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New Mexico State University

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NMSU, Valles Caldera National Preserve partner for unique bull performance testing program

The majestic high-altitude, grass-filled meadows coupled with elite genetics representing the beef industry's top sires has positioned the Valles Caldera National Preserve to become a unique performance testing center for high-altitude bulls.

Dr. Tim Holt, veterinarian with Colorado State University, tests a bull for bovine high altitude disease while NMSU's Manny Encinias holds the cow's head. The test is part of NMSU's high-altitude testing project at the Valles Caldera National Preserve in the northern New Mexico mountains. The College of Agricultural, Consumer and Environmental Sciences program is the first time bulls have been tested in an all-natural environment for the hypertension disease that plagues some cows at high altitudes.(NMSU photo by Jane Moorman)

Identifying beef genetics that can thrive in an all-natural grazing environment at high altitude is the goal of the project pioneered by New Mexico State University's Manny Encinias, and is taking place on the national preserve in the mountains of northern New Mexico this summer.

"Grazing cattle at high altitude comes with inherent risk due to their susceptibility of developing hypertension," said Encinias, a beef cattle specialist with NMSU's Cooperative Extension Service and coordinator of the 2009 grazing contract with the Valles Caldera Trust.

Cattle, like humans, can be genetically predisposed for hypertension at higher altitudes, known as bovine high-altitude disease or brisket disease, when they graze above 7,000-foot elevations for extended periods. The inability to process oxygen efficiently is a key health issue that hampers cow/calf operations in the Rocky Mountain region. Establishing a performance-testing program at Valles Caldera has given seed stock producers throughout the U.S. the opportunity to identify individual bulls and begin to better understand the impact a bovine's genetic pedigree and previous management have on their ability to perform at higher altitudes without developing high blood pressure and hypertension.

In June, 113 coming two-year old bulls were delivered to the 89,000-acre preserve, formerly known as the historic Baca Ranch, from interested seedstock producers actively involved in the New Mexico Beef Cattle Performance Association (NMBCPA).

NMBCPA is one of the oldest performance-testing organizations in the United States and serves as the administrator and owner of the Tucumcari Bull Test Facility in eastern New Mexico. Nationally recognized as one of the leaders in performance testing, the Tucumcari facility was one of four centralized performance-testing facilities in the nation developed almost 50 years ago to promote the selection of superior beef cattle genetics.

At 9,000 feet in elevation, the lush green pasture of the Valles Caldera makes the current program unique in that it is the highest altitude centralized performance test in the nation. Furthermore, the program is gaining national attention from cattlemen because the bulls are being developed on a 100-percent grass diet.

"With the exception of salt and minerals these bulls are expected to get out and make it happen on grass alone," according to Encinias. "There's no 'grain for gain' in this program." After all, a bull's working environment is out on grass pasture, Encinias is quick to point out.
National expert on bovine high mountain disease Dr. Tim Holt is a veterinarian and assistant professor at Colorado State University's school of veterinary medicine and biomedical science. He performed the pulmonary arterial pressure (PAP) test on the bulls to evaluate their individual adaptation to the high altitude after 60 days on the preserve.

"When a bull comes from lower altitudes and walks into high elevation, he gets hypoxia because his oxygen is decreased," Holt said of the health condition. "Jugular distention in the animal's neck is one of the first signs. As the hypertension symptoms progress, this eventually leads to congestive heart failure."

Holt conducted the PAP test on each of the bulls, while Encinias' NMSU team, participating producers and Dr. John Heidrich, a local veterinarian and his students from Central New Mexico Community College's veterinary technician program, weighed the bulls and removed hair samples for future DNA marker testing.

During the PAP test, a cardiac catheter is placed in the bull's right jugular vein and blood-flow fed through the heart into the main pulmonary artery that connects the heart to the lungs. From that position the heart's function is measured by the blood pressure.

The bulls displaying the early signs of hypertension were removed from the herd and sent back to their home ranches at lower altitudes.

"What makes this program so important is that high altitude is the number one killer of cattle on the mountain. It's not anything to lose 3 to 5 percent and greater of a herd," said Holt, who has studied bovine high mountain disease since 1980 and has performed PAP tests on more than 100,000 head of cattle. "The most devastating loss I've seen is 80 percent of the calf crop. The fact that this disposition is genetic makes it even more devastating, because if you get it into the herd then things get worse in a hurry."

According to Holt, the higher the altitude in which the bulls are PAP tested the more accurate the test results. "The fact that these bulls are on all grass, free from growth promotants and grain, further increases the test's accuracy," Holt said.

Since the region's closest high-altitude testing facility, located in Hesperus, Colo., stopped gain-testing bulls a few years ago, it left a large void in the marketplace from which local and regional producers could purchase reputable, performance-tested bulls with good PAP-scores, said Encinias.

On Saturday, Oct. 10, the Valles Caldera Trust will team up with NMSU and the NMBCPA to host the first-ever "Top of the Valle" high-altitude bull sale on the preserve.

"This will be a great opportunity to purchase bulls with progressive genetics, but more importantly those with the ability to live in the high country," said Encinias. "Only the top 35 percent of the 113 bulls deemed low-risk of developing hypertension, but also have good performance potential, will be offered for sale."

More information on the "Top of the Valle" performance test and sale can be accessed at http://aces.nmsu.edu/highcountrybeef or http://www.vallescaldera.gov.