The old adage that an ounce of prevention is worth a pound of cure is most definitely true when applied to cattle health programs. We often address disease prevention by discussing vaccination programs (vaccination is the injection of animals with modified or dead disease causing organisms or parts of organisms). But perhaps we should back up one additional step and try to prevent the first stage of many diseases: stress.
Stress is defined as something that alters the normal behavior or function of the animal. Stress comes in many forms including weather (rain, snow and wind), weaning, processing and shipment. Though some stress may be necessary for the production and marketing of cattle, there are steps that can be taken to reduce the impact on the animal.
Why are we so concerned about stress? Well, stress is the starting point for many diseases ? especially those affecting the respiratory tract. When an animal is stressed, its natural immunity is suppressed. This may allow disease organisms that would normally be held at bay to infect the animal. Agood example is the path that leads to respiratory disease. First the animal is stressed. This is often due to a combination of weaning, hauling, processing and marketing. These stresses reduce the calf's ability to ward off infections caused by viruses. The viruses then attack the calf. This is often referred to as the primary infection. This further degrades the calf's immunity allowing yet another "secondary" infection to occur usually caused by bacteria. These often result in pneumonia. It is a long process, but it begins with stress.
There is yet another link between stress and disease. Vaccines are designed to stimulate the "active" immunity of the animal. Under stressful conditions, this process may fail. We have noticed this among calves in our Retained Ownership Program. Calves that were vaccinated against respiratory diseases under minimal stress seem to get sick less often than calves exposed to additional stresses such as weaning, processing or hauling before or during the vaccination process.
How do you avoid stress? Though some stress is unavoidable, most can at least be reduced. One step that is easy to incorporate into management of most herds is to simply vaccinate calves (for respiratory diseases) before they are exposed to the stresses of weaning.
If you plan to retain ownership of calves beyond weaning, we recommend vaccinating for respiratory diseases (such as IBR, BVD, PI3 and BRSV) at least two weeks (one month is better) before weaning. There are vaccines that are safe for calves nursing pregnant cows. Care should be taken to use "killed" or "chemically altered" vaccines that are approved for this purpose. Contact your local veterinarian for advice. At weaning, the calf should be vaccinated once again for these disease agents. This second "booster" is often most effective when a modified live vaccine is used.
Be careful. Modified live vaccines are usually not approved for use in suckling calves, so you must wait until the calf is physically removed from the cow. We have used this procedure at the Headquarters Farm and Coffey Ranch for several years. We have experienced minimal sickness and no death loss with this process.
There are other steps that should be taken to minimize stress. Because weaning is perhaps the most stressful time of the calf's life, try to avoid making it any worse. If you wean in pens, make certain that dust is minimized. Very large pens allow calves to run and stir up dust.You should avoid crowding, but some confinement is desirable to minimize travel. Another option is to wean calves next to their mothers, separated only by electric fence. This prevents nursing but reduces "separation anxiety." This process also allows weaning on pasture where dust is minimized. One cautionary note: you should avoid using most modified live vaccines for respiratory diseases at weaning if calves are weaned near their mothers.
Examine your facilities. Welldesigned corrals and working facilities can vastly reduce stress. Conversely, poorly designed facilities may force you to poke and prod calves, resulting in added stress. Excessive use of electric cattle prods and whips should also be avoided. If you plan to build cattle facilities, research designs in advance. One excellent source is a publication from Oklahoma State University Cooperative Extension Service entitled Modern Corral Design (number E-938). It can be ordered for $5 plus $1 for postage and handling by writing to the following.
Plans & Bldg. Info Service
Biosystems & Ag Engineering Dept.
Oklahoma State University
Stillwater, OK 74078-0469
The bottom line is to carefully assess your total operation. Take steps to reduce stress whenever possible. This should improve the overall health and productivity of your cattle.