Cattle feeders who lose livestock to bovine congestive heart failure (BCHF) know the effects of the disease firsthand. Kelli Retallick-Riley, president of Angus Genetics Inc. (AGI), presented the latest research on BCHF Feb. 1, during a Cattlemen’s College session at CattleCon in Orlando, Fla.

She said research, so far, shows heart health (based on heart scores) is heritable, giving her team hope genetic tools can be developed to reduce risk of the disease in cattle.

Retallick-Riley said she also knows there are other elements like management practices and the health of other organs to be considered.

“Because of its low incidence rate, only evaluating cattle dying from the disease is too limiting,” she said. Recent research has focused on identifying animals more prone to BCHF, all while the frequency of the disease has been increasing. Retallick-Riley said this increase could mean there really are more cases of BCHF occurring, the industry is getting better at diagnosing it, or a combination of both. Ultimately, the direct cause or causes of BCHF are not yet understood.

Besides the obvious loss of life, the cattle dying of it inflict a larger economic effect than those lost at earlier stages in life. According to the feedlot studies referenced by Retallick-Riley, affected cattle were dying of BCHF at an average of 110 days on feed, with individual deaths taking place at points across a large swath of the feeding phase.

“When animals were culled and treated for [acute interstitial pneumonia (AIP)], they had a higher probability or a higher rate of succumbing to bovine congestive heart failure,” she added.

Retallick-Riley said cattle in the complex disease category — meaning they have been treated for at least one other disease — also had a higher probability or a higher rate of being called a heart disease death. Without complete information on animals’ health, it is difficult to know if some of these were misdiagnosed.

When looking at beef-type cattle vs. dairy-type cattle and their crosses, she said there are similar ratios, for instance, of disease. Across the board, she and research partners are seeing modest genetic correlations between heart scores and performance traits including hot carcass weight, with little to no correlation to marbling score, in a study presented by Colorado State University.

In a study supported by the Angus Foundation, which included data from 2017 to 2019, it was reported less than 1% of cattle placed on feed were dying of this disease, and the call to research came about as a grassroots effort. Relying on records — heart scores, genetic testing and phenotypic data — continues to be important. 

When looking at heart scores in particular, preliminary results of current research efforts show a 23% incidence rate of heart remodeling when hearts score as a 3 or 4. As a reminder, there are no 5s at the packer included in the recent data collected by AGI, because those hearts have already given out under the pressure of the disease.

When studying this disease, Retallick-Riley said she tries to think of the whole animal as a system rather than just focusing on the heart.

“Heart-score genetic tools could potentially help us reduce the caseload, but I doubt that it’s going to eliminate the disease entirely,” Retallick-Riley said. “Colorado State’s research has preliminary heritability estimates of about 0.28. What about the other 72%? If we put direct selection process on heart score alone, we could create cattle with less heart remodeling. We may also decrease the carcass weight on these cattle based on initial reports.”

Retallick-Riley said AGI and partners have thought about developing a multi-trait index, but more research is needed.

“One of the things that we need to continue to think about is how we’re going to use this at the end of the road, how we’re going to use this to impact production and selection decisions,” she said. 

For more information on BCHF and related research efforts visit https://bit.ly/BCHF-WorkContinues.