Massachusetts voters on Tuesday passed a landmark law to protect farm animals from intensive confinement.

The initiative will eventually prohibit farming methods that keep animals /ballotpedia.org/Massachusetts_Minimum_Size_Requirements_for_Farm_Animal_Containment,_Question_3_(2016)"}}">severely constrained for virtually their entire lives, including the use of veal crates for baby calves, gestation crates for mother pigs and battery cages for egg-laying hens.

Eleven states have passed /www.humanesociety.org/issues/confinement_farm/timelines/timeline_farm_animal_protection.html"}}">bans on one or more of those practices. The Massachusetts measure will /www.citizensforfarmanimals.com/"}}">outlaw all three, and then go further. It will also bar the sale of meat and eggs produced using those methods, even from animals that were farmed outside the state.

Public polls consistently showed the measure receiving strong support, and while several agribusiness groups opposed the initiative, they spent little to campaign against it.

Farms and businesses have until 2022 to comply with the new requirements.

Mercy for Animals Mother pigs will often spend most of their lives in gestation crates, unable to turn around or lie down naturally, let alone practice typical social behaviors. The crates allow large industrial farms to make efficient use of space and streamline feeding.

California is the only state that currently bans the sale of food products over animal cruelty concerns, and its law applies only to eggs from caged hens.

The Massachusetts law, which includes veal and pork, is the broadest of its kind in the U.S. and probably the world, according to Paul Shapiro, head of the farm animal welfare campaign at the Humane Society of the United States, which spearheaded the ballot drive.

That law applies exclusively to the moment when livestock are slaughtered; it says nothing about how farm animals should be treated during the rest of their lives, from birth onward. It also completely exempts chickens and other animals that make up well over 90 percent of the animals slaughtered.

Thus, it is perfectly legal for female pigs, among the most cognitively complex and socially sophisticated animals, to be repeatedly impregnated and held in small crates for months on end, unable to respond to their most basic instincts.

Likewise, each year, hundreds of millions of egg-laying hens spend their lives inside wire cages so small they cannot flap their wings. Peter Singer, a professor of bioethics at Princeton University, refers to caged hens as “the most closely confined, overcrowded and generally miserable animals in America.”

But these corporate reforms are entirely voluntary. Measures like the one in Massachusetts are needed to cement those changes, Shapiro said.