Walmart just promised to source only cage-free eggs. Here's what that means.

If you're looking for a sign that more Americans are taking a greater interest in how their food is produced, look no further that what's happening with the humble egg.

It used to be that only people like your activist aunt raged about the cruel conditions in which egg-laying hens are raised. But today an ever-increasing number of Big Food corporations say cage-free is the only kind of egg they'll be willing to buy.

On Tuesday, Walmart — the nation's biggest food seller — promised to go cage-free by 2025. This means the more than 11 billion eggs the company buys each year will come from hens raised in far more humane environs than they currently live in. Last week, PepsiCo promised to transition its North America operations to buying only cage-free eggs by 2020. Supervalu, which has 1,300 discount grocery stores nationwide, said it will be fully cage-free by 2025 too. And these are just the latest in a slew of companies from McDonald's to Panera to Target to reject cages at the farms that supply them.

Where did all this anti-cage momentum come from? Animal rights activists have been snooping around egg barns undercover for years. What they've found is that the millions of hens who lay our eggs live in battery cages — terribly cramped quarters where they can't spread their wings or do anything remotely chicken-like.

With the help of animal scientists who've confirmed that the chickens are indeed miserable in these cages, groups like the Humane Society of the United States have lobbied successfully for changes to laws in several states to require better conditions for hens. Some states have even banned the use of battery cages in egg production entirely. Meanwhile, these laws and the groups' campaigns have helped broaden awareness among consumers.

But despite a growing recognition of the problems in egg production and big commitments to sway the market from the country's largest egg buyers, the hens that lay our eggs are still a long way from being as happy as the one pictured above. And switching a huge company to 100 percent cage-free is way easier said than done. It will take decades and require a massive overhaul of industrial egg-farming practices until you can be sure all your breakfast sandwiches and cookies are made with cage-free eggs.

What are cage-free eggs?

Melanie Stetson Freeman/The Christian Science Monitor via Getty Images

As the words "cage-free" creep onto egg cartons and menus, you might imagine that these birds roam around on green pastures, nibbling grass and laying eggs at their leisure.

But that's not necessarily the case. The government doesn't regulate the label — in fact, the only government-regulated claim made on eggs is "organic." (To call their eggs organic, producers need to follow a standardized set of feeding and growing practices.) The free-range and vegetarian labels on your egg cartons aren't regulated either, and are essentially meaningless.

That said, many of the big retailers are asking companies to comply with United Egg Producers' cage-free standard. But this, too, is voluntary and unregulated. And because cage-free doesn't have a standard definition, it can mean many things.

According to the Humane Society, for example, less then 10 percent of cage-free hens have access to the outdoors, which means most hens are still stuck in the same darkened, industrial barns you may have previously imagined. So the key difference between caged and cage-free birds is that the latter aren't stuck in battery cages the size of iPads that are so restrictive the chickens can't even spread their wings.

As far as animal welfare goes, cage-free is only somewhat superior

In general, cage-free birds have a higher quality of life — they can at least behave more like chickens: walking around the barn and laying their eggs in nests instead of dropping them from their cramped cage into a hole in the ground.

But there are usually a couple thousand birds in one barn, and industrial barns aren't exactly the friendliest places for animals. (They are designed to be lean, mean food-producing machines and not animal sanctuaries.) So that's why some have pointed out that the cage-free system is a marginal improvement.

Paul Shapiro, the vice president of farm animal protection at the Humane Society, has been working on this issue for his entire career. He puts it this way: "Cage-free doesn't mean cruelty free, but it's a substantial improvement." He added: "Our society is moving in the right direction, but it doesn't mean there is not room for continuous improvement." Producers could work harder at improving air quality, outdoor access, and how densely egg-producing hens are stocked in barns, he said.

If you're concerned about how to buy eggs now, the Humane Society had some sound advice: Look for cartons that say Certified Organic or  cage-free. The Humane Society also recommends chains — such as Whole Foods — that have policies against selling battery cage eggs. If your carton doesn't carry these labels, it likely contains caged eggs.

Eggs you order at restaurants may not be more ethical anytime soon

People have been calling 2015 the year of the cage-free egg, since a flock of companies — the likes of Subway, Starbucks, Nestle, and McDonald's, as well as big egg producers such as Rose Acre and Hickman's — all promised to move to 100 percent cage-free eggs.

But right now, according to the USDA, less than 10 percent of hens in the US are cage-free. And the companies' pledges to buy or raise only cage-free eggs mostly take effect five to 15 years from now. (See here for a nice roundup of the companies and their commitments.)

The key reason for the delay: The major egg producers who supply the big buyers need time to transition their practices, and doing so is a lot harder and more expensive than it may seem at first glance. As this excellent Wired article explains, caged systems were designed for maximum egg-making efficiency. And the logistics of a transition to a cage-free system are astoundingly complex.

To begin with, caged birds can't suddenly be freed midway through their lives, so farmers need to wait for a new generation to transition. Traditional caged systems have cost farmers millions to install, and putting in a new cage-free system requires them to pony up millions more. (Chad Gregory, president of industry group United Egg Producers, told Eater that becoming cage-free costs about $40 per bird.) Many producers may wait until the old barns have to be replaced to actually install cage-free systems. And after all that, the cage-free system is just less efficient: It can't hold as many birds, and requires more labor compared with the older battery-cage systems.

There's also the question of what will happen to the price of cage-free eggs. According to Bloomberg News, a dozen cage-free eggs cost twice as much on average: $3.42, compared with about $1.31 or $1.45. Could the price come down as cage-free becomes the norm for the industry? Some estimates from the egg industry suggest that as more producers move to cage-free, prices will rise by a couple of cents per egg.

But it's not clear consumers are really willing to pay more. A study of consumer values by researchers at Oklahoma State University also suggests that people don't necessarily prioritize animal welfare above considerations like safety, taste, and price:

Oklahoma State Dept. of Agricultural Economics

Some economists also wonder whether all the company pledges will ever be realized. Jayson Lusk, an agricultural economist at Oklahoma State University, points to what has happened after some food companies pledged to buy pork only from producers who didn't house pregnant female pigs in gestation crates — narrow stalls that have been denounced as inhumane.

"Companies sometimes had to backtrack when they couldn’t find sufficient supply [of pork] at a price they were willing to pay," said Lusk.

The bottom line: As the years go by, assuming egg farmers can actually make the transition, a greater and greater proportion of eggs sold in this country will be cage-free. But that's a lot of change to hope for, and in the immediate future, most of the eggs you're eating will still come from caged hens.

There’s also a long road ahead in improving the welfare of other animals raised for food. Take broiler chickens: They suffer all kinds of health problems because they're bred to grow fast and put on lots of meat. But slowly animal welfare is making its way into how we want our food to be produced.

Clarification: A previous version of this article stated that the Humane Society ​of the US recommends Animal Humane Certified as a source of cage-free eggs, based on ​information on the ​HSUS​ site that is now out of date. ​The HSUS says it does not recommend American Humane Certified since it allows cage confinement.

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