The rice gruel was compared with molasses as source of readily fermentable energy for their effectiveness on the physiology of the rumen and the growth performance of growing calves with mean age of 20 months and mean body weight of 193.3± 12.01 Kg. At the end of the 60 days feeding trial, no significant differences could be found between the two groups in the gain in body weight. . The pH of the rumen liquor peaked 12 h post feeding among both groups receiving rice gruel or molasses; while lowest pH value was attained at 20 h among the group receiving the rice gruel, and at 16 h post feeding among the calves groups receiving molasses. The bacterial population (cell x1010) ranged from 5.2 to 8.1 in the rice gruel group and was higher (range between7.3 to 9.7) in the Group consuming molasses. II with respective peak counts at 12 h and 20 h. The rumen protozoal count behaved in a similar manner to that of rumen bacteria. In conclusion, similar effectiveness of rice gruel and molasses as fermentable energy source. Rice gruel can replace molasses as energy source under situation when molasses are not available. 1421240858.php