So in reality, preventative herd health is simply about identifying and managing risk.
There are far too many risks that can impact on herd health to control them all so we must make a risk assessment that considers the likelihood and potential impact to determine which risks we should concern ourselves with.
A good example of this would be transition cow diseases like milk fever, RFM, metritis or ketosis.
These problems would have a moderate to very high likelihood of occurring if no preventative actions are taken and a moderate impact on herd health and productivity with potentially severe impacts on individual animals.
Based on this risk assessment, it is really simple to justify spending some time, resources and money on preventative actions to manage or mitigate the risks of transition by implementing management like lead feeding, good dry cow management and early lactation monitoring or health interventions.
Often without even knowing it, we make risk assessments and adjust herd management to implement prevention strategies in order to reduce the impact of disease in a proactive way rather than deal with the consequences.
There are other risks that, while they could have catastrophic consequences, the likelihood of them occurring are actually quite low so implementing management or controls is either not necessary or based on individual farmers risk appetite.
In some cases, changes on-farm like increasing herd size, intensification of stocking rate or changing feeding system can significantly change your risk profile for certain animal health diseases from low or very low likelihood to moderate likelihood which makes us change our thinking to implement prevention strategies.
Botulism is a great example of a disease that has the potential to cause significant losses in dairy herds, but the likelihood of it occurring changes depending on management factors that we determine.
In a pasture-based dairy in southern Australia, feeding only hay or small bale silage, the likelihood is quite low, and most farmers unless they are extremely risk averse would be unlikely to implement a preventative vaccination strategy for botulism.
But if they decided to move to pit silage fed out in bulk, the risk would increase and you may consider implementing a vaccine program.
If you decided to purchase a mixer wagon and feed a TMR to the herd, the likelihood of an outbreak is sufficiently high that on a risk/reward basis It would always be my advice that a TMR-fed herd should vaccinate against botulism.
In this example you have a disease where the farm feeding system doesn’t change the consequence but definitely changes the likelihood of the disease occurring, so a good preventative herd health plan takes the changing risk into account and adjusts the management inputs accordingly (by vaccinating) to mitigate the risk.
There are a small number of farms that I work with who have a structured, documented approach to risk management in the form of a risk register that considers individual problems and assesses their likelihood, consequences and what current and future controls are needed to manage that risk.
In a perfect world, our herd health plans for every farm would be so organised and structured but in reality, I struggle to even get written treatment protocols developed, implemented and consistently applied on dairy farms so my dream of risk registers on our farms is probably still a fair way off.
That said, I would definitely encourage all dairy farmers to take a look at their current herd health spend and determine how much of it is preventative and how much is reactive and then to further assess the value and return on their preventative spend.
Preventative herd health is all about determining what the root cause of a problem is rather than just medicating the symptoms and then taking that diagnostic information and determining the risks and management factors that may be contributing to the disease and what preventative strategies we can put in place to prevent future cases.
Talk to your experienced herd health veterinarian for assistance with developing your farm’s herd health plan.
Dr Rob Bonanno is a Prodairy regional veterinary lead based in Gippsland, Victoria.
