Managing Respiratory Disease in Beef Cattle
Recently, USDA NAHMS released a report titled Death Loss in U. S. Cattle and Calves due to Predator and Nonpredator Causes, 2015. The data collected in this report is producer-reported (37,900 operators, report utilizes about 68% of those surveys) and comprises operations from 39 different states. Numbers generated in this report are estimations of true rates. Contained in the document are many interesting facts about our industry that spur thoughts for me. The report is available free-access online at: https://www.aphis.usda.gov/animal_health/nahms/general/downloads/cattle_calves_deathloss_2015.pdf.
The total inventory of adult cattle (defined as greater than 500 pounds liveweight) was 78 million head with an estimated calf crop of 34 million in 2015. Overall, 3.9 million head of cattle and calves were lost in the same year, or 3.5%. When viewed strictly as production units, this estimated death loss equates to $3.87 billion lost to the US cattle industry. This ignores animal and producer welfare concerns, as quantifying these factors is difficult at best. Respiratory disease is the number one killer in both adult cattle and calves in the United States (23.9% of adult losses and 26.9% of calf losses), accounting for nearly $1 billion of the overall industry death loss total cost. Respiratory disease beat out predators, calving-related issues, GI disease, old age, and unknown. A piece of good news is that death loss rates have remained constant since 2000. The bad news is we haven’t been able to overcome the consistency of our losses or drive down that $3.87 billion price tag.
As a cattle veterinarian, this doesn’t surprise me. Bovine respiratory disease is a big deal. I talk about it every day no matter whether I’m talking to a cow-calf producer about vaccines, a stocker operator buying calves out of a sale barn, or a 4-H kid with a new show steer. The moniker of pneumonia looms over much of what we do as modern management strategies and the bovine’s respiratory tract don’t exactly jive. Our animals may experience a plethora of stressors (poor nutrition, weather extremes, calving, weaning, parasites, transport, etc.) that can weaken their immune systems to the point they develop respiratory disease. This stress-induced immune system depression is compounded by exposure to viruses that clear the way for bad-news bacteria to follow closely behind and truly trash the lungs.
Respiratory disease losses haven’t changed because we, as an industry, are essentially at a stand-still on the combat front. As modern-day production practices took off in the 50s and 60s, we also began developing our current day arsenal of vaccines, antibiotics, nutritional schemes, and biosecurity practices. We produce in an environment where we have ready access to pharmaceutical products, knowledgeable professionals, and have the capacity to choose top-notch preventative care for the animals on our farms or ranches. Regardless, we still have not won the war.
On the other side of this argument, the way we have managed respiratory disease for decades could potentially change. Consumers grow increasingly concerned about antibiotic residues in our product and clamor for tighter control of these products’ use in food-producing animals. Additionally, antibiotic resistance is a real and evident threat to the world’s human population, and food animal use of pharmaceuticals is squarely in the crosshairs in our society’s attempt to curb the rise of so-called “superbugs.” Environmental concerns grow stronger over the practice of confining large groups of animals and intensively feeding and growing them. All of these concerns mount up to potential alternative management strategy adoption at best, or regulations at worse.
So, what can we do to proactively manage against respiratory disease in beef cattle? I don’t have much ground-breaking advice. We have to manage the risk of development of disease, rather than managing the disease itself. We can’t change our approximately 3.5% death loss because we have no better tools to treat disease than we have had in the last 20 years. There aren’t new antibiotics or anti-inflammatories coming to market. Worse, the ones we have are showing increasingly lower efficacy in high-risk calves. At a recent veterinary meeting I got to hear a presentation from Dr. Mike Apley, president of the American Association of Bovine Practitioners and a veterinary pharmacologist. He discussed antibiotic resistance in respiratory pathogens of beef calves in Kansas feedlots. In the graphics he presented, there was an obvious trend towards increasing levels of resistance against the most widely used products over the past 5 to 10 years. In some cases, the development of resistance was exponential. This is alarming to me, and indicates that we need to focus our attention towards more reserved use of the products we have.
In the most recent newsletter from the American Association of Bovine Practitioners, one of the highlighted publications for beef veterinarians was a paper comparing treatment of ultra-high risk calves with one commercial antibiotic on arrival to a feedlot versus two commercial antibiotics at the same time. The conclusion provided was two is better than one because this treatment decreased morbidity by 50%. This means half as many calves got sick as did in the untreated group. Note that calves still got sick even if they got two antibiotics at the same time! It is this group of animals that will have death loss, regardless of what we do. As I read this abstract, I had to shake my head – here is the problem highlighted perfectly. We are led towards thinking about those animals most at risk and turning them around, even if only by percentages. While I understand the logic, economics, and realities, and am not so idealistic to think it should or should not be this way, I must advocate here for better.
What is the best way to decrease morbidity from respiratory disease? Preventative health. We have to get cattle owners to become cattle managers, and get them invested in doing more for their cattle and our industry. We have preached preconditioning calves prior to sale off the farm for the last decade, and calf buyers pay top dollar to get those calves. Preconditioning is the single most value-adding, welfare-protecting, and risk-mitigating practice a producer can adopt. We have to do better than only 60% of operations vaccinating at least some animals on the farm or ranch, as was reported in the 2008 NAHMS report. Beyond simple management strategies like these, we must focus on holistic management practices, as advocated by Beef Quality Assurance programs, across the entire herd. Practices that provide consistent balanced nutrition to cows, limit the effects of environmental stressors, and balance genetic selection to get better health and resilience into our stock are of utmost importance.
The answer is not in a bottle. We, as a wide-based, relatively small-scale producing community, must recognize this fact and commit to changing practices. Maybe one day we will decrease respiratory disease’s effects on our industry through identifying genetic markers that predispose cattle to disease or discover a non-antibiotic based therapy for eliminating morbidity and mortality in feedlots, but right now, that is still science fiction. Today we have to recognize that the demands of our beef production chain present significant challenges to the health and well-being of our high input and high output brand of cattle. To meet those challenges, we need to be meticulous in our management and focus on setting up animals for success. Work with your veterinarian to identify opportunities in your herd to improve by setting up preventative health plans, biosecurity protocols, and proactive management of marginal animals. When sickness occurs, seek medical consultation sooner rather than later. Veterinary examination should be a first response rather than a last resort. Commit to only using antibiotics when animals have a reasonable chance of improving, and hold your veterinarian to the same standard.