The Pork Industry in the United States

Commercially bred pigs are prolific; they mature quickly and are capable of having numerous young. After a gestation period of four months, a sow gives birth to an average of ten piglets, though the litter can be as large as thirty. These piglets can increase in weight by 5,000 percent in a six-month period.

In the United States, pigs are classified as lard, meat, or bacon hogs. Lard is the rendered fat tissue of pork. While crossbred pigs or hybrid pigs make up 80 percent of the commercial pork market, out of about three hundred different breeds, the eight most commonly used by pork producers in the United States are Berkshire, a black-haired pig renowned for its flavor and meatiness; Chester White, a white pig that originated in Pennsylvania; the fast-growing, mahogany-colored Duroc; the lean, muscular Yorkshire; Hampshire, a black pig with erect ears and a thick white band around its middle and its front legs; Landrace, a white pig descended from Danish stock; Poland China, a black-bodied pig, its nose and all four legs dipped in white; and Spotted Swine, a breed characterized by black and white spots.