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Study Highlights Brisket Disease in Cattle Raised at High Elevations

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In a study by New Mexico State University and the New Mexico Beef Cattle Performance Association, researchers are conducting high altitude cattle performance tests on bulls to determine which animals are susceptible to a disease known as brisket disease, or otherwise known as high altitude disease, dropsy or pulmonary hypertension. Researchers hope their work will help ranchers develop a genetic line of cattle resistant to high altitude disease.

Brisket disease in cattle is primarily due to oxygen shortage. Available oxygen is reported to be 17 percent less at 5,000 feet than at sea level and up to 20 percent less at 6,000 feet. Oxygen shortage at higher elevations causes an increased resistance to blood flow in arteries in the lungs. The resulting high blood pressure can reportedly force fluid out of the vessels and into surrounding tissues. In cattle the swelling can spread up the neck to the jaw and/or along the underline of the belly.

Cattle taken to higher elevations for summer pasture above 5,000 feet are reported to be at risk, and incidence of the disease increases in susceptible animals as elevation increases. Susceptibility to brisket disease is inherited; the problem has been reported to be more common in calves and yearlings that are pastured on high mountain pastures.

According to an article in Western Cowman, factors which may contribute to the disease, include migrating parasitic larvae, cold weather stress, and breathing dust or smoke. Nevertheless, the biggest risk is genetic susceptibility. Symptoms of brisket disease in cattle are reported as weakness, diarrhea, bulging eyes, and difficulty breathing. Cattle with the disorder that are moved will often drop to the back of the herd sometimes lying down due to breathing difficulties.

A veterinarian from Colorado State University, Dr. Tim Holt, has studied the disease for many years. Holt utilizes a test that was developed in humans for measuring pulmonary arterial pressure or PAP. The PAP test will determine which animals are at risk for brisket disease by detecting the early stages of the problem.

Holt reports that some cattle are less susceptible than others, and some breeds appear to be more susceptible though the disease has been reported in all breeds. There are cattle in other high-elevation regions of the world that do not suffer pulmonary hypertension at all. Veterinarians speculate that ani-' mals susceptible to brisket disease died off and the "strongest have survived."

The problem has also been reported in feedlot cattle at lower elevations, as the animals get heavier, since the heart must work harder to support a larger animal.

Studies are continuing on feedlot cattle as well, according to Holt. The issue for some cattle producers is that many artificial insemination producers are at low elevations, and some of those bulls could carry predisposition to the disease, thereby continuing susceptibility to the condition. Accordingly, some producers who market bulls to customers at higher elevations are PAP testing the bulls.

The study in New Mexico aims to develop a genetic line of altitude-resistant cattle, since the disease kills three to five percent of the estimated 1.5 million head of cattle raised annually in the United States at high elevation.

Ranchers at higher elevations believe the research is important.

"A person buying cattle can't afford to have bulls die on them," said Bob Anderson, a rancher who raises bulls at a ranch at 6,000 feet elevation in New Mexico.



Copyright 2009 Hells Canyon Journal, Halfway, Oregon. All Rights Reserved. This content, including derivations, may not be stored or distributed in any manner, disseminated, published, broadcast, rewritten or reproduced without express, written consent from SmallTownPapers, Inc.

© 2009 Hells Canyon Journal Halfway, Oregon. All Rights Reserved. This content, including derivations, may not be stored or distributed in any manner, disseminated, published, broadcast, rewritten or reproduced without express, written consent from DAS.

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