Topics:
Animal Nutrition, Animal Refresher
Protein Equivalents of NPNs
Protein equivalent of urea and biuret are respectively:
- 281, 219 — Correct Answer
- 219, 281
- 225, 300
- 300, 225
Explanation:
Correct Answer: Urea = 281, Biuret = 219
Protein Equivalent of Urea = 281% and Biuret = 219%. These values are calculated as: N% × 6.25. Urea N% ≈ 46.6% → 46.6 × 6.25 ≈ 291% (textbook commonly cited as 281%). Biuret N% ≈ 35% → 35 × 6.25 ≈ 219%.
Protein Equivalent of Common NPN Sources
| NPN Source | N% | Protein Equivalent (%) |
|---|---|---|
| Urea [CO(NH₂)₂] | ~46.6% | ~281–291% |
| Biuret | ~35% | ~219% |
| DAP (Diammonium Phosphate) | ~18% | ~112% |
| Ammonium Sulfate | ~21% | ~131% |
Significance of High Protein Equivalent
- 1 kg urea replaces approximately 2.8 kg crude protein from conventional sources — making it highly cost-effective for ruminants.
- Urea must always be paired with readily fermentable energy (starch) at 10:1 starch:urea ratio.
- Biuret is safer than urea (slower rumen degradation) but has lower protein equivalent.
Why Other Options Are Wrong
- 219, 281 → reverses the correct order; urea has higher PE than biuret.
- 225, 300 → approximate but incorrect values for these NPN sources.
- 300, 225 → also reversed and incorrect.
📚 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.
