Associate farm reporter Carli Davenport spoke with Oklahoma State University graduate research assistant Kaylen Stearns, who discussed high altitude disease and bovine congestive heart failure in beef cattle, explaining what causes these conditions, how they are measured, and why they’re becoming more common.
Stearns began by defining high altitude disease as “a non-infectious disease in beef cattle that usually impacts cattle above 5,000 feet of elevation.” She explained that it’s most common in the Mountain West, where “the lack of oxygen at those elevations causes hypertension, which then leads to remodeling of the pulmonary arteries.” As blood flow decreases due to this remodeling, “the animal will then die, and there’s no treatment or cure for this disease.” The only recommendation, she said, is to “take those animals from areas of higher elevations to areas of lower elevation to try to alleviate the stress.”
To help manage the risk of this disease, producers use a PAP score, or pulmonary arterial pressure score. Stearns explained, “PAP scores were invented as a way for producers to help try to mitigate the risk of high altitude disease in their beef cattle herds.” The score “essentially measures the pressure at the pulmonary artery,” determined by “a licensed veterinarian [who] runs a catheter from the jugular all the way to the pulmonary artery and then takes a systolic and diastolic measurement, very similar to human blood pressure.” The measurements are “both measured in millimeters of mercury,” and from those, producers obtain a mean PAP score to guide selection decisions. According to Stearns, “scores will range anywhere from 30 to greater than 50, and the lower scores are more desirable.” She added that “the heritability of this trait is estimated to range from 0.2 to 0.46.”
Shifting focus to bovine congestive heart failure, Stearns noted that this condition is “more found at lower elevations” and “more common in the feed yards.” She described how “the stress from being asked to perform and being pushed on feed causes these animals to experience some stress,” leading again to “an elevation in their blood pressure and hypertension, which then leads to remodeling of their heart.” While it differs from high altitude disease because of the environment, Stearns emphasized their similarity: “When we discuss high altitude disease and bovine congestive heart failure, I do think we’re talking about two sides of a very similar coin.”
Finally, Stearns addressed the rising rates of congestive heart failure in feedlot cattle. She said that “from 2000 to 2012, it was reported they nearly doubled,” and that “mortality rates nearly doubled from 2000 to 2012.” Although researchers don’t have a single clear cause, she pointed to “the push for growth and performance” as a major factor, saying, “we’re pushing these cattle for higher performance, and that does contribute to that increase of bovine congestive heart failure.” She also added, “I think we’re selecting these cattle to perform, so we’re putting more selection pressure on them as well.”
