Cost-effective BRD programs require very thorough evaluation and risk assessment of cattle as they come into the feedyard to identify the right antibiotic with the right treatment protocol. Terry Engelken, DVM, MS, associate professor at Iowa State University College of Veterinary Medicine, walks through these critical steps to help veterinarians and their clients achieve an efficacious, cost-effective BRD program.
Q: How do you evaluate calves coming into the feedyard to formulate treatment protocols appropriately?
A: One of the critically important things we struggle with is knowing the cattle’s history when they arrive. Our risk classifications range from high-risk cattle with virtually no history coming out of sale barns, commingled, from a long haul with a lot of stress, to low-risk cattle such as long yearlings coming off grass.
Between those two classifications are medium-risk cattle. If we know a calf has been vaccinated adequately, had parasite control and has been weaned for at least 30 days (preferably 45), that calf typically doesn’t need an antibiotic at arrival but still has the potential to be pulled. Sometimes these cattle can break pretty hard at about three to four weeks on feed.
If you’re dealing with high-risk cattle, it’s hard to argue that metaphylaxis doesn’t pay. Low-risk cattle are just not going to have the pull rates and death loss. But we sometimes struggle with medium-risk cattle. Unless we have consistently seen problems in groups of cattle coming from a particular source, we’re not as likely to utilize metaphylaxis.
Q: Beyond assessing the risk of cattle, what do you consider while making decisions for a BRD treatment program?
A: Other factors to consider are cost and efficacy. It’s not just the cost of the drug, but everything that goes into the health management of those cattle. Making calves comfortable in the first 30 days has a huge impact on how effective our antibiotic treatment program will be. This involves everything from comfortable pen conditions to a good roughage source in the starter ration to get calves up on feed. We need to think about windbreaks, mitigating heat stress, the cattle’s ability to locate the water supply, and water quality. Another critical area is the hospital pen. Is it clean? Is it overcrowded? Animal density that is too high really decreases treatment efficacy. Lots of things impact efficacy of your treatment protocols beyond the antibiotic you select, including training cowboys to find BRD symptoms as early as possible.
Q: How do you balance product efficacy and product return on investment (ROI) while choosing an antibiotic?
A: When we calculate ROI, we typically look at a three-treatment protocol using a front-line antibiotic that’s going to provide a good therapeutic window. We apply the antibiotic cost to the number we expect to treat initially, for the second treatment, for the third treatment, and then estimate the value of the deads. We also want to place a value on chronics, which is hard to do, and depends on your location and your desired benchmarks. For high-risk cattle, I would aim for a 70 percent success rate for first treatment. With low-risk cattle, I’d hope for an 85 percent success rate. Putting a value on the number that die gives us a starting figure to compare antibiotic costs, which helps us understand what kind of increased performance we need from an antibiotic that costs more.
The economic penalty we pay in terms of death loss and treatment costs when considering feeding performance and carcass characteristics gets substantially worse with each treatment. When you look at the Iowa data1, cattle that aren’t treated are worth about $70 more per head than cattle that are treated once, and about $190 more than cattle that are treated two times or more.
Q: How can we better manage BRD?
A: Necropsies are an excellent teaching tool, but are generally underutilized in smaller feedyards. They can reveal why the calf died, the progression of the disease and how good our disease classification was when the calf was originally pulled.
Second, bouncing around in your treatment protocol doesn’t allow you to evaluate the effectiveness of your program because you have calves in a pen treated multiple ways.
A final issue is combination therapies. I haven’t seen anything that shows combination therapies — whether it be two antibiotics at the same time or an antibiotic plus ancillary therapy — to be any more effective than a single-use antibiotic. Combination therapies can increase spending upfront, and don’t necessarily increase return.
1Busby, D. 2010. Tri-State Steer Carcass Futurity Data. Proceedings AABP 2010 Annual Convention, pp 71-81.
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