Why Yorkshires Are Considered the Mother Breed of the U.S. Swine Industry

For nearly 70 years, the Yorkshire pig has been known as “the mother breed” — and for good reason.

“What they are known for is their mothering ability,” said Richard Coffey, the head of Oklahoma State University’s Department of Animal and Food Sciences.

But they’re becoming known for so much more.

Yorkshires have large litter sizes, produce a lot of milk and are attentive to their piglets. This mothering ability has made them the go-to sow line in the U.S. swine industry.

Yorkshires are often used as either the grandparent line or parent line in commercial pigs across the nation.

For the grandparent line, a Yorkshire sow is crossed with a Landrace boar to produce an F1 progeny. Sows from this line are often crossed with Durocs to be raised for market.

Purebred Yorkshire sows are also used as parents, again typically crossed with a Duroc or a Hampshire.

“Because (Yorkshires are) one of the foundations for our grandparent lines, it’s easy to see that that would be one of the largest breeds — if not the largest breed — in our industry today,” said Chris Hostetler, the National Pork Board’s director of animal science.

The first documented Yorkshires in the U.S. came to Ohio around 1830. The breed rapidly expanded in the 1940s and was recognized for its maternal instincts in the late 1950s.

At one point, there were about 500,000 registered purebred Yorkshires in the U.S.

However, the introduction of indoor commercial swine facilities came with a decrease in purebred Yorkshire numbers, as producers began crossbreeding to fit the new production method’s demands.

“Over the years, the purebreds have decreased in prevalence in the U.S.,” Hostetler said. “Having said that, we still use those purebred lines at either the grandparent level or the parent level that would ultimately generate our commercial pigs.”