The influence of three different feeds, wheat straw, sorghum and berseem, on total and cellulolytic bacterial counts in the buffalo rumen at different time intervals from 0 to 8 h after feeding was studied. Berseem feeding supported maximum growth of rumen bacteria in general and cellulolytic bacteria in particular. Wheat straw supported the poorest growth.The types of cellulolytic bacteria recovered from the rumen of adult buffaloes wereRuminococcus albus, R. flavefaciens, Bacteroides succinogenes, Butyrivibrio fibrisolvens, Clostridium lochheadii, Cl. longisporumand otherClostridiumspp. Cellulolytic cocci were present in smaller numbers than rod forms in the rumen of wheat‐straw‐fed buffaloes, whereas the cocci outnumbered rod forms in sorghum‐and berseem‐fed bu