Cattle feeders who lose livestock to bovine congestive heart failure (BCHF) know the impact of the disease firsthand. Ready to hear about the latest research on BCHF, feeders and others industry professionals attended a Cattlemen’s College session presented by Kelli Retallick-Riley, president of Angus Genetics Inc. (AGI). The session was held during the 2024 National Cattlemen’s Beef Association’s annual convention and trade show in Orlando, Florida.

While not a veterinarian, Retallick-Riley excels in the field of quantitative genetics and is interested in finding ways to combat BCHF from a genetic perspective. She said research, so far, shows heart health (based on heart scores) is heritable, giving her and her team hope that genetic tools can be developed to reduce risk of the disease in cattle.

Retallick-Riley said she also knows there are other elements outside of genetics, 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. At the same time, the frequency of the disease has been increasing. She said this increase could mean either there really are more cases of BCHF occurring, the industry is getting better at diagnosing it, or a combination of the two factors. Ultimately, the direct cause or causes of BCHF are not yet understood.

Besides the obvious loss of life, what is particularly painful about BCHF is the cattle dying of it inflict a larger economic impact 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.

She shared a few other known pieces to the disease’s puzzle, including a connection to respiratory health.

“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 said.

Researchers have also studied cattle in the complex disease category, meaning they have been treated for at least one other disease. Retallick-Riley said of these cattle, “they 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 and treated for AIP or complex disease without any advantage.

When looking at beef-type cattle, beef x dairy type, versus 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 high to 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.

Looking more at the prevalence of BCHF, from 2017-2019 “less than 1% of cattle placed on feed were dying of this disease,” Retallick-Riley said, and the call to research the disease came about as a grassroots effort among producers.

A consistent theme since that time, as with most research efforts, is the need for quality data.

Relying on records from producers and researchers alike – heart scores, genetic testing and phenotypic data – all continue to be important for better understanding BCHF.

“Animals that are dying of congestive heart failure deaths, those are the ones that never make it to the processing plant,” Retallick-Riley said. “That also means that good data recording in the field is crucial as well.”

When looking at heart scores in particular, preliminary results of current research efforts show a 23% incidence rate of BCHF when hearts score as a 3 or 4. As a reminder, there are no 5s at the packer 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%?”

She said, “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 her team at AGI and partners on the project have thought about developing some type of multi-trait index, but more research is needed to identify the best tools for widespread use.

“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.