Characteristics of Ruminal Bacteria

Correct Answer: All the above

All three statements are correct:

• (a): Most rumen bacteria are gram-negative obligate anaerobes. Exception: lactic acid bacteria are facultative anaerobes attached near the rumen wall.
• (b): Bacteria population is 10¹⁰⁻¹¹ per ml — the most numerous of all rumen microbes.
• (c): Optimum temperature for rumen microbial activity is 39°C (rumen body temperature). Normal rumen pH = 6.5–6.8.

Rumen Microbial Population

• Bacteria: 10¹⁰⁻¹¹/ml
• Bacteriophage: 10⁹/ml
• Protozoa: 10⁶/ml
• Fungi/Yeast: 10³/ml