LEXINGTON, KY. — U.S. Agriculture Secretary Brooke Rollins blocked all imports of live cattle, horses, and bison from Mexico on May 1, 2025, following the detection of New World screwworm within 70 miles of the U.S. border. The parasitic fly lays eggs in living animals, and its maggots consume host tissue, posing a threat to livestock health.

The import ban affects a major source of U.S. cattle supply, as Mexico accounted for approximately 62% of all U.S. cattle imports between 2020 and 2024, according to U.S. Department of Agriculture (USDA) data. The restriction removes a large number of animals from the domestic beef supply chain, which could influence market dynamics for ranchers and consumers.

Jason Cleere, professor and extension beef cattle specialist at Texas A&M University, said the removal of Mexican cattle from the supply chain would affect domestic pricing. "If you take that number of cattle out of the beef supply chain, yes, it's going to increase the value of the rest of the calves that ranchers are selling domestically here." Cleere said that rising operational costs have strained producers despite record-high cattle prices. "Our expenses have gone up just like your beef prices have gone up. I don't want our ranchers to be painted as the bad guys that are evil that are making all the money. We're just finally caught up to where we can make a good living now."

The U.S. cattle herd has been in long-term decline, standing at 86.2 million head on January 1, 2026—the lowest level since 1951. Contributing factors include drought, rising operating costs, international competition, and industry consolidation. The number of U.S. cattle operations fell from 882,692 in 2017 to 732,123 in 2022, a 17% drop.

Bill Bullard, CEO of R-CALF USA, noted the decades-long reduction in national herd size. "We have likewise lost the cows that they once maintained. So we have seen our herd shrink at an alarming rate for the past several decades."