Which pair of energy components make up net energy (NE) in animal feeds?

• A. NEm and NEp
• B. Digestible energy and metabolizable energy
• C. Gross energy and net energy
• D. NEp and Gross energy

Answer: (A)

Net energy is the portion of feed energy available to an animal after all losses, and it is split into two parts: energy needed for maintenance and energy available for production. The maintenance portion covers basic body functions and daily upkeep, while the production portion supports growth, milk production, or other productive activities. Adding these two parts gives the total energy the animal can use, so the correct pairing is maintenance energy and production energy.

Digestible energy and metabolizable energy are earlier stages in the energy flow and do not directly sum to net energy. Gross energy is the total energy in the feed, not the usable portion after losses, and pairing it with net energy also doesn’t reflect how NE is partitioned.