Ingested feed breakdown produces available energy which is often reduced as heat or used for metabolic processes. 50 to 60% of the total energy in common feed ingredients is available for use by the pig. Digestible energy (DE) is not lost in the feces, while the metabolizable energy (ME) is the amount of DE not lost to gas or urine output. Net energy is the energy retained in the body or the ME without lost heat energy. For formulating energy diets, the net energy system is preferable as it considers the metabolic use of nutrients. This system is being evaluated for use in North America.
The Net Energy System and Diet Formulation Overview (full article)
