Speaking at the Teagasc Green Acres Calf to Beef Programme farm walk – which was held in Co. Kilkenny recently – MSD Animal Health veterinary advisor, Sarah Campbell, explained the importance of vaccination as part of a herd health plan.
She said: “Animal health is a delicate balance between the level of immunity and the burden of challenge on a particular farm – from various different pathogens that can possibly cause disease.
“How farmers use vaccines is also very important, so when we think of the different types of vaccines, for example, live or inactivated vaccines, it really does depend on how we actually use those vaccines.
“Live vaccines are very useful; they mimic natural infection very well and, therefore, usually one dose of a live vaccination is sufficient.
“However, inactivated vaccines are very different on how they challenge the immune system and really the second dose of the primary course is so important,” she added.
“The first dose is often the priming shot and then the second dose – followed up four-to-six weeks later depending on the schedule of that particular vaccine – is the actual dose that will provide the immunity for the six months or year depending on which vaccine you are using.”
Route of administration and timing
Sarah noted that the route and timing of administration is also very important.
“If a vaccine is to be administrated intranasally or intramuscularly or subcutaneously, then the product protocols should be followed,” she said.
“The timing of vaccination is very important so, ideally, the primary course or the booster dose should be administered prior to the next risk period in order to benefit from a maximum immune response, and to provide protection.
“There’s often a lot of environmental factors that can influence animal health, so it’s important to look at the housing, hygiene and bio-security within an animal population, and making sure all animals in the population have received the vaccine in order to benefit,” Sarah highlighted.
What diseases?
Touching on some diseases which can pose problems on dairy calf-to-beef farms, Sarah said: “In young calves up to one month-of-age, we know that diarrhoea is the biggest cause of mortality in this age group.
“Therefore, it is very important that the dam has been vaccinated against calf diarrhoea so that, when it is born, it will benefit from those antibodies in colostrum.
“From one month old onwards, bovine respiratory disease (BRD) or pneumonia is the biggest cause of mortality; therefore, it is very important that we protect against bugs that cause pneumonia.
“Those bugs – we’re thinking viral agents such as PI3, BRSV, and occasionally IBR, and in terms of bacteria – we’re thinking of pasteurella pneumonia; so it’s very important we get those primary courses completed – especially before weaning because we know weaning is a big risk period and a big source of stress on calves,” she concluded.