Topics:
Animal Nutrition, Animal Refresher
Challenge of Ensiling Legumes
Legumes are difficult to ensiled (the process of silage making) due to:
- High buffering capacity — Correct Answer
- High calcium & phosphorus content
- High protein content
- None
Explanation:
Correct Answer: High buffering capacity
Legumes are difficult to ensile because of their high buffering capacity. Good silage requires rapid acidification (pH drop to <4.5) by lactic acid bacteria. Legumes contain high levels of proteins, amino acids, and organic acids that resist pH change (buffer the rumen) — making it difficult for lactic acid to lower pH quickly enough to preserve the silage.
Comparison: Legumes vs Cereals for Ensiling
| Property | Cereals/Grasses | Legumes |
|---|---|---|
| Buffering capacity | Low ✓ (easy to acidify) | High ✗ (resists acidification) |
| Soluble sugar content | High ✓ (fuel for LAB) | Low ✗ |
| Protein content | Low-moderate | High |
| Moisture at harvest | Variable | High (wilting needed) |
Overcoming Legume Ensiling Difficulty
- Add 3–3.5% molasses to supply fermentable sugars for LAB (lactic acid bacteria).
- Mix with cereals in a 3:1 ratio (grass:legume).
- Wilting before ensiling to reduce moisture and increase sugar concentration.
- Use of acid additives (AIV method) to artificially lower pH.
Why Other Options Are Wrong
- High Ca & P content → minerals contribute to buffering but are not the primary reason for difficulty.
- High protein content → proteins do add to buffering capacity but the broader term "high buffering capacity" is the direct cause.
- None → high buffering capacity is the definitive reason.
