Microorganism that Controls Rumen Microbial Population

Correct Answer: Protozoa

Protozoa control the rumen microbial population by predating on bacteria (primary population regulators). Despite bacteria multiplying rapidly, protozoa keep their numbers in check.

Mechanism

• Protozoa engulf and digest bacterial cells
• In defaunated rumen (protozoa removed): bacterial count increases significantly
• Improved microbial protein flow to duodenum in defaunated animals

Bacteriophage also lyse bacteria but are secondary controllers; protozoa are the primary regulators.