Total protozoal content was influenced by addition ofOA and treatment with PEG; however, there was no ten-dency for OA × PEG interaction regarding total protozoalpopulation. Isotricha, dasytricha and, diplodinium were notaffected by inclusion of OA but the trend for entodiniumand ophryoscolex was to be decreased (P < 0.10). There wasa significant effect on individual genera due to addition ofPEG to the diets (Table 5). No significant alterations wereobserved in cellulolytic and proteolytic bacteria followingincorporation of OA but the trend was in decreasing manorand PEG treatment increased (P < 0.004) cellulolytic con-centration (Table 5).