Topics:
Animal Physiology, Animal Refresher
Normal pH of Rumen
Normal pH of rumen is:
- 6.5–6.8 — Correct Answer
- 6.2–7.2
- 5–6
- 4–5
Explanation:
Correct Answer: 6.5–6.8
The normal pH of rumen liquor is 6.5 to 6.8 (slightly acidic). This weakly acidic environment is essential for normal rumen microbial activity and fermentation.
pH and Rumen Microbiology
- The major microorganisms in rumen (bacteria, protozoa, fungi) thrive optimally at pH 6.5–6.8.
- pH is maintained by the buffering action of salivary bicarbonate and phosphate — cattle produce 100–150 litres of saliva/day, rich in NaHCO₃.
- VFAs (Volatile Fatty Acids — acetate, propionate, butyrate) produced by fermentation would normally drop pH, but saliva continuously neutralizes them.
Abnormal pH Changes
- High grain diet → excess lactic acid production → pH drops below 5.5 → ruminal acidosis (grain engorgement/grain overload). At very severe engorgement, pH can drop to 4.
- Excess protein diet → ammonia accumulation → pH rises above 7 → ruminal alkalosis.
pH of Various GIT Compartments
- Saliva of ruminants: 8.0 (alkaline)
- Rumen: 6.5–6.8
- Abomasum: 2.0 (strongly acidic)
- Blood: 7.4
📚 About this Topic — Animal Physiology
This multiple choice question is from Animal Physiology, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Physiology to strengthen your preparation.
