Systematic Approaches to Biosecurity Investments By: Dr. Jim Lowe, Production Animal Consultation
As producers we all want to minimize the number of new diseases that are introduced in our herd. We use biosecurity practices to accomplish that. Because biosecurity practices often disrupt routine production practices or require significant capital investments there are tradeoffs when making decisions. When constructing a biosecurity system it is critical that a whole-system approach be applied, where biosecurity investments address the most likely routes of disease introduction first. Often the most effective practices (i.e., those that address the most likely routes) are the most expensive or hardest to implement therefore making it tempting to pick the “low hanging fruit” from the biosecurity tree but being frustrated when the rate of new disease introduction is higher than you would expect. I like to think about biosecurity as buying insurance. Developing robust biosecurity systems starts with understanding how likely new diseases are to be introduced and what the most likely routes are. Practically this means that farms in dense regions are more risky than farms in low density regions and need to “buy more insurance”. We can determine the amount of “insurance” you should purchase by estimating the number of times the farm has contact with the “outside world” multiplied by the probability that the pig, thing or person is contaminated with a new infectious disease. Higher density regions mean that pigs, things and people contacting the farm are more likely to be infected. We will use a case example to see how we can apply this idea in practice. 2,500 sow breed-to-wean farm located in a swine-dense region. This farm has a long history of new PRRS outbreaks that has tried multiple things over the years with little impact on the rate of new introduction. Each new PRRS virus costs about $1 million. The owner and the manager have different ideas about the best way to improve biosecurity. The owner wants to build a compost bay as rendering is the biggest issue; the manager wants to build a new load out facility to allow for staged loading. The owner does not buy the truck argument. He pays for the trucks to be washed and disinfected but not dried. He thinks the $300 per truck twice a week is a big investment, but the truck hauls pigs for at least 4 other farms. The manager is not concerned that the rendering is a real issue because they have a good two-sided rendering shed.
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