Topics:
Animal Nutrition, Animal Refresher
Quality Indicators of Very Good Silage
In very good silage the pH and ammoniacal nitrogen concentration ranges between:
- pH = 3.5-4.2, Ammoniacal $N_{2}$ is less than 10% — Correct Answer
- pH = 4.2-4.5, Ammoniacal $N_{2}$ = 10-15%
- pH = Above 4.8, Ammoniacal $N_{2}$ = 20%
- None
Explanation:
Correct Answer: pH = 3.5–4.2, Ammoniacal N₂ < 10%
Very good silage is characterised by a low pH (3.5–4.2) indicating dominant lactic acid fermentation, and very low ammoniacal nitrogen (<10% of total N) indicating minimal protein degradation.
Silage Quality Classification
| Quality Grade | pH | Ammoniacal N₂ (% of total N₂) | Butyric Acid |
|---|---|---|---|
| Very Good | 3.5–4.2 | <10% | Nil |
| Good | 4.2–4.5 | 10–15% | Trace |
| Fair | ≥4.8 | ≥20% | Some amount |
Silage Quality Notes
- Colour of good silage: Yellowish or Brownish-green
- Best crop for silage: Maize (Zea mays)
- Lactic acid fermentation (good silage) → occurs when fodder is rich in soluble carbohydrates
- Butyric acid fermentation (bad silage) → occurs when fodder is rich in proteins
- Flieg Index is the commonly used method for silage quality evaluation
Why Other Options Are Wrong
- pH 4.2–4.5, NH₃-N 10–15% → these are characteristics of "Good" silage, not "Very Good"
- pH above 4.8, NH₃-N 20% → these indicate "Fair" (poor quality) silage
- None → incorrect; 3.5–4.2 with <10% NH₃-N is the established standard
📚 About this Topic — Animal Nutrition
This multiple choice question is from Animal Nutrition, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Nutrition to strengthen your preparation.
