Corn gluten is a by-product of the manufacture of maize starch (and sometimes ethanol) by the wet-milling process. Corn gluten is a protein-rich feed, containing about 65% crude protein (DM), used as a source of protein, energy, and pigments for livestock species including fish. It is also valued in pet food for its high protein digestibility. In the USA and Canada, corn gluten meal is also used as a fertilizer and pre-emergent weed killer.
Corn gluten is obtained wherever maize is used for starch extraction. It is distributed worldwide. Its production has become relatively constant since ethanol is now mainly produced by dry-milling, which yields corn distillers rather than corn gluten meal and corn gluten feed. Corn gluten can be fed wet or dried, but dried is more common.