Metabolizable energy is used to estimate what in diet formulation?

• A. The net energy available for maintenance and production after losses.
• B. The total gross energy of the feed.
• C. The digestible energy only.
• D. The energy lost as heat.

Answer: (A)

Metabolizable energy represents the energy that remains after the animal has excreted feces, urine, and gaseous products from the feed’s gross energy. In diet formulation, this is used as an estimate of the energy actually available for the animal to use for maintenance and production. It’s more indicative of usable energy than gross energy, which includes energy that can’t be utilized, and more complete than digestible energy, which misses urine and gas losses. The energy lost as heat is accounted for later when moving from metabolizable energy to net energy, which is the portion available for maintenance and production.