One of the most overlooked breeches in biosecurity occurs when show animals are returned to the farm and not quarantined.
Since this animal is not a new purchase and appears healthy, producers might overlook this risk. Taking pregnant animals to
shows has the added risk of introducing BVD that a quarantine period will not eliminate. Testing for diseases or purchasing
from herds certified for certain diseases is prudent when obtainable. Finally, nothing takes the place of good sanitation
on the farm, especially when it comes to preventing calf diseases.
Controlling people and vehicle movements
This area is where many of us tend to get lax in our recommendations. However, there are many examples of disease entering
a farm on a person or vehicle, so recommendations to prevent this are important. Securing the farm perimeter is a prudent
move for several reasons, not just for preventing entry of disease. Fences should be maintained to keep the farm's animals
in and other animals out. Deer can pose a biosecurity risk, but keeping them out usually is cost prohibitive. Although expensive,
double fencing between neighboring farms should be considered to prevent spread of disease through aerosol or direct contact.
This might not control vector-borne transmission, which is difficult and usually vector-specific. Gates should be locked to
prevent people and vehicles from gaining access without permission. Delivery trucks should have limited access to the farm
and travel and park on paved or rocked surfaces. These areas are more likely to stay dry and have direct exposure to sunlight,
which help decrease pathogen loads.
With much of the population unfamiliar with agricultural practices, we should encourage visitors to livestock operations.
However, some precautions should be taken. All visitors should sign a registry and be escorted on visits. Non-agriculture
visitor groups, especially youth groups, are unlikely to bring a disease onto the farm, but they are at risk of leaving with
a potentially zoonotic disease. They should be advised to "look but not touch" and have a place to wash their hands following
a farm tour. Visitors from other farms, particularly international visitors, are a bigger biosecurity risk. Provide disposable
boots, and don't allow direct contact with animals. This works fine for visitors but might insult friends and family who come
to help. Producers should still ask that they come with clean boots and clothes, and promise to do the same when they return
the favor of helping out. Providing water, disinfectant and a brush will allow helpers to wash before they return home to
their own farms.
Producers tend to focus on specific diseases, but we know that many of the diseases we see in practice are the result of underlying
management factors. Biosecurity lapses are one of those factors. We must stress to producers that it is futile to try to eliminate
a disease if they are not going to prevent its reintroduction. Different farms have different risks, and a biosecurity program
should be tailored to the individual operation. Risks of disease entry and spread should be evaluated and prioritized so the
most significant risks are addressed first. The practices discussed are just a start, and some farms, particularly those more
intensely managed like dairies and feedlots, might need more stringent work.
Dr. Navarre works as an extension veterinarian with Louisiana State University's Department of Veterinary Science.
Biosecurity on the Web
Visit the Center for Food Security and Public Health at
http://www.cfsph.iastate.edu/ for fact sheets on biosecurity, foreign animal diseases, zoonoses, disinfectants and more. Related farm assessment tools
also can be found on the site.