Duroc, breed of pig developed between 1822 and 1877 from the Old Duroc pig of New York and the Red Jersey pig of New Jersey; it was formerly called the Duroc-Jersey. The Duroc proved particularly suitable for feeding in the United States Corn Belt; by the 1930s it was the predominant breed in the United States, a distinction it held intermittently throughout the century. Exportation has been extensive, especially to the temperate regions of North and South America.
Red is the preferred and predominant colour for the Duroc, though wide variations may occur. Breeding selection has emphasized length, trimness, fine muscling, and rapid weight gain.