The science of breeding, raising, and marketing swine. This agricultural enterprise is usually located in proximity to sources of high-energy feedstuffs; in the United States, the geographical distribution of swine production is closely related to maize and sorghum production. Swine, as nonruminants, utilize large quantities of concentrate feeds; it is estimated that 30% of the maize grain produced is fed to swine. Swine can utilize only limited quantities of roughage in their diet.