrogen than other rations.  It was concluded that treated date seed can replace concentrate in rations and improve In vitro degradability, digestibility trail and no effect on rumen and blood parameters without adversely affecting on helthy animals.