The fast-casual restaurant with food made with humanely-treated and environmentally-friendly ingredients may be forced to ease some of its beef requirements as beef supplies deplete.

The beef used by Chipotle in its Food With Integrity program requires that products from its suppliers meet the company’s naturally raised standards. The Chipotle website says the beef served by the chain was raised without the use of antibiotics or added hormones.

With cattle numbers falling to a 60-year low, Chipotle is having a hard time purchasing beef meeting its requirements. Almost all of the beef used by the restaurant last year met its guidelines, however Bloomberg reports between 80 percent and 85 percent of the beef used by the burrito chain this year meet those same requirements.