Utilisation of straw supplemented with mineral mixture, concentrate mixture and UMMB lick was studied in buffaloes using; in vitro gas production technique which is an index of ruminal microbial activity. Twenty rumen fistulated Murrah males were divided in 5 groups of 4 each. In group I only paddy straw ad lib was provided while in group II concentrate mixture at maintenance level was given. In group III, IV and V, concentrate mixture was replaced by urea molasses mineral block (UMMR) ‘Ex’, ‘C’ and ‘D’ respectively. Total gas produced by untreated and urea treated paddy and wheat straw was significantly higher in groups II, III, IV and V as compared to group I, however, no significant differences were observed among four groups. This indicated that replacing concentrate mixture by UMMB at maintenance level would not affect microbial activity in rumen.
