BOLINAS, Calif.

WITH some fanfare, the world’s largest pork producer, Smithfield Foods, recently announced that it intended to phase out certain cages for its breeding females. Called gestation crates, the cages virtually immobilize pigs during their pregnancies in metal stalls so narrow they are unable to turn around.

Numerous studies have documented crated sows exhibiting behavior characteristic of humans with severe depression and mental illness. Getting rid of gestation crates (already on their way out in the European Union) is welcome and long overdue, but more action is needed to end inhumane conditions at America’s hog farms.

Of the 60 million pigs in the United States, over 95 percent are continuously confined in metal buildings, including the almost five million sows in crates. In such setups, feed is automatically delivered to animals who are forced to urinate and defecate where they eat and sleep. Their waste festers in large pits a few feet below their hooves. Intense ammonia and hydrogen sulfide fumes from these pits fill pigs’ lungs and sensitive nostrils. No straw is provided to the animals because that would gum up the works (as it would if you tossed straw into your toilet).

In my work as an environmental lawyer, I’ve toured a dozen hog confinement operations and seen hundreds from the outside. My task was to evaluate their polluting potential, which was considerable. But what haunted me was the miserable creatures inside.