Due to the continued drop in beef production in the United States and a shrinking beef supply, Chipotle has announced that it may start using meat from cattle that were treated with antibiotics due to illness. The company still will refuse beef from cattle that were given antibiotics to prevent disease or promote weight gain.

Previously, the restaurant chain has accepted only antibiotic-free animals. Chris Arnold, a spokesman for Denver-based Chipotle, told Bloomberg Businessweek that the motivation for the change isn’t to increase its supply of steak, although Chipotle hasn’t been able to get enough naturally raised beef to meet customer demand. This year, about 80 percent to 85 percent of the beef sold at Chipotle’s more than 1,500 stores has been naturally raised, compared with almost 100 percent last year, Arnold said.

“The change was really rooted in the belief that it’s not the use of antibiotics for the treatment of illness that is the problem,” Arnold said. “The problem is the copious amount of antibiotics that are used to promote growth.”

Allowing sick animals treated with antibiotics to remain in Chipotle’s supply chain would increase the amount of beef available to the company, said John Nalivka, a former U.S. Department of Agriculture economist and president of commodity researcher Sterling Marketing Inc. in Vale, Oregon.

“That opens up their supply quite a bit,” he said. Chipotle will be able to buy cattle outside the USDA’s Never Ever 3 program, which says cattle may never be given antibiotics, growth promotants or fed anything with animal byproducts.

“That’s really the piece that will add the greatest supply if you take that stipulation away,” said Nalivka, who says supply is dwindling.

Source: Bloomberg Businessweek

UPDATE: Chipotle announced that it may alter its beef purchasing policies. No change has yet been made. The article has been edited to reflect the change.