The United States reopened the Santa Teresa livestock port in New Mexico to Mexican cattle on September 24, expanding cross-border livestock trade after restrictions imposed over New World screwworm. The USDA-backed reopening restores one of the most important routes for Mexican feeder cattle entering the U.S. market. The decision matters for ranchers, feedlots and beef processors because domestic cattle supplies remain historically tight, but additional imports are not expected to translate into significantly cheaper beef in the near term.

Santa Teresa has historically been a critical component of the U.S.-Mexico cattle supply chain. The New Mexico port accounted for about 43% of Mexican cattle imports over the previous five years, according to USDA data cited by officials. Initially, approximately 750 to 1,600 cattle per day are expected to enter through the crossing, well below previous peaks of around 3,000 head. The reduced pace reflects additional inspection and treatment protocols designed to prevent animals carrying New World screwworm from entering the U.S. livestock system.

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For feedlots, particularly those across the Southwest and Southern Plains, restoring Mexican feeder cattle provides another source of animals at a time when available U.S. supplies remain limited. A smaller border crossing in Douglas, Arizona, resumed imports about a month earlier, with approximately 6,500 cattle entering the United States since operations restarted. Santa Teresa's larger capacity could increase those flows considerably, although the initial volumes represent only a fraction of the cattle needed to materially alter the national beef supply picture.

U.S. cattle supplies remain historically tight

The fundamental constraint facing the beef industry remains the size of the domestic herd. The United States had approximately 86.2 million cattle and calves at the beginning of 2026, the lowest inventory in roughly 75 years. Persistent drought and unfavorable pasture conditions have contributed to years of herd liquidation, while elevated input costs have complicated rebuilding decisions for cow-calf producers. The resulting contraction has tightened feeder cattle availability and left parts of the feedlot sector operating with fewer animals than available capacity.

That supply situation also explains why reopening the border is unlikely to produce an immediate decline in retail beef prices. Mexican cattle entering the United States are generally feeder animals that must gain substantial weight before slaughter. Industry estimates indicate that it can take roughly five to eight months for imported cattle to become slaughter-ready. Consequently, cattle crossing through Santa Teresa today will not immediately increase boxed beef production or the volume of ground beef available to retailers and foodservice companies.

The timing is especially important because U.S. consumers have already faced historically expensive beef. Ground beef prices recently approached $7 per pound, according to the source information, reflecting a combination of limited cattle availability and broader supply-chain pressures. Additional Mexican imports could gradually improve feedlot utilization and ultimately increase slaughter cattle supplies, but they cannot quickly replace the millions of animals lost during the multiyear contraction of the U.S. herd. The immediate benefit is greater feeder cattle availability rather than an instant increase in beef production.

New World screwworm remains the main animal-health risk surrounding expanded cattle trade with Mexico. The parasite can infest wounds in cattle and other warm-blooded animals, and untreated infestations can cause severe tissue damage or death. U.S. authorities therefore face a difficult balance: restoring a commercially important livestock trade route while preventing the pest from becoming established in domestic cattle populations. USDA has responded with enhanced inspections, treatment protocols and sterile fly releases intended to suppress reproducing screwworm populations.

The United States has reported only a limited number of active cases, but surveillance remains central to the reopening strategy. Officials have also been investigating how individual infestations occurred, including a case involving a horse in New Mexico. At the same time, USDA has not confirmed widespread infestation among wildlife or detected significant populations of wild screwworm flies in traps. That evidence has allowed authorities to cautiously expand livestock movements while maintaining additional biosecurity requirements at border inspection facilities.

The next question for livestock markets is whether additional U.S.-Mexico crossings can reopen without triggering new animal-health restrictions. USDA is expected to consider Columbus, New Mexico, as another potential entry point. Additional ports would improve flexibility for cattle movements and could help feedlots secure animals, but the broader supply challenge will remain. Mexican imports can supplement domestic production; they cannot substitute for rebuilding the U.S. breeding herd, a process that depends on producer economics, pasture conditions, feed costs and decisions to retain heifers.

For cattle producers and beef-market participants, Santa Teresa therefore represents an important reopening rather than a quick solution to high beef prices. More Mexican feeder cattle can strengthen supply-chain flows and help feedlots use available capacity, while strict animal-health controls remain essential. But with the U.S. herd near multidecade lows and biological production cycles measured in months and years, meaningful expansion of U.S. beef supplies will depend primarily on sustained domestic herd rebuilding.