Topics:
Animal Nutrition, Animal Refresher
Determinant of Metabolic Faecal Nitrogen
Metabolic faecal nitrogen (MFN) depends upon:
- Dry matter intake (DMI) — Correct Answer
- Protein content of feed
- Energy content of feed
- None
Explanation:
Correct Answer: Dry Matter Intake (DMI)
Metabolic Faecal Nitrogen (MFN) represents the endogenous nitrogen losses in faeces that are independent of dietary protein — they come from intestinal cell debris, digestive enzymes, and mucus. MFN is directly proportional to Dry Matter Intake (DMI), not dietary protein content.
Types of Faecal Nitrogen
| Type | Source | Depends On |
|---|---|---|
| Dietary faecal N | Undigested feed protein | Dietary protein level |
| Metabolic faecal N (MFN) | Intestinal cells, enzymes, mucus | Dry Matter Intake (DMI) |
Significance of MFN
- MFN must be subtracted from total faecal N to calculate true digestibility of protein.
- True protein digestibility = apparent digestibility + MFN correction.
- MFN is approximately 2–3 g/kg DMI in most species.
Why Other Options Are Wrong
- Protein content of feed → influences dietary faecal N, not metabolic faecal N.
- Energy content of feed → indirectly affects DMI but does not directly determine MFN.
- None → DMI is the correct determinant.
📚 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.
