Massachusetts voters Tuesday passed a groundbreaking ballot question that will mandate all pork, veal, and eggs farmed and sold in Massachusetts come from pigs, calves, and laying hens not confined to ultratight quarters.
While voters in other states have banned certain farming practices through referenda, no ballot measure has outlawed the sale of products from animals raised in a particular way. That means the result of Question 3 will affect farms around the country, and grocery stores from Pittsfield to Provincetown.
The animal welfare initiative, which will take effect in 2022, was leading 78 percent to 22 percent with 58 percent of precincts reporting just after 11 p.m.
“It’s a historic advancement for animal welfare,” said Paul Shapiro, vice president of policy at the Humane Society of the United States, the main backer of the measure.
“To have an entire state declare that cruelty to farm animals is such a pressing matter that it is establishing a retail standard to ensure that animals are able to at least engage in basic movement really sends a powerful signal,” he said.
Opponents — the agricultural industry and some advocates for low-income people — say the measure is certain to spike prices on key food staples.
In particular, they point to the mandate that all eggs sold in Massachusetts be from cage-free hens, saying that will raise the cost of a key source of protein and, effectively, create a regressive tax with an outsize impact on poor families.
In one of the TV ads against the measure, Diane Sullivan, a Medford mother who managed the opposition campaign and has struggled with poverty herself, called the initiative “a new food tax our low-income and working poor neighbors can least afford.”
But polling showed voters were predisposed to vote for the measure, and proponents outspent opponents by millions of dollars, according to state campaign finance filings.
Advocates, including the Massachusetts Society for the Prevention of Cruelty to Animals, say the current conditions are unspeakably savage, with many hens housed in cages in which each bird has less space than an 8½-by-11-inch piece of paper, and pregnant sows trapped in spaces so tight they are unable to move. The referendum, they argue, is just a modest measure to ensure animals can stand up, turn around, and spread their limbs.
But the farm industry says current practices are humane, safe, and the most efficient way for consumers to have access to low-cost food.
Estimates of how much egg prices could change range from about 12 cents more per dozen to nearly $1 more per dozen.
But there’s no way to know how much prices will go up until it goes into effect. Starting in 2022, the law will mandate all Massachusetts farms and businesses produce and sell eggs only from cage-free hens; pork from pigs not raised in or born of a sow raised in a small crate; and veal from calves not raised in very tight enclosures.
Because Massachusetts is not a farming-heavy state, even opponents of the measure say the impact on farms here will be minimal. But they have a deeper worry.
Organizations like the National Pork Producers Council allege the end goal of the measure — and the Humane Society — is to raise the price and reduce the consumption of meat, as part of a “vegan agenda.”
Officials with the Humane Society deny that charge and say their goal is to simply make sure animals aren’t treated so cruelly.
Sullivan, the top opponent of Question 3, hinted that Tuesday’s result might not be the final word on the matter. She said the referendum “opened my eyes to this food policy debate” and “my work on this has just begun.”
Opponents are likely to eventually file a federal lawsuit over the new law, according to one person familiar with their strategy. They are expected to allege that the voter-approved measure — which will ban the sale in Massachusetts of certain products from other states — infringes on constitutionally protected interstate commerce.
The Humane Society says several federal courts have ruled on similar animal protection measures and have found them to be wholly consistent with the Constitution.
Joshua Miller can be reached at firstname.lastname@example.org. Follow him on Twitter @jm_bos and subscribe to his weekday e-mail update on politics at bostonglobe.com/politicalhappyhour.