Are cage-free chickens happier? Unfortunately, we can’t ask them. (Mike Blake/Reuters)

What makes a chicken happy?

Happiness is hard to measure, which makes it easy to ignore.

Our animal agriculture has become progressively more efficient; livestock grows faster on less feed. To accomplish that, most animals have been taken indoors, kept in progressively smaller spaces for their progressively shorter lives.

But are they unhappy?

A lot of people are asking the question, and animal welfare concerns are beginning to get traction, particularly when it comes to chickens. Several recent announcements are grounds for optimism that animals’ well-being will start playing a bigger role in how large companies raise the ones that give us meat, milk and eggs.

United Egg Producers, a trade association whose members own 95 percent of our country’s egg-laying hens, has announced an agreement to end the culling of male chicks by 2020. “Culling” is killing, and our current system sends male chicks, useless in the egg business, to a grisly death, either by grinding or gassing.

The grinding is the grisliest. The pictures of hours-old (cute, fluffy) chicks being tossed into high-speed grinders are stomach-churning. We could argue over whether that procedure is consistent with animal welfare — after all, it is a near-instant death — but now we won’t have to. Even those who defend the practice have to be happier with the system that’s replacing it: determining an embryo’s gender while it’s still in the egg, and using the male eggs for something else (pet food, for example).

That is a clear win. For animals, but also for the industry, which now has eggs it can use for constructive purposes, rather than those useless male chicks. And I think we all win when no worker has the grim and heart-hardening job of throwing baby chicks into a grinder.

Not everyone agrees on another trend in the egg world: going cage-free.

Everybody’s doing it! Supermarkets (and not just Whole Foods, but also Costco, Albertsons, Kroger, Walmart and others). Restaurants (including McDonald’s, IHOP, Applebee’s, Taco Bell). Manufacturers (Unilever, Hershey’s, Nestle, ConAgra). Also food-service companies, hotels and resorts. The timelines differ, but there’s no question that demand for cage-free chickens will change industry practices.

Scientists who study the impact of different production practices almost inevitably conclude that each system has advantages and disadvantages. Yes, chickens can “perform a greater repertoire of behaviors” in a cage-free system, one recent evaluation concludes, but it warns that those behaviors include cannibalism. Taking animals out of cages and giving them litter to scratch around in also provides a “greater opportunity for disease and parasites” and increases the number of bone fractures.

And what of the downside of confinement? Is being caged stressful? Painful? We don’t really know. Of stress, the evaluation says that “less is understood.” And we don’t always know when people are in pain, so how are we supposed to figure out whether a chicken’s hurting?

It’s hard to make the liberty-vs.-security calculation when the costs of liberty (injury, mortality, predation, disease) are measurable but the benefits (well-being, happiness, freedom from pain) often aren’t. But I don’t think the list of potential harms of going cage-free can justify keeping a bird in a cage so small she can’t spread her wings, and I’m very glad to see the balance shifting.

A similar cost-benefit analysis is happening in the organic world, where new animal-welfare rules are being considered. One of the requirements for chickens — both egg layers and meat birds — would be outdoor access. And quite a bit of it. Regulations proposed by the U.S. Department of Agriculture call for a maximum of 2.25 pounds of bird per square foot of outdoor space for egg layers, and a 5-pound maximum for meat birds. (A typical laying hen weighs about five pounds, and a meat bird grows from hatching to six or seven pounds in six or seven weeks.)

Many U.S. stores, food producers and restaurants have started using or selling eggs only from cage-free hens. (Julia Ewan/The Washington Post)

According to Nate Lewis, senior crops and livestock specialist with the Organic Trade Association, predators and pathogens are the “main concern” of the organic producers who are pushing back against the new regulations. He calls those threats real, but he points out that most farms are good at keeping predators out, and that all the flocks that got avian flu last year were confined indoors. Those who favor the new regulations (and Lewis’s group does) say that allowing chickens to express natural behaviors — scratching in soil, tracking down insects, dust-bathing in the sun — trumps concerns about disease or predators.

Science can’t adjudicate this dispute yet. Although science isn’t silent on well-being, and animal scientists can measure cortisol (an indication of stress) and play behavior (an indication of relaxation), some of the issues surrounding conditions in confined animal operations defy scientific rigor.

My husband and I have watched the liberty-vs.-security trade-off play out in our back yard. We’ve raised chickens for some six years, and I’m ready to say that they’re happier when they have plenty of room, access to sunlight and ground to scratch up. I arrived at that opinion in the same way you figured out what makes your cat, or your dog, or your parakeet happy. Animals — even chickens — have plenty of ways of telling us what they like and don’t like.

They like it when you bring them melon seeds. Also corncobs. They don’t like strange noises, or when another chicken is in the nest box they want. (They always seem to squabble over the same one, even when several are empty.) And they like to go outside. They pace back and forth next to the door when they see you coming. As soon as the door opens, they bolt.

We live on two wooded acres and, until recently, we let our chickens have the run of the place during the day. At night, they went home to their predator-proof (so far) run, and we locked them away from our local carnivores: raccoons, coyotes and other nocturnal hunters. In the morning, we opened the door and let them range free. Liberty!

We got a firsthand lesson in the perils of outdoor access when a fox (a daytime hunter, which we’d never had before) moved into our neighborhood and snatched half of our flock in one afternoon. Now, our birds stay in their run, which has sunshine and deep litter and things to climb and perch on, as well as plenty of elbow room, but no outdoor access. The fox tipped the balance to security.

You can’t extrapolate from a backyard flock to a commercial one — if you’re raising tens of thousands of birds, you don’t bring them cantaloupe innards — but some of the fundamental questions are the same. Does increased risk of disease or predators mean that we should keep birds indoors? Are chickens that don’t go outside, chickens that don’t even have a concept of “outside,” unhappy? And if they are less happy, are we willing to sacrifice some well-being to provide inexpensive eggs and meat for people?

These are some of the questions being debated as consumer pressure increasingly shines a light on the practices of industrial animal farming. And Perdue Farms is stepping up. The company has been in the vanguard of changing conventional practices since it became the first big producer to start phasing out antibiotics (less an issue of animal welfare than of human health, since using antibiotics in livestock contributes to antibiotic-resistant bacteria) back in 2002.

Perdue has started installing windows and environmental enrichments in chicken houses and is focused on increasing bird activity. (Exercise benefits chickens, as it does humans.) Perdue Senior Vice President Bruce Stewart-Brown told me that “it’s appropriate to start paying attention to what chickens want.” About 10 percent of Perdue birds have outdoor access, and that “has allowed us and me to get a better perspective on what it adds and what the challenges are,” he said. “Not every area is appropriate for outdoor access. There are climates where it’s way more comfortable in the chicken house. When you can have shading and pasture, we have some really great setups.” (Perdue is also instituting new stunning systems at slaughterhouses, an important step.)

Me, I’d like to see more liberty, although the inevitable cost is some security. I can’t say for sure that an animal with more room to move, access to sunshine and a varied environment is happier, but that’s my best guess.

It has been about a decade since I bought conventional chicken or eggs, and I’m watching these developments with cautious optimism. It may not be long before a Perdue chicken, raised in a windowed chickenhouse with perches and hiding places, is what’s for dinner.