Ram horns obtained from the slaughterhouse of Erzurum, Turkey were hydrolyzed by treating with acid (6N-HCl) and ram horn hydrolysate (RHH) was obtained. The hydrolysate was used as substrate to grow Bacillus cereus NRRL B-3711, Bacillus subtilis NRRL NRS-744 and Escherichia coli in batch system at 30 degrees C; air 1.5 v/v/min; stirring 150 rpm. Both RHH and biomass samples were analyzed. The bacterial cells produced in this hydrolysate were found to be rich in total protein (66%, 68% and 71% for E. coli, B. cereus and B. subtilis, respectively). The chemical oxygen demand and biological oxygen demand were reduced significantly by the growth of bacteria. The protein produced contained all essential amino acids for ruminant feed.