Producers are advised to talk with a veterinarian once a year about vaccination programs to get the best results
RED DEER — There are different kinds of vaccines on the market and it is important that producers know what their cattle have received in the past.
“It is really important to know the history of animals and what they have had in their lives when you are vaccinating mature animals,” said veterinarian Craig Dorin of Veterinary Agri-Health Services in Airdrie, Alta., who presented practical vaccination information for cow-calf producers at the recent Alberta Beef Industry Conference held in Red Deer.
He recommended that producers talk with a veterinarian once a year about vaccination programs to get the best results.
It is important to understand the pros and cons of killed and modified live vaccines, he said.
Killed or inactivated vaccines contain all or part of a dead pathogen. They do not replicate. One dose of a killed vaccine does not generate strong immunity so two doses are needed to get an immune memory response and build antibody levels high enough for protection.
Modified or attenuated live vaccine has a live pathogen that multiplies in the body but has been modified or weakened so it no longer causes disease.
Modified live vaccines need to be used with caution around pregnant animals because they will replicate and could sicken animals or cause abortions.
When using a modified live vaccine, make sure it is given every 12 months. If there is a greater lag in delivery, the product is not effective.
Give a modified live vaccine three to four weeks before turnout in the spring so it does not upset the estrus cycle.
Vaccination of calves depends on the situation, pathogen, animal and environment.
Calves receive their first line of protection from the maternal antibodies found in colostrum but over time those disappear.
Calves that did not receive enough maternal antibodies could be vaccinated as young as three days old for added protection. However, a vaccine given to those with adequate maternal protection may not be effective.
In the real world, the level of maternal antibodies is unknown, said researcher Claire Windeyer of the University of Calgary’s faculty of veterinary medicine.
“We don’t generally know what levels of maternal antibodies are in our calves so we are going to have to design that program based on our herd history,” she said.
Calves can receive intranasal vaccine and develop localized mucosal immunity early on in life.
“We know that mucosal immunity isn’t blocked by maternal antibodies,” she said.
Injectable vaccines later on at pre-weaning or weaning can elicit an immune response.
“Injectable vaccines are unlikely to protect our young calves if they have high maternal antibodies, but if maternal antibodies are low or when they become low, our injectable vaccines tend to work,” she said.
The three Ps of vaccination to guide a program are pathogen, product and production group.
Producers should consider the following points:
- What diseases usually present problems and when do they occur?
- What is the herd’s risk level? Are the cattle commingled or are they going to a community pasture where they can be exposed to different diseases?
- Is it an open or closed herd?
- What pathogens are threats in the area?
- Is there a marketing advantage in vaccinating calves? If cattle are on a good vaccination program, potential sellers and buyers should know this. There is probably no extra money but buyers may be more inclined to bid on the vaccinated cattle.
“Research shows cattle with health problems also have performance and grading problems,” Dorin said.
Pathogens can be categorized into groups and that determines which vaccinations are used.
- Respiratory diseases may be bacterial or viral. The bacteria may be pasteurella, mannheimia or histophilus. Viruses are connected to bovine viral disease or infectious bovine rhinotracheitis.
- Reproductive diseases could be BVD, vibrio or leptosporosis.
- Clostridial diseases can be handled with seven- or eight-way vaccinations. These include blackleg, malignant edema, diarrhea and pulpy kidney. They may or may not have tetanus included in the product. If castrating older calves, consider using tetanus in the vaccine program.
- Scours viruses include roto and corona viruses, E. coli or sometimes C. difficile.
- Miscellaneous diseases include issues like pinkeye, foot rot and anthrax.
Combination vaccinations may include a number of pathogens.
It is also important to check product labels for fetal protection in regard to BVD. This is an immuno suppressant disease that may cause respiratory disease or abortions.
It also creates persistently infected (PI) calves that were infected during 60 to 90 days of gestation. The virus becomes part of the calf’s genetic makeup and the calf does not mount a defence against it. The PI calf sheds virus throughout its life and infects others.
PI animals have poor health and when they enter the feedlot they may infect pen mates because they are shedding the virus.
“When we are using modified live vaccine in cows we are always using a product that is labelled FP,” said Dorin.
Products have different routes of administration so they may be given via the intramuscular, subcutaneous, intranasal or oral method.
Not everyone reads the product label but there are a few key words that are important, said Windeyer.
Producers should look for:
- Aid in disease control. The drug company has to show it reduces the severity, duration or onset of disease. It does not mean it will keep the animal from getting sick.
- Aid in prevention of disease fits most bovine vaccinations.
- “Prevents disease” indicates an 80 percent reduction in the incidence of disease.
- “Prevention of infection” is not a common label.
“Vaccines are not 100 percent protective. They are part of an animal having a better immune response that does get exposed. They are not a magic bullet,” she said.
Production groups have different needs when considering vaccines.
Calf-hood vaccinations should consider:
- Age and presence of maternal antibodies in calves.
- When the calf-hood disease is evident.
- What are the primary diseases observed?
- When are calves handled so vaccines can be administered?
- What is the goal of vaccination?
- How are calves being weaned and marketed?
A three-way intranasal vaccine gives mucosal immunity in young calves that can reduce viruses like pneumonia. There is also an intranasal bacterial vaccine against mannheimia or pasteurella that can be given early on. Consult with a veterinarian about the best time to administer these to young animals.
There has been a shift in vaccine protocols to combine an intranasal with injectable to give calves all the antigens they need. Mucosal immunity does not last long so give it again six weeks later.
The vaccine program should be timed to offer immunity when the calf is best able to respond.
‘These diseases have different time periods when they respond,” Dorin said.
Mannheimia haemolytica is the main bacteria responsible for pneumonia and shipping fever in calves.
“The time lag from vaccination to immune response is about 10 days,” he said.
The calves are treated with antibiotics until the vaccine kicks in, but these products do not work as well as they once did.
When vaccinating heifer replacements, consider what they received as calves. Know what diseases are in the herd and try to set up heifers to have good immunity when their calves are born. They should be vaccinated for scours.
Follow the label for scours vaccine as to when to give the initial priming dose followed by the booster dose to get an adequate response. Producers want to make sure the antibody buildup matches when calves are born.
“If there is an extended calving season it can be a long time between immunity,” said Windeyer.
“If you have got a scours problem, you may have to run the late calvers through a second time to rebuild protection and make sure it is present in colostrum.”
It is also a good idea to know what is causing the scours so the vaccines can be matched to the pathogen. However, diagnoses can be inconclusive.
Talk with a veterinarian to make sure the vaccination program matches with the management program.
A fall vaccination program works but the timing of the immune response may be better aligned with a pre-breeding program. However this may not be practical.
“In our world, it doesn’t matter whether you are on a killed or modified live program,” said Dorin.
“All our breeding heifers would get a pre-breeding five-way viral. The vibrio and lepto are producer dependent,” Dorin said.
If those reproduction diseases were not present, the animals would not receive them.
Among mature animals, bulls should be boostered every year.
Give bulls vaccines three to four weeks before turnout but in practical terms many producers may prefer to do it at semen check time.