What Vaccines do My Weaned Calves Need and When Should I Give Them?

It always seems like a lot of work at the time, yet it sure is nice to see that pen of calves at the bunk after they are weaned and settled in. All that work bringing them to this point makes the sight of them as a group of feeder steers look real pretty. However, it isn’t pretty if disease breaks in that pen. To avert this catastrophe, we utilize vaccines that prep the immune system to ward off pneumonia and other diseases following weaning. Many producers question which vaccines they should use and when is the best time to give them.

The no-vaccine window
Without a doubt, the best time to administer a vaccine is at least three weeks before weaning. The calf is less stressed, allowing the immune system to mount a better response to the vaccine. Building this immune response takes time (at least three weeks for the full benefit), hence giving the vaccine in advance allows the calf to be fully prepared to ward off disease at the most stressful time in his life—weaning.

If administering vaccine isn’t possible before weaning, there are two other periods when it is best. The first is within three days of weaning, the second at least thirty days after weaning. The reason for this window where we do not want to vaccinate has to do with calf psychology. Weaning is a period where calves must learn a new way to live away from the cow. That first month, they settle into their new pen and establish a pecking order within that herd. They also learn how to eat and are being stepped up on feed through this period. How they acclimate in this time is the single most important factor in determining their future outcome.

If we vaccinate at the start of this period, we don’t harm this acclimation because the stress of handling is before the acclimation. If we wait thirty days, when the calves return to the pen after processing, they already have an established order and regimen they fall back into. However, if we interrupt the process by working these calves between three and thirty days post-weaning, we upset their applecart before they’ve figured out how to organize their apples. Add to this that we’re pushing them up on feed through this period, and they may go off feed for a day, then come back to a diet too starchy for them. This leads to digestive upset, which can trigger respiratory disease.

What vaccines to give
Respiratory disease is the number one issue we are vaccinating for at processing. While it occurs most frequently in the first three weeks after weaning, hence the incentive to vaccinate on the cow, it flares up later in the feeding period as well. While other diseases occur, such as Overeating disease, most of our vaccination efforts are focused on the viruses and bacteria that cause pneumonia.

The two core vaccines for pneumonia are the five-way viral and a Mannheimia (formerly known as Pasteurella) vaccine. The five-way covers Infectious Bovine Rhinotracheitis, Bovine Respiratory Syncytial Virus, Bovine Viral Diarrhea Type I and II, and Parainfluenza 3. These are five common sources of respiratory infection. Mannheimia is the most common source of bacterial pneumonia. These viruses and the bacteria are so commonly found together in bovine pneumonia cases that it is recommended that every calf is vaccinated against them.

In addition, a seven-way Clostridial is part of the core vaccine program. One dose is typically sufficient for the prevention of Blackleg and aids in the prevention of Overeating disease.

In certain situations, a booster dose may be of aid. If a producer experiences significant issues with other pathogens, other vaccines can be added to the protocol. Another species of Pasteurella bacteria called Pasteurella multocida is a common addition for certain herds. Mycoplasma vaccines may be of use; however, we are not certain enough of their efficacy to recommend them routinely. Other diseases outside of pneumonia may be abated through vaccine. Yet, it is best to converse with your veterinarian before making that decision, as adding a vaccine increases cost and stress on the calf. If it will not be of benefit, do not use it.

Simply injecting vaccine into a calf does not equate to immunity. Rather, the environment the calf is weaned from and into determines the success of weaning. While vaccines play an important role in this, they are not a silver bullet. Therefore, take care to administer them at the appropriate times to enhance immunity and focus on creating a comfortable pen where the calf resides. Doing so will be the best chance to give you that delightful pen of  calves to gaze across when you run the feed wagon in the morning.