Topics:
Animal Nutrition, Animal Refresher
Formula for Metabolic Body Weight
Metabolic body weight is equals to:
- $W^{0.50}$
- $W^{0.75}$ — Correct Answer
- $W^{2.25}$
- None
Explanation:
Correct Answer: W0.75
Metabolic body weight = W0.75, where W is live body weight in kg. This exponent (0.75) reflects the fact that basal metabolic rate scales non-linearly with body size — larger animals have lower metabolic rate per kg of body weight, but the relationship is not linear (not W1.0).
Metabolic Body Weight Concept
| Parameter | Value/Formula |
|---|---|
| Metabolic body weight | W0.75 |
| Basal metabolic rate (Kleiber's law) | 70 × W0.75 kcal/day |
| Maintenance energy (NRC) | ~77 × W0.75 kcal ME/day |
Why W0.75 and Not W1.0
- A mouse weighing 30 g has a much higher metabolic rate per gram than a 1,000 kg cow.
- The 0.75 exponent was determined empirically by Kleiber (1932) from metabolic measurements across species.
- Using W0.75 allows a single metabolic energy equation to apply across vastly different body sizes.
Why Other Options Are Wrong
- W0.50 → square root of weight; used for surface area estimation, not metabolic weight.
- W2.25 → has no biological basis; 2.25 is the fat-to-carbohydrate energy multiplier.
- None → W0.75 is the universally accepted formula.
📚 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.
