SALT LAKE CITY — Alarmed over the impact to the domestic food supply, Utah Republican Sen. Mike Lee and 11 other members of Congress sent a letter to Justice Department Antitrust Division Assistant Attorney General Makan Delrahim, asking him to immediately open an investigation into the acquisition of a Colorado lamb processing facility.

 “(Mountain States Rosen) is a cooperative owned by more than 145 American families. Reports tell us that its Greeley facility is the second largest lamb packaging plant in the United States, processing approximately 350,000 lambs annually, over 6,000 per week, with an annual capacity of nearly 800,000. MSR accounts for about one-fifth of the entire U.S. lamb market,” the letter reads.

The letter says JBS, the new owner, is preparing to completely shut down all lamb processing at the site.

“It is our understanding that JBS intends to permanently destroy all of the lamb processing equipment as soon as this week,” the letter continues.

 “We urge you to immediately open an investigation into this acquisition and demand that JBS cease from any irreversible actions that might harm the ability of American sheep ranchers to get their products to market until the department can determine how best to protect competition in this significant part of America’s food supply,” it concludes.

JBS spokesman Cameron Bruett said the facility was acquired during a recent bankruptcy auction.

“While we acquired the facility and certain assets, we did not acquire the business. During this process, we proactively worked with Mountain States Rosen to ensure there would be no disruption to U.S. lamb producers as operations were discontinued.”

Bruett said another processing facility is set to open in Brush, Colorado but that facility harvests the lambs and does not prepare them into cuts, limiting market options for producers.

Alarm over the acquisition was raised earlier this week by Sanpete County sheep rancher Carson Jorgensen, who sent a letter to Vice President Mike Pence, members of Congress, Utah Gov. Gary Herbert and others detailing the impacts to sheep ranchers in 15 states if the facility closes.

Jorgensen said the decision by the new owner leaves tens of thousands of lambs that are ready for slaughter stranded in feedlots, as well as the hundreds of thousands of lambs that will be coming off summer ranges.

“Ranchers do not have the feed or resources to hold onto their annual production and there is simply nowhere to send their lambs,” he wrote to Pence. “The limited number of lamb plants are running at capacity and small, local processing plants will never be able to process the volume.”

The vast majority of the U.S. meat industry is controlled by only a handful of companies, a consolidation that ranchers have complained about for years. Lamb producers are particularly undercut by their foreign competitors, including JBS, which Jorgensen said is one of the largest foreign importers bringing lamb into the United States.

Senators joining Lee on the letter include: Sens. Steve Daines, R-Montana, John Barrasso, R-Wyoming, Mitt Romney, R-Utah, John Thune, R-South Dakota, and Michael Rounds, R-South Dakota.

Representatives signing the letter include: Reps. Rob Bishop, R-Utah, Chris Stewart, R-Utah, Greg Gianforte, R-Montana, Devin Nunes R-California, Dusty Johnson, R-South Dakota, and Liz Cheney, R-Wyoming.