Question

A cattle feed was supplied at two levels, i.e 40 and 100 MJ/d. If the additional supply of 60 MJ resulted in an increase in heat production by 24 MJ/d, what will be the heat increment as a proportion of additional energy provided?

• A. 0.2
• B. 0.4
• C. 0.6
• D. 0.8

Hint:

Heat Increment Calculation: $\text{Proportion} = \frac{\Delta \text{Heat}}{\Delta \text{Energy}} = \frac{24}{60} = 0.4$.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Bioenergetics and heat increment of feeding (HIF): calculating the marginal heat increment coefficient from incremental metabolizable energy intake.
Key Formula or Approach:
\[ \text{Heat Increment Proportion} = \frac{\Delta \text{Heat Production}}{\Delta \text{Metabolizable Energy Intake}} = \frac{H_2 - H_1}{\text{ME}_2 - \text{ME}_1} \]

Step 2: Detailed Explanation:
Calculating the heat increment proportion:
1. Incremental energy supplied: \( \Delta \text{Energy} = 100\text{ MJ/d} - 40\text{ MJ/d} = 60\text{ MJ/d} \).
2. Increase in heat production: \( \Delta \text{Heat Production} = 24\text{ MJ/d} \).
3. Proportion of additional energy lost as heat increment (HIF):
\[ \text{Proportion} = \frac{24\text{ MJ/d}}{60\text{ MJ/d}} = 0.40 \]
Thus, $40\%$ of the additional feed energy is dissipated as heat increment.

Step 3: Final Answer:
Therefore, the heat increment proportion is 0.4, matching option (B).