The American Yorkshire, a breed of domestic pig, is the American version of the Large White pig, white in color, with erect ears, which are different from the lop ears of the chester white.The average litter size is 13 piglets per sow. American Yorkshires are the most recorded swine breed in the United States.
The Yorkshire breed was developed in Yorkshire, England, circa 1761. In 1830, the first Yorkshires were imported to the United States, specifically to Ohio, but because of their slow growth rate, they did not become popular until the late 1940s. At that time, many large Yorkshires were imported from Canada and England for their ruggedness and favored carcasses. The breed then improved rapidly through selection.
Today, Yorkshire pigs are found in nearly every American state, with highest populations in Illinois, Indiana, Iowa, Nebraska, and Ohio. The modern Yorkshire is muscular with a high proportion of lean meat. Yorkshire data have been maintained with great diligence, including growth, sow productivity, and backfat formation, representing the largest source of documented livestock performance records in the world.