A trip to the grocery store is no longer a simple “milk-and-bread” run anymore. Take a peek at the egg case, for example, and you will find endless choices, from standard grade-A large eggs to cartons labeled cage free, organic or free range.

Farmers here in Iowa are continually adapting to supply what their customers want, whether that’s cage-free or conventionally raised eggs.

“The beauty of this society is that you have a choice,” says Hongwei Xin, director of the Iowa Egg Center at Iowa State University (ISU). “If you like conventional (eggs), you can buy conventional. If you want cage free, you have that choice as well. Ultimately, it should be up to the consumer to decide what type of eggs they want to buy.”

Over the past year, several restaurant chains and grocery retailers, including McDonald’s and Wal-Mart, have announced plans to transition to cage-free eggs within the next 10 years.

Today, about 90 percent of the eggs raised in the U.S. come from conventional production systems, where the hens are housed in cages indoors, Xin says.

Here in Iowa, the top egg-producing state in the nation, most egg farms raise hens in conventional or “California-compliant” cages. In California, state law requires egg suppliers to raise hens in cages with 116 square inches of floor space.

An increasing number of Iowa egg farms are also adopting cage-free production systems to supply the retailers and restaurants that are switching to cage-free eggs.

However, when you see “cage-free” on an egg carton or a restaurant menu, it likely doesn’t mean what most people picture: a “free-range” chicken roaming and clucking outdoors on a green pasture.

“Total free-range production, as you can imagine, requires more land,” Xin says. “And when we have the threat of avian influenza disease, there’s always a potential risk (with outdoor production). Wildlife, geese and ducks, they carry certain viruses, like (the avian influenza outbreak) we had last year.”

Most cage-free hens are raised indoors in a relatively new type of production facility known as an aviary housing system, Xin explains.

These cage-free facilities, which are multi-level, allow the birds to move freely within the barn. During the day, the birds congregate on the barn floor, where there is a litter area for scratching and dust bathing.

At night, the hens fly up into a “colony area” in the barn’s second or third level (depending on the size of the barn) to perch and feed.

The hens lay their eggs on the top level, where there is a row of enclosed nesting boxes. “The idea is they can find a private place to lay eggs, to give them a sense of security,” Xin says.

The eggs then roll onto a conveyor belt, which collects and transports the eggs for washing and processing.

Although the hens are free to move around in an aviary housing system, only in organic production systems are chickens required to have access to the outdoors.

However, that doesn’t necessarily mean that the chickens are out on pasture. The “outdoors” could be a fenced lot or porches, although the U.S. Department of Agriculture recently proposed changing its organic livestock standards to require soil-based outdoor access. And it doesn’t mean that the chickens actually “choose” to go outside, especially in the winter when the birds would rather stay warm indoors.

While “cage-free” might sound like a better choice for animal welfare, research shows that each hen-housing system has its trade-offs, Xin says.

The Coalition for a Sustainable Egg Supply, a group of university researchers that included ISU’s Xin, completed a study last year comparing how different hen housing impacts animal welfare, food safety, production and employee health.

The study found that the hen mortality rate in aviary housing, or cage-free systems, was higher than in conventional production because of the “pecking order” in flocks. Unfortunately, larger hens in a flock will often peck to death the smaller, weaker hens.

Hens in aviary housing also tend to have more keel bone, or breastbone, injuries than in conventional systems, because they can injure themselves when flying inside the barn, Xin says.

“Challenges also include not as good of air quality (in cage-free systems), because when the birds are on the litter scratching a lot, they stir up the dust,” Xin says. Poor air quality can impact both the birds and the employees who care for them.

In addition, the study found that production costs in the Midwest are about 36 percent higher in aviary housing, which is a reason why cage-free eggs typically are higher priced at the grocery store.

No matter the production system, the study didn’t find any differences in food safety. All the hen-housing systems provide safe, high quality eggs that meet federal food safety standards.

So consumers should feel comfortable with whatever eggs they choose to buy, whether they prefer organic, cage-free or conventional, Xin says.

Iowa farmers will continue to adapt to the changing customer demand, while still providing nutritious, affordable food for all budgets.

“It’s good to have diversity, to give people the choice. That’s the bottom line,” Xin says.

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