USDA Raises Import Standards
For Mexican Cattle April 1

AUSTIN — The U.S. Department of Agriculture has raised health standards for importing Mexican feeder cattle to protect U.S. animals from tuberculosis, a bacterial infection that can cause lesions in the lungs, lymph nodes, or other internal organs.

On April 1, feeder cattle (steers and spayed heifers) from Mexico will enter the U.S. under health regulations published more than a year ago in the Federal Code of Regulations by USDA's Veterinary Services. By 2003, the USDA will tighten regulations again, when international rules will require exporting countries to fully meet U.S.-equivalent standards for cattle TB eradication.

"Texas cattle producers import approximately a million Mexican feeders each year. On April 1, entry regulations for these animals will be tied directly to the prevalence of TB in their Mexican state of origin, or their region within a Mexican state," commented Dr. Linda Logan, Texas state veterinarian and head of the Texas Animal Health Commission, the state's livestock health regulatory authority.

"Mexican feeder animals have offered excellent opportunities for cattle producers," she said. "Cattle TB, however, continues to be a problem in many Mexico states, and we must continue to assure that imported animals are properly tested for TB before they enter Texas. Infected animals can spread the disease by coughing, bellowing or snorting. The bacteria-laden aerosol that they expel can be inhaled by animals nearby or could contaminate feed. If we have TB introduced into our herds, our ability to trade interstate or internationally would be restricted."

Logan pointed out that in April 2001, USDA's Veterinary Services published an interim rule requiring Mexican feeder steers to originate from herds that had recently been tested for TB. USDA then agreed to grant waivers to the whole-herd test if Mexican states could demonstrate sufficient progress in eradicating TB prior to April 2002.

During the past five months, USDA-sponsored teams have conducted in-depth TB status reviews in 16 Mexican states with active TB eradication programs. The teams, comprised of state and federal regulatory veterinarians, trade association representatives and laboratory specialists, determined that only one Mexican state and portions of five other states could be granted a waiver of the whole-herd test requirement.

Feeder cattle from most other Mexican states will have to originate from tested herds and then also undergo an individual animal test. Some states will be prohibited from shipping feeder cattle to the U.S. due to inadequate TB eradication programs.

"These rules are intended to protect the health of U.S. livestock," noted Logan. She pointed out that, in the early l900s, nearly five percent of U.S. cattle herds were infected with TB. Today, she said, the disease is extremely rare in U.S. herds. However, more TB-lesioned cattle are being detected at slaughter, and eartags indicate that many of these animals are of Mexican origin.

"Prior to pasteurization, or heat treatment of milk, humans could contract the disease from infected cows. Today, human TB cases in the U.S. are rarely, if ever, traced to the cattle form of the disease, due to a combination of slaughter surveillance, pasteurization of milk and disease eradication," she noted.

"We have worked closely with Mexico on TB eradication since l988, when the USDA began offering training and technical support," she said. "Since l994, Mexican cattle have been imported under a 'consensus agreement' established by the state veterinarians in Texas, California, Arizona and New Mexico. At least 20 other U.S. states incorporated the consensus document into their state rules. The new federal rules will provide a more stringent, yet uniform program for imports."

A bi-national committee, with eight American and eight Mexican representatives, also has been meeting three times yearly to formalize status review findings and discuss TB, brucellosis and trade issues. Logan also pointed out that, over the years, groups of regulatory personnel and producers from California, New Mexico, Texas and Arizona, and other participating states conducted program reviews in Mexican states. She said they monitored TB prevalence in Mexican herds, inspected laboratories, checked slaughter surveillance techniques, and shared ideas and experience.

"The new federal requirements will advance the TB eradication effort by protecting all U.S. states that may receive Mexican cattle," pointed out Dr. Richard Ferris, area veterinarian-in-charge for USDA's Veterinary Services in Texas.

"The USDA-sponsored teams will continue to review Mexican states as they make progress, so the regulations for each state could change." He said USDA specialists in Riverdale, Maryland, are preparing maps delineating the boundaries of TB regions within Mexican states. The maps are to be ready prior to April 1.

"As of April 2002, only feeder cattle from a designated portion of Sonora, which borders Arizona, may be imported into the U.S. without a TB test, because this area has an infection rate of less than one infected herd per 10,000," Ferris commented.

"As always, all Mexican cattle must be officially identified with a blue eartag imprinted with the name of its Mexican state. The animals must also be accompanied by a certificate of origin, which documents where the animals came from," explained Dr. Suzanne (Suzy) Burnham, TAHC's new b-inational liaison, who is stationed in San Antonio. She said the imported animals must also carry an "M"-brand on the hip and will be inspected for fever ticks at the import station on the border.

"Feeder cattle must have a negative TB skin test before being imported if they come from Yucatan; a designated portion of Coahuila, our direct neighbor to the south; Sinaloa; the remaining portion of Sonora; or designated segments of Aguascalientes or Jalisco," Dr. Burnham. She said these states or portions of states have between one and five infected herds per 1000 herds.

Burnham explained that an accredited veterinarian conducts a TB skin test by injecting tuberculin into the skin or "caudal fold" under the animal's tail. The site is examined 72 hours later for redness, swelling or other reaction, which indicates the animal may have been exposed to or infected with TB.

"Mexican states that did not obtain a whole-herd test waiver from the USDA include Tamaulipas and portions of Baja California, Campeche, Chihuahua, Coahuila, Durango, Jalisco, Nuevo Leon and Veracruz," said Burnham.

"These states will export feeder cattle under the interim rule because they have an infection prevalence greater than five infected herds per 1000 herds in the state or area.

"The parent herd (including the feeder cattle being exported) must have tested negative for TB within the previous 12 months. This will prevent cattle exporters from assembling untested feeder animals from a number of sources shortly before shipment," explained Burnham. She pointed out that each of the exported animals also must be individually TB tested again. The animals are to move under an import permit from USDA.

"The whole herd test concept is vitally important, as animals that have been exposed to TB can still test negative for a period of time if they are incubating infection. By requiring the entire herd to be tested, we have a greater probability of determining if there is a health problem and we can restrict the entry of animals from that herd. The individual animal retest then gives us greater assurance that the feeder cattle haven't been incubating disease," explained Ferris.

"Feeder cattle from some Mexican states or portions of states will be allowed to enter the U.S. only directly to slaughter. These animals are from areas that have not made sufficient TB eradication progress or met program review criteria for inspection, testing, or surveillance," said
Ferris.

"Prior to entry for slaughter, the animals must have a negative TB test and must be accompanied by the proper paperwork, including an import permit and official eartags."

Logan said TAHC also will closely scrutinize Mexican roping and rodeo cattle already in Texas.

"We will be checking these animals at events and practice pens to ensure that these animals have had their required post-entry TB tests," she said. "The TAHC requires that these animals be tested every 12 months for TB. We can't have infected imported stock mixing with valuable animals at events. We urge Texas producers to do their part by making sure these roping steers are tested on an annual basis."