Cattle detained in the pens of the Unión Ganadera Regional de Chihuahua, at the Jerónimo-Santa Teresa border crossing in Ciudad Juárez, Mexico, on November 27, 2024, after the United States stopped imports of Mexican cattle due to the presence of screwworm.
Anadolu | Anadolu | fake images
Cattle farmers in Texas and across the country are concerned that screwworm, a parasitic fly once eradicated in the U.S., is threatening to return from the Mexican border, and President Donald Trump's recent talks about importing beef from Argentina are not a long-term solution for a beef supply chain already under strain or for consumers who have watched beef prices reached record levels.
The New World screwworm is a parasitic fly that lays eggs in the open wounds of warm-blooded animals. The larvae then emerge from the eggs and hide in the animals' tissue to feed on them. If detected early, the sick animal can be treated and survive. Human cases are rare but can be painful and require medical attention. In August, the U.S. Department of Agriculture said in a statement that the Department of Health and Human Services and the Centers for Disease Control and Prevention identified a case of the flesh-eating parasite in a person in Maryland who returned to the United States after traveling to El Salvador.
The New World screwworm was successfully eradicated from the United States in 1966. But the Maryland case and other recent appearances in Mexico have ranchers in Texas and across the country nervous. On October 6, Mexico's National Agri-Food Health, Safety and Quality Service confirmed another case of the carnivorous screwworm parasite in Nuevo León, a city bordering the United States. This is the second confirmed case in the country in approximately two weeks.
“Texas is a major contributor to the beef industry,” said Andrew Coppin, co-founder and CEO of ranch management company Ranchbot Monitoring Solutions. “There are millions of cattle on the southern border alone.”
The U.S. Department of Agriculture has closed the border with Mexico to intermittent imports of live cattle, bison and horses starting in 2024 due to the spread of the New World screwworm. The border is currently closed. Before the shutdown, Mexico was an exporter of calves to the US, and USDA data showed that the US imported more than one million head of cattle annually, about 3.3% of the total US calf crop.
James Clement III, a sixth-generation Texas rancher, told CNBC that the key to eradicating the screwworm threat is years away. To combat the spread of the flies, the USDA disperses sterile flies in the area to stop mating, a scientific method known as sterile insect technique (SIT). It was the reason for the success of fly eradication in the U.S. But Clement said the flies used previously were brought from Panama and although the USDA has said it is committed to developing a national sterile fly production facility, “that's at least two or three years away. By then it will be too little, too late,” he said.
The USDA did not respond to a request for comment for this article. Appearing on CNBC's “Squawk Box” Tuesday morning, U.S. Agriculture Secretary Brooke Rollins said, “I think you're going to hear more about exactly what that looks like,” in response to a question about the idea of importing Argentine beef.
Clement, whose family business has operated multiple ranches for the past 400 years, said American ranching has evolved and become more efficient. While this is good for production, in times of threats like biological hazards like the screwworm, it is a challenge.
“Now we need less manpower, so it would be difficult and challenging to detect infected cattle,” he said. “We don't have people to check each head of cattle daily. Most of these cattle are free-range and the pastures are large.”
Stop the spread of screwworm
The USDA, along with Mexico, has been monitoring nearly 8,000 traps in Texas, Arizona and New Mexico since July. More than 13,000 screening samples have been submitted and no NWS flies have been detected.
But Clement says, “This is spreading rapidly. A year ago, screwworm was already in southern Mexico, then it spread to central and northern Mexico. Now it's happening just south of our border. It's not a question of if screwworm spreads to the U.S., but when.”
Clement said the situation adds to the imbalance between supply and demand in the livestock industry, which has already increased due to the drought. Beef prices have risen to record levels after ranchers reduced their herds due to drying land used for grazing. As a result, feed costs increased.
The price of live cattle futures over the past year.
According to government data, in July 2025, the US cattle herd was approximately 94.2 million head, the lowest inventory since 1951.
Coppin tells CNBC that the key component to increasing herd size is water.
“Usually ranches have thousands of acres and livestock,” Coppin said. “Less grassland as a result of less water equals smaller herds.”
He estimated that 30% of the United States is still in drought conditions.
“The question ranchers are asking is: Will I have enough feed to feed my herd? That's why pastures are important. Feed is a big input cost that reduces ranchers' margins,” he said.
Coppin said that while importing beef from Argentina may reduce the cost of beef for consumers (futures had fallen sharply after Trump's comments but have since risen again), for ranchers facing drought and screwworm, the incentives to increase herd size are diminishing.
“Livestock farmers don't want their product to be substituted,” Coppin said.
Recently, some American ranchers have begun taking steps to begin rebuilding their herds. However, ranchers and beef supply chain experts like Coppin say it takes about two years before beef production ramps up because it takes time to raise adult cattle.
The National Cattlemen's Beef Association said in a statement Monday after President Trump raised his idea of importing beef from Argentina over the weekend that it was urging Trump and Congress to allow the market to operate rather than intervene and harm rural America.
“This plan only creates chaos at a critical time of year for American livestock producers, while doing nothing to reduce prices in grocery stores,” said Colin Woodall, executive director of NCBA.
Republican Sen. Deb Fischer of Nebraska urged President Donald Trump to reconsider his proposal that the United States buy beef from Argentina in a social media post Tuesday.
“We've had a massive run on beef over the last decade,” Rollins said Tuesday on CNBC. “Massive consolidation, which has not been good for our livestock industry, and we've offshored a lot of that. There's a really major realignment that has to happen so we can start offshoring and reshoring for our beef producers, for our ranchers,” he said.
“Prices are high and the president is very focused on keeping his promise to lower grocery prices… but you're also going to hear from us in the next few days about what we're going to do to incentivize, open up new land and make it easier to become a rancher,” Rollins continued. “We have a pretty big package ahead of us,” he added, noting that the CNBC appearance was the first time he mentioned the plans publicly.
The NCBA cited Argentina's “deeply unbalanced trade relationship” with the United States. In the last five years, Argentina has sold more than $801 million of beef in the US market. By comparison, the United States has sold just over $7 million worth of American beef to Argentina, according to NCBA data. He noted that Argentina also has a history of foot and mouth disease, which if brought to the United States, could decimate national livestock production.
Rollins estimated during his CNBC appearance that 2 million of the 12 million metric tons of beef consumed annually in the U.S. come from abroad, and any increase coming from Argentina “wouldn't be much” compared to that total, especially in light of the USDA's concerns about foot-and-mouth disease.
Clement said the United States should not focus on the government intervening and trying to regulate markets.
“The market will take care of itself,” Clement said. “We need the government to prevent and eliminate screwworm. Then we can recruit the next generation by saying, 'livestock farming is a profession you can do to take care of your family and have a good quality of life. The government will take care of us through biosecurity and prevention of animal diseases. Without manipulating the markets.'”
