Sometimes the best thing we can do for a pen of high-risk cattle is to treat them all, but not always. According to researchers at Purdue University, bovine respiratory disease (BRD) is responsible for half of all cattle deaths from disease in North America. The disease complex costs the beef industry $900 million annually.

With increasing public scrutiny of antibiotic use and the advent of new technologies, John Richeson — Paul Engler Professor of Beef Cattle Feedlot Management at West Texas A&M University — discusses advancements in that space on an episode of Angus at Work.

What is metaphylaxis?

By definition, metaphylaxis is the administration of antimicrobials to a group of animals to control or prevent the spread of infectious disease. In feedlots, metaphylaxis is achieved by vaccinating an incoming group of cattle with an FDA-approved antimicrobial to hopefully prevent or control BRD.

“We would typically do this in cattle that are at higher risk for a BRD outbreak,” explains Richeson. “Because it’s difficult to diagnose this disease — and because we found through research that this practice is so effective — every animal that’s classified as high-risk during initial processing might get an injection of an antimicrobial to control the disease outbreak.”

Another method to achieve the same result may be targeted metaphylaxis, he says. We know not every animal in the group receiving metaphylaxis needs an antimicrobial or will benefit from that antimicrobial treatment. Historically it’s been extremely difficult to know which animals really need treatment for BRD and who might benefit from it.

The targeted approach uses different metrics to evaluate BRD risk at the individual animal level rather than the population level. This judicious use of antimicrobials ensures they remain effective and shows consumers that their concerns for antibiotic and antimicrobial responsibility are being heard.

Regardless, feedlot staff are doing everything in their power to ensure responsibility when it comes to medications, as well as the welfare of the cattle in their care.

“We preserve [metaphylaxis] for what we call higher-risk cattle. Those cattle would be cattle that may have been procured from the auction market system and/or may have traveled a long distance to get to the feedyard or they may be lighter-weight animals,” says Richeson, noting that there are several different traditional metrics used to determine whether cattle are at higher risk for BRD. “We may classify a truckload, a pen or a lot as high-risk and make the decision whether to implement antimicrobial metaphylaxis based on relatively limited information, but we know some information about every set of cattle that we receive.”