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Organic? Free-Range? Cage-Free? When It Comes To Eggs, Which Should You Buy? | Serving Up Science

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When it’s time to pick up eggs at the supermarket, making a choice can be overwhelming. Should you be buying cage-free or free range? Organic or conventional? What is the difference between all of the terms you see on the carton?

In previous episodes, we’ve tackled how some of the words on food labels are meaningless or take advantage of a consumer’s lack of knowledge to make a sale. So let’s break down these terms.

In the U.S., about 97 percent of egg-laying chickens are confined to what’s called "battery cages."

These cages hold 5 to 10 birds each and are supposed to have at least 67 square inches per hen.

That’s a smaller space than an 8.5-by-11-inch piece of paper. That’s the minimum standard from United Egg Producers, who also estimate that around 15 percent of chickens are raised in cages that don't even meet that standard.

But what does that limited room mean for the birds?

It’s stressful to put it mildly. It’s interesting to note that overall bird mortality rate is actually lowest in cages, but there are a lot of factors involved that make that so, from the birds used - to the potential for parasites and predation.

Battery cages are really designed for easy egg collection -- the wire floor of the cage is slightly sloped. So, when a hen lays an egg, it rolls gently down to a conveyer belt and is whisked away to be prepared for grocery store shelves.

Aside from battery cages there are many alternatives.

Hens can be raised in barns, aviaries, and what are called "enriched colony cages." In a barn system, a large flock wanders freely throughout an entire barn where there are perches, sawdust for scratching, food and water at various locations, and nest boxes.

Some barn systems even provide a curtain by the nest box for egg-laying privacy.

Aviaries kick luxury up a notch. They can be a lot like barns, but also offer multiple levels that birds can walk up or fly to. Hens might have more space and places to escape other birds harassing them.

Barns and aviaries might allow the birds to go outdoors, which allows them to be considered “free range" animals.

There are some drawbacks to these more open systems, however. More space means more opportunity for hens to lay eggs outside the nest box. These eggs often are pecked, crushed, and eaten by curious hens, meaning fewer eggs for the farmer to sell. Hens are also more likely to injure themselves in aviary systems -- for example, falling from perches and fracturing their breast bones.

Let’s get to the enriched colony cage.

These chickens are still caged, but have more room for activities like dust bathing, a perch and private nest box for egg laying. They don’t get the vertical space like an aviary, but are less likely to fall and injure themselves.  Seemingly still a more comfortable life than battery cages.

But do birds really notice a difference between these options or are producers just making consumers feel better about buying an egg from a hen that had privacy while laying eggs?

Nobel laureate ethologist Konrad Lorenz described watching battery caged birds as truly heart-rending, because a chicken will try to crawl beneath cage mates to search for cover. To quote him, “The worst torture to which a battery hen is exposed is the inability to retire somewhere for the laying act.”

The best type of egg to buy is really up to you and depends on your priorities. Regular eggs are usually less expensive, but cage-free eggs make a big difference in the lives of the birds.

As for free-range eggs, which come from birds that get to be outside...

Those chickens may not necessarily experience a better existence. There are no set standards for what constitutes ‘free-range’ or ‘pasture-raised’, so these birds might have access to a small yard, or be raised completely outdoors.Free-range birds may also be at greater risk for predation and parasites which can certainly add to their stress levels. There are actions that farmers can take to reduce the risk, but it’s difficult to impossible for consumers to know if protections like fencing and wire were in place.

Moving on to organic eggs - this means that the chickens had some outdoor access and were also cage-free as well.

But, organic also means that farmers aren’t allowed to provide synthetic amino acids to their birds despite that they improve chickens' overall health. So they might not get the same level of nutrition.

Sick hens cannot be treated with antibiotics and sold as organic later, so because of that rule, some farmers do not use antibiotics at all. Which could mean unnecessary suffering. And these rules from the US Department of Agriculture apply to all organic meat.

There are many animal scientists who believe organic production is cruel because of the lack of antibiotics.

Organic eggs also aren’t healthier for consumers. Nor are free-range eggs, for that matter.

It seems each system has pros and cons for both the hens and the farmers.If animal welfare is a big priority, consumers can look for stickers on their products that say "Certified Humane" and "Animal Welfare Approved" for assurance the birds are treated well.

There are also people who say just don’t eat eggs, though that’s probably not likely to catch on globally.

When it comes to the egg business, there are real ethical concerns. A big one is that most hatcheries that supply chickens to farms — and by the way, this includes cage-free or free-range farms — practice "chick culling."

This is a fancy way of saying that the male chicks are slaughtered, often by grinding them alive or gassing them.


On a positive note, United Egg Producers committed to eliminating culling by 2020 and early sex detection through modern technologies are allowing males to be identified early and raised for meat, eliminating the need for culling.

The kind of eggs you buy is up to you, but  hopefully now you have a little more information about what you see on the carton when you’re at the supermarket.

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