Perdue Farms, the nation's fourth-largest chicken producer, said Monday that Minneapolis-St. Paul is one of the first five U.S. markets where all of its products come from chickens raised without any antibiotics ever.

The company is the early leader in a race among big producers to transform the sourcing and processing of chickens, particularly their treatment and nutrition.

The overuse of antibiotics in animals is believed to be linked to the growing number of superbugs, which are linked to drug-resistant bacteria that can affect human populations. By striving for the no-antibiotics-ever label, Perdue and other producers are taking that prospect seriously. Any product bearing the claim means the chicken never was given antibiotics, from birth to death.

The fanfare comes as other major chicken producers, like St. Cloud-based Gold'n Plump, recently announced their intention to wean all of its growers off the use of antibiotics over the next four years. Perdue started transitioning its massive operation more than 10 years ago.

Perdue first eliminated all use of human antibiotics in its birds before moving on to removing all animal antibiotics as well. To do so, the company had to clean up its facilities to prevent illness in the first place.

"In hindsight, we and the industry were using antibiotics to cover up not being as clean in the hatcheries as we should have been," Jim Perdue, chairman and grandson of the company's founder, told the Star Tribune. "It's a more aseptic environment now."

Just last week, the company — which processes 676 million chickens a year — announced that it has completed the final step in the multiyear transition, with 95 percent of its birds having never been given antibiotics.

The remaining 5 percent that are treated when they get sick are removed from the no-antibiotics-ever production line and sold separately without the label.

The company is rolling out the 100 percent no-antibiotics claim, market by market, as it ensures the full supply to a city is transitioned. Accompanying Monday's announcement will be a massive marketing campaign, including television, digital, outside billboards and skyway advertising in the Twin Cities, said Eric Christianson, senior vice president of marketing at Perdue.

This USDA-approved "no-antibiotics-ever" label is stronger than the label "antibiotic-free," which has confused consumers in the past. That label led many to believe some chicken in the marketplace had antibiotic residue in it. But the federal government requires all producers to stop treating chickens with drugs for a period before being killed, ensuring there is no residue in the meat.

"This change is totally driven by consumers," said Shelley Balanko, senior vice president of food-strategy firm the Hartman Group. And while research over the impact of pesticide use may or may not have on human health is equivocal, the connection between antibiotics and human health is much clearer, she said. Among natural and organic food shoppers, 39 percent cite no-antibiotic usage as a reason for purchasing a product, up from 31 percent in 2014.

When the public first began pushing the industry to reform, many growers were concerned that they would lose a large swath of their chicken population during a widespread sickness outbreak. But Jim Perdue said his company's chickens now have a better survival rate than before the changes.

"You're only as clean as the eggs coming into your hatcheries from the breeders," Perdue said. So, to keep the birds from ever getting sick without resorting to drugs, the company started wiping down every egg that entered its hatcheries. "We became, I think, one of the biggest consumers of baby wipes."

Many large chicken producers are following Perdue's lead, so the company is looking to stay ahead of the curve by addressing another concern that is increasingly becoming a consumer demand.

Animal care is their next big focus, Perdue said, "this is another big area we are moving forward on." That means adding more windows to bring in sunlight to its chicken barns and adding enhancements like perches and hay bales for the birds. It is also putting the birds to sleep before they are killed in order "to maximize reduction in stress" for the birds.

Perdue said the ultimate goal of the animal welfare improvements is to reduce stress and, in turn, double productivity.

Kristen Leigh Painter • 612-673-4767