Topics:
Animal Nutrition, Animal Refresher
Nutritional Definition of Roughage
Roughage contains:
- CF > 18% & TDN < 60% — Correct Answer
- CP > 20% & CF >18%
- CF > 18% & TDN > 60%
- CF < 18% & TDN > 60%
Explanation:
Correct Answer: CF > 18% & TDN < 60%
Roughage is defined by having high crude fibre content (>18%) and low energy content (TDN <60%). These two criteria together distinguish roughage from concentrate feeds.
Roughage vs. Concentrate — Classification Criteria
| Feature | Roughage | Concentrate |
|---|---|---|
| Crude Fibre (CF) | >18% | <18% |
| TDN | <60% | >60% |
| Energy content | Low | High |
| Digestibility | Low | High |
| Bulk/density | High bulk, low density | Low bulk, high density |
| Main function | Belly-filling | Energy supply |
Examples of Roughage
- Dry roughage: Straw, stover, hay
- Succulent roughage: Silage, tree leaves, pasture, green fodder
Why Other Options Are Wrong
- CP > 20% & CF >18% → describes protein supplement + roughage mix; not the standard roughage definition
- CF > 18% & TDN > 60% → contradictory; high fibre feeds cannot have high TDN (fibre reduces energy availability)
- CF < 18% & TDN > 60% → this is the definition of concentrate, not roughage
📚 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.
