Question

Acute rumen indigestion occurs due to accumulation of –

• A. d-Lactate
• B. l-Lactate
• C. Both d and l-Lactate
• D. Ammonia gas

Hint:

Remember that the microbial fermentation of grain in the rumen produces both stereoisomers of lactic acid (D and L).
Their joint accumulation is the direct biochemical cause of acute rumen acidosis.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Acute rumen indigestion (rumen acidosis or grain overload) is a metabolic disease in ruminants caused by the rapid ingestion of highly fermentable carbohydrates.

Step 2: Detailed Explanation:
1. Rapid consumption of starch-rich grains alters the microbial population in the rumen, promoting the overgrowth of amylolytic bacteria like *Streptococcus bovis* and *Lactobacillus* species.
2. These bacteria ferment carbohydrates rapidly, producing large quantities of both D-lactate and L-lactate isomers.
3. Since the rumen cannot metabolize D-lactate quickly, both isomers accumulate, dropping the rumen pH below \(5.0\).
4. This accumulation destroys normal cellulolytic microflora, damages the rumen epithelium, and causes systemic lactic acidosis.

Step 3: Final Answer:
The correct option is 3, which corresponds to Both d and l-Lactate.