Animals can experience stress in all aspects of beef cattle management. Some stressful events are in a producer’s control, and some are not. But in any case, producers should do what they can to minimize stress that can compromise immune systems and make cattle more susceptible to disease.
For example, one of the primary stressors out of a producer’s control is the weather. However, taking steps like providing animals with shelter such as windbreaks or feeding for specific conditions can help minimize the stress caused by adverse weather conditions.
Other stressors can increase the risk for bovine respiratory disease (BRD), or shipping fever, to rise with them. Calving is a stressful event, as is the weaning process. Weaning includes handling and moving calves from their mothers – sometimes into more animal-dense situations. Weaned calves may move hundreds of miles in close quarters to their next production phase and then merge with new penmates.
The opportunity for disease development in this situation is high. And while producers might think the only costs associated with BRD are the up-front, tangible expenses from mortality or antibiotic use, there are many more. In fact, BRD is estimated to cost the U.S. cattle industry $900 million annually.
Prevention is the best medicine
By being aware of what can lead to the increased risk for disease, you can take a proactive approach to managing stress to help prevent or minimize BRD.
Excessive commingling is the greatest risk for BRD proliferating, especially in the fall, when large numbers of calves are being weaned and sold. Calves grouped together at sale barns and moved into feedyards from different operations create exposure to disease – and stress from risk factors including environmental changes, change of diet and social order changes. Even combining calves from multiple pastures on the same ranch to graze after weaning or adding new calves to the mix can lead to greater risk.
If you are moving new calves in, ask about vaccination history. Ideally, calves have had one or two rounds of vaccinations before joining your feedyard or stocker-operator system.
You also can take steps to reduce risk by immediately providing a proper nutrition program that includes plenty of fresh, clean water and a balanced ration with adequate protein, energy and trace minerals given at consistent times. Healthy, well-fed animals can more effectively fend off BRD and will respond better to vaccinations or treatments if they do get sick. When nutrition and water access are optimized, so is the immune function of the calves.
Other management practices that help minimize stress, in addition to all the situations noted above, include:
- Give cattle plenty of bunk space and avoid overcrowding to reduce stress and limit the spread of disease.
- Practice low-stress handling to ensure the moving process goes smoothly for cattle and producers. Low-stress handling techniques include presenting a calm disposition, avoiding loud noises, reducing the use of cattle prods and removing visual distractions.
When introducing new calves into an operation, you should also consider testing for bovine viral diarrhea virus (BVDV). BVDV can cause immunosuppression, and there is always a chance any purchased animals are persistently infected (PI) with BVDV. PI animals can look healthy while shedding BVDV and infecting others. In addition, administering vaccines that effectively prevent the most prevalent BVD subtypes that calves may encounter can reduce the risk of illness.
Similarly, it may be beneficial to administer a dewormer to calves upon arrival. Clinical or subclinical parasitism decreases the animal’s ability to fight BRD and may negatively affect response to vaccination by competing with the immune system for protein and energy.
Make the most of your BRD treatment program
Even with the best herd management protocols in place, animals can still get sick. Identifying signs and diagnosing BRD early, when the animal is on the verge of illness, allows for a better response to antibiotic treatment. Be sure to give the animal sufficient time to respond to the initial antibiotic dose – as administering another dose before advised by the label or your veterinarian increases the treatment cost without increasing effectiveness.
You can also put a precautionary treatment protocol in place for managing the immune system. Metaphylaxis is the treatment of a group of cattle after diagnosis of infection or after clinical disease is found in part of the group. The goal is to prevent spread among animals in close contact that are at risk of disease, including those that may be subclinically infected or incubating BRD. This practice ultimately helps reduce the risk of morbidity and mortality within the group.
If you choose to add metaphylaxis to your management system, it is important to get the timing right and use a broad-spectrum antibiotic that works quickly and has a long duration of activity. Choose an antibiotic that treats BRD associated with Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma bovis, and administer the product according to label directions.
Finally, work with your herd veterinarian to evaluate your current BRD prevention and management program and make adjustments as needed. He or she can help identify ways to minimize stress on your operation and also help you choose the best treatment strategy for when animals do get sick.
References omitted but are available upon request by sending an email to the editor.
