Question

In energy partitioning, the net energy content of a feed is calculated by subtraction of which among the followings from the metabolizable energy content of that feed

• A. Heat increment
• B. Urinary energy
• C. Gaseous energy
• D. Fecal energy

Hint:

Remember the sequential energy losses:
GE \(\rightarrow\) lose Feces \(\rightarrow\) DE \(\rightarrow\) lose Urine/Gas \(\rightarrow\) ME \(\rightarrow\) lose Heat \(\rightarrow\) NE.
This simple sequence makes it easy to remember any energy partitioning equation.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Energy partitioning describes how the total gross energy of a feed is digested, metabolized, and utilized by an animal.
At each step of digestion and metabolism, energy is lost from the system in different forms, leaving a smaller portion of net energy available for maintenance and production.

Step 2: Detailed Explanation:
Let us review the steps of energy partitioning in animals:
1.Gross Energy (GE): The total potential energy in the feed.
2.Digestible Energy (DE): Calculated by subtracting fecal energy losses (D) from the gross energy:
\[ DE = GE - \text{Fecal Energy} \] 3.Metabolizable Energy (ME): Calculated by subtracting urinary energy losses (B) and gaseous energy losses (C) from digestible energy:
\[ ME = DE - (\text{Urinary Energy} + \text{Gaseous Energy}) \] 4.Net Energy (NE): This is the actual energy available to the animal for maintenance and production.
It is calculated by subtracting the heat increment (HI) from the metabolizable energy:
\[ NE = ME - \text{Heat Increment} \] The heat increment is the heat produced during the physical and chemical processes of digesting and metabolizing nutrients, which is dissipated as waste heat.

Step 3: Final Answer:
The net energy content of a feed is calculated by subtracting the Heat increment from the metabolizable energy.