Topics:
Animal Nutrition, Animal Refresher
Thresholds for Urea Toxicity
Urea toxicity results in cattle when:
- Rumen $NH_{3}$ level exceeds $80mg/dl$
- $NH_{3}$ concentration in blood exceeds $1~mg/dl$
- Both are correct — Correct Answer
- None
Explanation:
Correct Answer: Both are correct
Urea toxicity in cattle occurs when either: (1) rumen NH₃ exceeds 80 mg/100 ml, OR (2) blood NH₃ exceeds 1 mg/100 ml. Both thresholds are diagnostically valid.
Urea Toxicity Thresholds
| Parameter | Toxic Level | Normal/Optimum Level |
|---|---|---|
| Rumen NH₃ | >80 mg/100 ml | 5–8 mg/100 ml (optimum) |
| Blood NH₃ | >1 mg/100 ml | Trace amounts |
Treatment of Urea Toxicity in Cattle
- Drenching 20–40 litres of cold water (cold water inhibits ureolytic activity)
- Drenching 4–5 litres of 10% acetic acid (neutralises released NH₃)
Urea Characteristics
- Nitrogen content: 46.6% (pure form)
- 100% rumen-degradable
- No energy value; deficient in all minerals
- Adaptation period for rumen microbes: 2–4 weeks
Why Other Options Are Wrong
- Rumen NH₃ >80 mg/dl alone → correct but incomplete; blood NH₃ level is equally valid
- Blood NH₃ >1 mg/dl alone → correct but incomplete; rumen threshold also applies
- None → incorrect; both thresholds are established diagnostic criteria
📚 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.
