Corn gluten meal is a by-product of the manufacture of maize starch (and sometimes ethanol) by the wet-milling process. Corn gluten meal is a protein-rich feed, containing about 65% crude protein, 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 weedkiller.