A top animal welfare advocate made an impassioned case in a debate Tuesday for a ballot measure that would mandate the sale of cage-free eggs and more humanely produced pork and veal in Massachusetts, painting a grim picture of sharply confined hens unable to spread their wings and penned-up pigs gnawing on the bars of their cages.

Paul Shapiro, vice president of farm animal protection for the Humane Society of the United States, suggested voters would never allow their pets to be subjected to the kind of confinement now faced by chickens, pigs, and calves.

“These animals are individuals, they have likes, they have dislikes, they have personalities,’’ he said. “And when you force them to live in cages that are so cramped that they can barely move an inch their entire lives, they suffer tremendously. . . . In the same way, if you were to take a dog and put her in a crate where she couldn’t even turn around for her whole life, she’d go insane.’’

Bill Bell of the New England Brown Egg Council, speaking in opposition to the ballot question, suggested the measure was unnecessary, with big restaurant chains and retailers like McDonald’s and Walmart moving toward cage-free eggs — and consumers able to buy them easily in grocery stores.

“If you believe that eggs should be produced in a cage-free environment, you can buy those eggs right now,’’ he said. “This is America and the marketplace responds. But do not vote in support of this referendum question.’’

Bell said Massachusetts residents should not be forced to buy certain products. And he said the increased costs that come with the cage-free mandate would fall hardest on “those least able to afford it.’’

Question 3, one of four ballot measures before voters in November, would forbid the sale of eggs, pork, and veal from animals raised in very tight enclosures. A WBUR poll conducted earlier this month showed voters strongly in favor of the ballot question, with 66 percent in favor and 25 percent opposed.

The debate Tuesday was the second in a series of weekly debates on the ballot questions, sponsored by The Boston Globe, WBUR, and the University of Massachusetts Boston’s McCormack Graduate School of Policy and Global Studies.

Deborah Becker, a WBUR host and reporter, and Joshua Miller, a Globe reporter, moderated the debate, which aired live on WBUR’s “Radio Boston’’ show and streamed live on bostonglobe.com, wbur.org, and umb.edu.

Opponents of the measure have tried to focus on pocketbook issues. All sides agree that the cost of eggs will go up if it passes, though there is considerable debate about how much, with estimates ranging from 12 cents per dozen to 80 cents or more.

Moderators played an audio clip from Diane Sullivan, an advocate for the poor, who talked about her own past struggle to afford food when she was homeless.

“I’ve been in this position more times than I even choose to remember, where I’m forced to make the decision between paying the rent and feeding my children,’’ said Sullivan, who was recruited by a group with ties to agriculture interests in a failed legal challenge to the ballot question.

“I’ve literally gathered change to go to the grocery store to spend a dollar on a dozen eggs. . . . To essentially remove probably the most affordable and accessible form of protein from the diets of those who are already not perhaps eating enough nutritious food, to me doesn’t seem very humane,’’ she said.

Shapiro, of the Humane Society, responded that grocery chains like Stop & Shop and Shaw’s and retailers like Dollar Tree — companies “that could hardly be more cost sensitive’’ — are moving to cage-free eggs.

“If this was really going to unleash the type of economic problems that the agribusiness lobbyists who are opposing Question 3 say, would they really be doing that?’’ he asked. “I don’t think so.’’

Shapiro highlighted what he called hidden costs of confinement, including animal suffering.

But Bell, of the New England Brown Egg Council, said it is not cages that lead to that suffering, but poor management by a handful of bad actors. “The egregious examples of inhumane treatment of animals — that is due to really poor management,’’ he said.

Bell suggested the best approach would be to crack down on those bad actors, rather than mandating the kind of food that can be sold in the state.

David Scharfenberg can be reached at david.scharfenberg@ globe.com. Follow him on Twitter @dscharfGlobe.