Animal welfare groups have recognized Smithfield Foods’ progress in transitioning to a less-stressful way of housing breeding hogs but also called for the nation’s largest pork producer to move faster.

Smithfield Foods has announced that at the end of 2012, 38 percent of pregnant sows on company-owned farms in America had been moved from individual gestation stalls to group housing systems.

Animal welfare groups had been highly critical of the company’s use of gestational housing, which they say confines breeding pigs in “crates” for 24 hours a day during their four-month pregnancy.

“The Humane Society of the United States welcomes Smithfield’s announcement that it is phasing out its use of gestation crates,” Humane Society President and CEO Wayne Pacelle stated in a news release.

“Nearly half of sows on Smithfield’s company-owned facilities worldwide — and nearly 40 percent in the United States — are now housed in groups instead of crates, and that shows that this transition away from crate confinement is economically viable.”

In a telephone interview, Dave Byer, senior corporate liaison for People for the Ethical Treatment of Animals, said, “Moving away from gestation crating eliminates one of the worst practices on pig farms.” But Smithfield is “moving too slowly” in completing the transition, he said.

Smithfield says it is on track to entirely complete the conversion to group housing on company-owned U.S. farms by 2017.

The decision to convert to group housing for pregnant sows on all company-owned U.S.

farms was made in 2007 based on customer input, according to a news release.

Company hog production operations overseas are also changing to group housing, with that transition set for completion by 2022. Conversions are already complete in Poland and Romania, the company reports.

“We’re proud of the commitments made by our international operations, and here in the U.S. we are continuing to make good progress toward our goal of phasing out gestation stalls for pregnant sows at all of our company-owned farms, as our 2012 conversion number reflects,” said C. Larry Pope, president and chief executive officer of Smithfield Foods.

Both the Humane Society and PETA also urged the company to require its contract pig breeders to also stop using gestation stalls. Until it does, “pigs will remain kept in their own excrement,” Byer said.

ConAgra, another large American pork producer, also announced late last year that it would eliminate the practice.

Oscar Mayer, McDonald’s, Burger King, Wendy’s, Costco, Safeway, Kroger are among other top food companies that have made similar announcements against gestation stalls.