Innovations in Bovine Respiratory Disease prediction
Researchers use new technology to target treatment
By Laura Nelson
It’s deadly. It’s costly. And we haven’t made significant progress in fighting its effects in nearly a half-century of battle.
“BRD is still the 800-pound gorilla in the room as far as disease and animal health in the feedlot is concerned,” West Texas A&M University animal scientist John T. Richeson says. Richeson is a member of the university’s Feedlot Research Group with a focus on the relationship of management, nutrition, physiological stress and immunomodulation — interventions aimed at modifying the immune response — on bovine respiratory disease, or BRD, in cattle.
According to Richeson, the respiratory disease is responsible for about 80% of all morbidity and more than half of all mortality in the feedlot industry. A July 2020 research paper from Oklahoma State University tagged feedlot and stocker backgrounding death loss due to BRD alone at a $274.84 million economic loss. The total annual loss due to BRD, including treatment costs, reduced performance, reduced carcass value and death loss, has been estimated to be nearly $1 billion.
“We’ve been fighting this disease for more than 50 years, and it’s still the most prevalent and economically impactful disease we face,” Richeson says. “The BRD mortality rate is the same today as it was 30 years ago.”
Research and evolving technology surrounding early diagnosis and treatment of the disease holds promise, but it still doesn’t address a key factor in its cause: stress due to marketing, movement and co-mingling young animals.
“Everybody is cautious to lay blame on the system itself because it’s the system we have. And it’s a big, complicated system that is difficult to change,” Richeson says. In a 2015 research paper, Richeson and Samuel Ives noted there is an average of 15 middlemen between the rancher and the consumer.
In a July 2020 paper published in Veterinary Clinics of North America: Food Animal Practice, Oklahoma State University economist Derrell Peel noted the general movement of cattle from small cow-calf herds dispersed across the country to large, geographically concentrated feedlots “implies much assembly, sorting, commingling and shipping of cattle. Thus, the stressors associated with BRD are an integral and inevitable component of beef cattle production.”
The same paper noted feedlots were spending an excess of $75 million annually on BRD treatments. Nearly 60% of all feedlots use metaphylaxis — mass medication on an arrival group in advance of an expected outbreak — to prevent respiratory disease, particularly on lighter, higher-risk cattle.
The success of preventative metaphylaxis has continued to offer economic incentive for feeders to purchase high-risk cattle at a lower price which, in effect, may continue to disincentivize shifts to proven disease preventative measures at the cow-calf level.
None of these systematic issues have changed over the past several decades, which may start to explain why the prevalence and negative economic impact to the larger industry has remained unmoved, Richeson says. What has changed, he notes, is consumer perception and regulatory tolerance for antimicrobial use in food animals.
That increased scrutiny, Ives and Richeson wrote, may cause feedlot producers to consider more judicious, targeted use of antimicrobials, particularly when it comes to metaphylactic use.
Use tech to target
“If you’re able to predict BRD risk of individuals, you could target metaphylaxis at processing — instead of every animal receiving treatment on arrival, you target or select particular animals that the technology suggests are at greater risk,” he says.
Research at the West Texas A&M Research Feedlot indicates about half of high-risk cattle are shown to have abnormal status at arrival or greater risk of becoming sick.
“Successful targeted metaphylaxis would mean you then decrease your antimicrobial use and costs by about 50%, because you’re not medicating animals that don’t need it,” Richeson says.
The university is in the midst of several years of research and trials with Advanced Animal Diagnostics, Inc., a North Carolina-based company testing chute-side blood tests that indicate varying blood leukocyte — white blood cell — differentials. White blood cell counts provide an early indicator of stress and disease, which indicates animals with compromised immune systems before any visual signs of BRD appear.
The company uses its QScout Cattle Lab technology to read and indicate the animals’ immune system status in approximately 35 seconds, based on a small jugular blood sample. Results measure comparable blood leukocyte levels based on an evolving algorithm calculating healthy levels in similar cattle. The more data they’re able to input into the algorithm, including data on the animals’ weight, region, risk factors, etc., the more accurate the algorithm becomes.
The technology is not yet commercially available, but trial data, according to the company, indicates using the QScout blood diagnosis to target metaphylactic treatment resulted in an 86.6% reduction of antibiotic use on arrival with no difference in hot carcass weight, yield grade, quality grade or death loss.
“There’s also potential then to sort cattle and manage cattle differently based on the indicated risk,” Richeson explains, potentially reducing transmittal to otherwise healthy calves.
New tools to be tested
Richeson adds researchers continue to explore other possibilities for early BRD prediction, too. His research team will explore the potential to train and use dogs to predict illness in calves at processing based on breath odor. Dogs have already been shown to detect low blood sugar, cervical cancer and other diseases in humans.
“It may be as simple as the trained dog walks to the chute, sniffs a calf’s nose and offers a signal if it detects a particular odor associated with BRD outcome,” Richeson says.
Their team is also interested in research using microbiome signatures or facial recognition and artificial intelligence. Again, this technology would be built on algorithms dependent on hundreds of thousands of data points. In this case, those data points would be photos of animals’ faces.
“There are things we can’t notice with the human eye, but Artificial Intelligence may differentiate an eye with a slight droop or an ear at a different angle or other facial features that could indicate health risk,” Richeson notes.
These high-tech tools could be layered on to existing, proven indicators of an animal’s propensity to sickness: a calf with a ranch tag in his ear at arrival to the feedlot had a 50% lower change of morbidity than one without; bulls are more than three times more prone to get BRD than steers; and lighter calves are more likely to get sick than their heavier, lower-risk counterparts.
“Whether it’s as complicated as a microbiome fingerprint or blood test or as simple as noticing a ranch tag during processing, we can incorporate this information together to help us better predict illness and target treatment,” Richeson notes.
He calls that a win-win-win against a problem which has persisted for decades — lower costs and increased animal welfare at the feedlot, the ability to demonstrate to consumers and regulatory agencies the judicious use of antimicrobials in beef production is a priority and reduced resistance to current antimicrobials.
“If the technology truly improves prediction or sensitivity and specificity of BRD diagnosis, and we can reduce and refine the overall antimicrobial use, it should reduce the amount of antimicrobial resistance that is occurring, which is certainly a concern with consumers, but it should be a concern for the cattle industry, too,” Richeson concludes. “If we can reduce antimicrobial resistance, we allow our existing drugs to remain effective for as long as possible.”
This story originally appeared in the September 2020 issue of The Cattleman magazine, Texas and Southwestern Cattle Raisers Association’s flagship publication. Join today to start your subscription.