Topics:
Animal Nutrition, Animal Refresher
Collection in Metabolic Trials
In metabolic trial, which is/are used & collected for estimation:
- Urine
- Faeces
- Both — Correct Answer
- None
Explanation:
Correct Answer: Both (Faeces and Urine)
In a metabolic trial, both faeces and urine are collected. This allows measurement of the complete nitrogen balance (intake − faecal N − urinary N = retained N) and energy balance of the animal.
Trial Types and Collections
| Trial Type | Collection | Purpose |
|---|---|---|
| Digestibility trial | Faeces only | Apparent digestibility of nutrients |
| Metabolic trial | Faeces + Urine (Both) | Nitrogen balance, energy balance, true biological value |
Why Both Are Needed in Metabolic Trial
- Faeces → unabsorbed nutrients + endogenous secretions
- Urine → absorbed-but-not-retained nutrients (e.g., urea from protein catabolism)
- Only by measuring both can true retention be calculated: Retention = Intake − Faecal loss − Urinary loss
Application — Biological Value (BV) of Protein
- BV = (N intake − faecal N − urinary N) / (N intake − faecal N) × 100
- BV requires both faecal and urinary nitrogen → metabolic trial, not digestibility trial
Why Other Options Are Wrong
- Urine alone → incomplete; faeces also needed to account for unabsorbed nutrients
- Faeces alone → this is the digestibility trial, not metabolic trial
- None → incorrect; both faeces and urine are collected in metabolic trials
📚 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.
