Veterinarian discusses bovine vaccination recommendations and timeline
Newborn calves gain a temporary and passive immunity against disease when they ingest colostrum from the dam – since this “first milk” contains maternal antibodies.
After a few weeks or months this temporary protection begins to wane and calves must build their own immunities.
Vaccinating calves at the proper time can help protect them until weaning age. Vaccinating too soon, however, may not stimulate much immune response. If the calf still has maternal antibodies in their system, these tend to interfere with building its own immunities.
Thus, the big question is when to vaccinate and with what for optimum immune response in the calf. Dr. Steve Hendrick, Coaldale Veterinary Clinic, Coaldale, Alberta, says ranchers should always discuss a herd health program with their own veterinarian, but there are some general guidelines which may be helpful.
“Vaccination is a way to have controlled disease exposure,” explains Hendrick. “We don’t want our animals to have to go through natural disease conditions, so if we can give them a little exposure to a weaker strain, or a controlled exposure, they are better off than having to fight off a more severe natural infection.”
“It is recommended calves be boosted before they leave the farm, so they would stay healthy for the next owner or feedlot, but even getting one dose into them would do a lot for our industry,” he says. “Veterinarians advise most clients to use a Bovine Viral Disease (BVD) vaccine, and it’s usually a five-way modified live virus vaccine. This, along with a clostridial vaccine, is probably the most important recommendation for calves.”
There are several additional vaccines important for calves in certain regions.
“On ranches having a lot of summer pneumonia, some veterinarians advocate the use of a vaccine against Mannheimia, otherwise known as Pasteurella haemolytica or Histophilosis,” explains Hendrick. “I routinely recommend this for herds having problems with these bacterial infections. If a herd has had a problem in the past, it’s probably a good idea to add this vaccine to prevent problems in the future.”
Some pathogens can cause pneumonia, so if calves are vaccinated at branding age the vaccination they receive at weaning time acts as a booster. Some ranchers don’t vaccinate at weaning. They simply sell the calves and don’t feel they would benefit from the expense since they are not getting paid for the extra cost and work, he notes.
“For replacement heifers, however, or any calves producers might be keeping over winter, it is important to vaccinate at weaning age, to gain the benefit from protection,” he says.
Timing of vaccinations
The big debate is when to give the vaccinations.
“Most of my clients are still vaccinating calves at about one to two months of age, when they are branded. Some herds experience disease in calves earlier and may need to work with their veterinarian to decide whether to vaccinate calves sooner, maybe using an intranasal product,” he says. “Producers who have purebred herds calving early and put pairs through a calving barn are more likely to use intranasal vaccines at birth.”
“In some situations, where calves are born later in the season out on grass – in May and June – ranchers found it was so hot and dry in July when they brought them in for vaccinating, we started vaccinating those calves at birth instead. The stress of trying to vaccinate in July was too much,” he says.
There are challenges when gathering cattle off grass and putting them through a dusty corral with the stress of sorting and vaccinating, which might seem to defeat the process. Some herds now receive vaccinations at birth.
“This isn’t ideal, and it wouldn’t be my first choice. But faced with whether to vaccinate at birth or not giving any vaccines, we chose to vaccinate the calves at birth, and I can’t honestly say we’ve had worse results. We don’t know whether this means the calves didn’t have enough of a challenge these last few years, or the vaccine is helping,” he notes.
He also talked to some of the drug company technical services veterinarians about using clostridial vaccines early.
“Even though it says on the label to not give this before one month of age, we haven’t seen any problems with giving the vaccine to very young calves. We also haven’t lost calves to blackleg or some of the other common clostridial diseases, so I feel comfortable giving clostridial vaccination at birth, as well. These cowherds have been vaccinated and given a booster on a regular basis, so their calves may also be getting good protection, at least temporarily from colostrum,” says Hendrick.
The best age for giving BVD and Infectious Bovine Rhinotracheitis (IBR) vaccines is still debatable.
“From what I’ve seen in the literature, if producers vaccinate calves with high levels of maternal antibodies from colostrum, the thought has always been those antibodies will mop up the antigen in the vaccine and the animal won’t develop a good response,” says Hendrick.
There are two types of immunity.
“One is cell-mediated. There are some non-specific immune cells just cleaning up whatever foreign material they see,” Hendrick explains. “This is the first part of the immune system to develop and is very important for most of the diseases a calf faces.”
“We believe there is probably an increase in this type of immunity with early vaccination, even though we might not see much increase in titers or antibody response which is more secondary,” he continues. “We feel if these calves do get exposed to the disease, they at least have good cell-mediated immunity from the early vaccination. We feel this is very important for some of the viral infections. This is why I feel ok about switching some herds to vaccinating at a younger age. If calves are being branded at a later age, I still recommend vaccinating at branding time,” he says.
It is important to work with a local herd health veterinarian and come up with a plan based on what has worked in the past for a producer’s specific herd and what diseases they may have, he notes.
“We see some baby calf pneumonia which probably isn’t Pasteurella. It’s probably Bovine Respiratory Syncytial Virus (BRSV) or some other virus, rather than bacterial,” he shares.
If producers work with their veterinarian and make a diagnosis, they can be more specific about which vaccine they choose, he explains.
There is an intranasal viral vaccine, and it may work in some herds. It stimulates local immunity in the nasal passages, where the virus would normally enter.
“Producers are basically stopping this entry, or minimizing the viruses’ ability to get into the body and set up infection. It’s almost one step earlier than giving vaccine under the skin, to be absorbed by the body. In this scenario, the virus gets into the nose and goes on into the body before the generalized immune response can attack the virus,” he says.
“Some ranchers say the intranasal vaccine has worked very well for them, and others have used it and didn’t think it helped much,” says Hendrick. “I think it depends on what the calves are exposed to. If the disease is bacterial rather than viral, the viral product won’t help.”
The intranasal vaccines won’t cover all the diseases causing problems. Producers have to know their enemy to choose the right weapon.
This is why producers need to work with their veterinarian and get some diagnostics on what is causing disease in the herd. They will be better able to select the appropriate vaccines, rather than just using what the neighbor uses or what is read about for certain products.
Heather Smith Thomas is a corresponding writer for the Wyoming Livestock Roundup. Send comments on this article to roundup@ wylr.net.