Topics:
Animal Nutrition, Animal Refresher
External Indicators for Digestibility
Example(s) of external indicator in digestibility estimation:
- Chromic oxide
- Carmine red dye
- Magnesium ferrite
- All the above — Correct Answer
Explanation:
Correct Answer: All the above
Chromic oxide, Carmine red dye, and Magnesium ferrite are all examples of external indicators used in digestibility estimation.
External Indicators — Complete List
| External Indicator | Notes |
|---|---|
| Chromic oxide (Cr₂O₃) | Most widely used external indicator |
| Ferric oxide (Fe₂O₃) | Iron-based inert marker |
| Magnesium ferrite | Magnetic marker; easy to detect in faeces |
| Carmine red dye | Visual marker for start/end of collection period |
| Radioisotopes (Cr-EDTA, Cerium) | Liquid phase and solid phase markers respectively |
| Cobalt-EDTA, PEG | Liquid phase markers |
Liquid Phase Markers
- Polyethylene glycol (PEG), Cobalt-EDTA, Chromium-EDTA
Why Other Options Are Wrong
- Chromic oxide alone → external indicator but incomplete
- Carmine red alone → external indicator but incomplete
- Magnesium ferrite alone → external indicator but incomplete; all three are correct examples
📚 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.