Endogenous protein
Definition
A certain amount of protein is always lost during the digestion process: this is called endogenous protein. Endogenous protein comes from the animal and consists of digestive enzymes, bile, intestinal mucus and dead intestinal epithelial cells. It is excreted in manure.
Importance
Although endogenous protein originates from the animal itself, its loss is largely influenced by the ration. Lower digestibility in the feed leads to greater endogenous protein loss. The current intestinal digestible protein system (2007) accounts for this through the fraction known as intestinal digestible metabolic fecal protein (MFP).
