Four total mixed rations prepared from finger millet straw as a roughage (48%) and mixed concentrate (52%), supplemented with 1 or 1.5% isoacids and protein (groundnut cake, 5% crude protein more than control) were given in a change-over experiment to sheep. Biochemical activities were estimated for enzymes e.g., urease, cellulase, protease, and amylase, in various fractions of rumen fluid. Rumen samples were fractionated by centrifugation in strained rumen fluid without protozoa (SRFWP), cell free rumen fluid (CFRF) and enzymes associated with the bacterial cell (EABC). Samples of SRFWP and EABC contained higher enzyme activity than CFRF. These values showed very close cooperative action between proteolytic and amylolytic bacteria under the experimental condition, or perhaps presence of some species of bacteria with both activities. Results showed isoacid and crude protein enhanced microbial function (P<0.05) and this can change the pattern of enzymes in the rumen of sheep.