DENVER – Customers looking to enjoy some carnitas at area Chipotle restaurants might have to choose another menu for the item being. Chipotle Mexican Grill Inc said it would suspend pork sales at about one-third of its US restaurants, following a routine audit that revealed one of its suppliers was not complying with its animal-welfare standards.

An inspection of the undisclosed supplier exposed some inconsistencies in the chain’s animal welfare protocol, communications director Chris Arnold told Reuters. Suppliers must raise pigs with access to the outdoors or in deeply bedded barns to improve their comfort. The standards also prohibit the use of antibiotics.

Chipotle will not serve “carnitas” at one-third of their restaurants, rather than use conventionally raised pork, Arnold said.

The popular QSR burrito restaurant is looking at a number of options to address the shortage of pork supply, including procuring additional pork from existing suppliers or finding more suppliers. Meanwhile, Arnold explained, Chipotle could resume its relationship with the suspended supplier, if they become compliant with the company’s standards.

Denver-based Chipotle, known for serving antibiotic-free meat and organic produce, posted third-quarter same-store sales growth of nearly 20 percent.