Whole Foods Market harbors the same hopes for its chickens that many parents do for their kids: That they’ll get plenty of fresh air, live at home until they reach maturity and avoid gaining weight so fast that they can’t walk.

These are a few of the animal welfare practices the retailer hopes to encourage with a humane meat-rating system being piloted in the South and scheduled for national expansion early next year. If the five-step, color-coded labeling system works as planned, it could allow American consumers at many supermarket chains unprecedented levels of specificity when it comes to choosing meat to match their principles.

Developed by the Global Animal Partnership, a nonprofit group made up of farmers, scientists, retailers, sustainability experts and animal welfare advocates, the rating system aims to address growing consumer concerns over the way animals are raised for food. It could also, not coincidentally, boost sales for certified farmers and participating stores, likely to include another unidentified major national retailer and restaurant group in the coming year, according to the nonprofit.

Its five-step approach establishes baseline standards for all meat sold in the store, while offering producers an opportunity to achieve higher ratings as their animal welfare standards improve based on the program’s benchmarks.

So, for example, the highest rating (5+, colored green) would go to a chicken that, among other things, had been bred, hatched and raised on a single farm, lived year-round on pasture with at least 75 percent vegetation and had legs that were healthy enough to support it by the time it reached market weight. And the lowest rating (1, colored yellow) would reflect adherence to several dozen baseline provisions about feed, antibiotics and treatment, but also a provision that the animal must not have been caged or crowded.

Slightly different standards are in place for pork and beef, but all three categories emphasize animal comfort and health, pasture time and remaining on one farm, even through slaughter. Although most organic standards are not part of the program, organic producers can and have become GAP certified as well.

While Whole Foods Market was the driving force behind developing the standards, GAP Executive Director Miyun Park believes they will move well beyond the chain, spurring “massive improvements in the way animals are raised in this country.”

Numerous surveys, from universities to Gallup to the Farm Bureau, show that Americans have developed a heightened interest in farm animal welfare. Concern over the topic has fueled several recent ballot initiatives, popular movies (“Food, Inc.”) and books (“Eating Animals,” “The Omnivore’s Dilemma” and “Animal Factory”).

“We get an enormous amount of questions from customers who want to know everything about the meat and animals, really detailed questions,” said Anne Malleau, global animal production and welfare coordinator for Whole Foods Market. But the program is also aimed at customers who don’t want the gory details so much as assurances that their “food has been humanely produced,” Malleau said.

Although the company has no set formula for pricing GAP levels, it did share some examples from an Atlanta-area store that started rolling out the program in 2009. Grain-fed rib-eye steak rated a Step 1 costs $14.99 per pound, while local grass-fed rib-eye, rated Step 4, costs $15.99 per pound. And Canadian bone-in pork chops rated Step 1 cost $6.99 per pound, while local bone-in pork chops rated Step 4 cost $7.99 per pound.

Whole Foods says that about 1,000 farms have been or are going through third-party GAP auditing, and a few hundred are awaiting the process. Most are small, regional producers, but they also include big, national names like Pennsylvania-based chicken producer Bell & Evans (Step 2) and Niman Ranch pork producers, which are still in the auditing process.