By Phil Durst
The Swiss cheese layer biosecurity concept was a new addition to the biosecurity talk in the Beef Quality Assurance curriculum. Though I’ve taught biosecurity many times, the graphic of Swiss cheese slices puzzled me initially. Slowly, I began to understand that each protection we provide livestock is like a slice of Swiss cheese; it has holes, or weaknesses, in it. That is, no one layer (slice) provides perfect protection. However, as we add more layers of protection, like more slices of Swiss cheese, each one has strengths in some areas and holes in others, but the cumulative effect is that more of the holes are covered, and protection is therefore stronger.
The importance of the point was driven home during a conversation with my son, a pilot with a major airline. We talked about a recent tragedy involving a passenger plane at an airport. It is the kind of conversation that I don’t like having with him because it reminds me of the risks he faces. In this case, I said that I understood there were several factors at play in the accident. He agreed, saying that a lot of things went wrong.
It was his next statement that made everything fall into place. He asked me, “Have you ever heard of the Swiss cheese principle?” Wow, in an instant, I saw the Swiss cheese illustration applied to security in many areas, from the safety of passengers on a plane to the health of cattle in the field.
The goal is the same. No matter what the threat, the principle of protection remains constant: any one action may or may not work all the time, but when we add layers, when we do more than one thing, the degree of security grows. The figure from the BQA program shows that principle in action for scours defense in the protection of the calf, but it could be used for anything that needs to be protected.
Some of the first defensive layers named in the illustration are colostrum intake, maternal nutrition and maternal vaccination. Those are interrelated; that is, the latter two impact colostrum quality and when a calf gets good colostrum intake, it has a major impact on protecting the calf’s health. However, since we don’t always know the colostrum quality or how much colostrum the calf received, we had better make sure we also have other layers of protection.
Source : msu.edu