BRD: Are We Fighting the Wrong Battle?

John Maday, Editor, Bovine Veterinarian ( Lori Hays )

The beef-production system in the United States has evolved to capture efficiencies and capitalize on the ruminant’s ability to turn forage into high-quality protein. At the same time, the high cost of grazing land and segmentation of production sectors prevents the levels of integration dominating the pork and poultry industries.

These and other factors have created a system in which calves weaned on a small farm in the East or Midwest are marketed through a sale barn, co-mingled at an order-buyer’s facility, shipped to a stocker or backgrounder facility on the Southern Plains, co-mingled again and grown for a few months before shipping to a feedlot in another state for finishing. Or, in many cases, the weaned calves skip the transition phase and ship directly to a feedlot halfway across the country. At each stage, owners work to add weight and value, hoping to earn a profit selling the cattle into the next production stage.

In spite of its complexity, the system works well in most respects, with one major weakness: It favors establishment of infectious diseases, particularly bovine respiratory disease (BRD). That weakness presents most visibly when calf buyers see profit opportunities in lightweight, freshly weaned calves of unknown health background. Buyers know that if the price is right, they can “straighten them out” by investing in health care, while accepting higher levels of morbidity and mortality and capitalizing on compensatory gains.

Cow-calf producers, in many cases, do not believe the market will reward them sufficiently to pay for proven preconditioning programs and extended weaning of 45 days or more. So they take what they can get for the “high-risk” calves.

During the recent 2019 BRD Symposium in Denver, several presenters made reference to the epidemiologic triad or triangle model for infectious disease. In this model, according to the World Health Organization, disease results from the interaction between the agent (pathogen) and the susceptible host, in an environment that supports transmission of the agent from a source to that host. Presenters repeated a suggestion that the industry, in its continuous battle with BRD, has focused too much on the pathogens. At the stocker/backgrounder/feedlot level, mass medication and individual treatments remain the primary focus in managing against respiratory disease.

We could be more successful if we shifted more focus to the animals, and the environments where they are raised. Mississippi State University veterinarian David Smith, DVM, PhD, promoted adoption of a systems approach, considering all the factors involved in BRD prevalence, such as cow nutrition, cow vaccinations and calf vaccinations back at the ranch, while building in better economic signals to reward practices that minimize risk to the buyer.

Referring to the disease triad, Smith stressed that a systems approach would consider issues associated with controlling BRD pathogens, while also dedicating at least equal attention to the animal – its nutrition, microbiome, stress levels and overall immune system and – and the environment in which it is raised, marketed and finished. The pathogens will always be present, and we should continue developing better ways to reduce exposure and effectively treat sick animals. However, management practices beginning at the cow-calf level and throughout an animal’s life could minimize the ability of those BRD pathogens to cause disease.

The concepts of emphasizing disease prevention and linking herd-health practices with cattle values are not new, but the need to demonstrate progress in antibiotic stewardship while also reducing cattle morbidity ramps up the urgency for action. This shift would require a broad-based industry effort to fundamentally change our current beef production and marketing structure, with birth-to-slaughter traceability a key component. Traceability could, over time, facilitate an evolution of market signals to provide greater incentives for cow-calf producers to ship healthy calves with immune systems prepared for the challenges ahead.