Biosecurity: Stakes are high; help producers with a plan
Feb 01, 2003
Dr. Dee Griffin, extension feedlot veterinarian at the University of Nebraska says that if you have not taken on biosecurity issues for producers, it's a natural extension of consulting whether on cow-calf, feedlot or dairy operations.
In an interview with DVM Newsmagazine, Griffin says that practitioners could help create a producer biosecurity plan.Griffin explains, "Once the veterinarian goes through an operation with the owners and employees and evaluates the risks, I think everyone is on a better footing to really understand biosecurity."
Biosecurity's goal is to protect animals from disease by minimizing the movement of biologic organisms. Griffin adds that a biosecurity program has five specific components: assessment, resistance, isolation, traffic and sanitation.
Assessment The first step in any biosecurity program is to assess the risks to an operation, and you can do it by outlining specific diseases. Each specific disease can then be evaluated as it relates to the potential for herd exposure, potential impact on the herd and potential for biosecurity control, Griffin explains.
It's important to start the assessment by identifying the likelihood of exposure to disease-causing pathogens. Factoring in the lifecycle (age) of animals is also important in the assessment, and so is identifying potential wildlife influences including migratory patterns of birds.
Griffin says, "I live in Nebraska, and we are the flyway for lots of ducks and geese. So, we had to start thinking about what kind of things those flyways present to us. We don't see much botulism in livestock at all, but it is possible. All it would take is a duck to die in someone's pond and contaminate the water."
Another biosecurity risk is when a dead animal inadvertently makes its way into the combine when feed is being mixed.
Griffin says to take each disease and identify the possible routes of exposure to the herd.
Resistance The next step in forming a biosecurity strategy is to identify ways animals can resist acquiring the disease. Resistance refers to enabling an animal to reject or contend with an infectious agent. An animal's resistance involves both specific immune training and general metabolic mechanism. Griffin says this stage is to identify ways to make those animals more resistant to infection." Sometimes this translates to vaccinating animals; other times it may simply mean there is no way to protect against a threat, he says.
Foot and mouth disease, if it ever made its way into the United States, could be very costly, simply because there are no approved vaccines to prevent its spread. With other diseases, vaccine may help control flare-ups in a herd, but it may not entirely control the problem. "There are a lot of vaccines where resistance may be helped, but they are not going to totally control the disease," Griffin adds.
Resistance to disease is supported by proper nutrition and minimizing stress. Once identified, these resistance goals can be trained to ranch or farm personnel, too.
Isolation Isolation has been a hallmark of swine operations for decades, Griffin adds. And many of the same principles could be used with cattle. Isolation refers to the prevention of contact between animals. The first steps to disease control are to minimize commingling and movement of cattle, including new purchases, and animal movement between the veterinary hospital. Another important strategy is to separate cattle by age and/or production groups.
"When you think about it, we raise our livestock in pretty open environments. Isolation has to be rethought." Griffin adds that since young animals are much more susceptible to certain diseases because their immune systems are still developing, isolation could play a key role when considering an animal's age and when to commingle calves.
Traffic Does a farm or ranch have a predictable protocol for traffic patterns? Griffin adds that traffic control is more than simply controlling the movement of people on the farm, it also has to do with traffic control of animals, including dogs, cats, horses, wildlife, rodents and birds. He adds, "The degree of control will be dictated by the biology and ecology of the infectious organism being addressed."
In other words, stopping a livestock hauling truck from entering an operation as a biosecurity measure to control a disease that is only spread by animal-to-animal contact is probably not going to offer much protection.
In addition, vehicles should not travel from the dead cattle area without cleaning and disinfecting.
Sanitation Practicing good sanitation methods, including disinfection, is a big area veterinarians could help producers. Understanding how to clean and the proper cleaning agents is a huge part of training, Griffin explains. (See Tables 1 and 2, p. 1F.)
"Most disinfectants are denatured or not active in the presence of organic matter. In other words, disinfecting a dirty bucket cannot be done until you get the dirt out."
The first objective of sanitation is to prevent fecal contaminates from entering the cattle orally. Problems could occur when a loader is used to clean out a stall and later used to mix feed without being properly sanitized first.
Envelope and non-envelope viruses are two important distinctions that could determine the type of disinfectant to use.
Common disinfectants like chlorhexidine, alcohol, phenol and quaternary ammonium are not effective against non-envelope viruses. Non-envelope viruses include bluetongue, rotavirus and papillomatosis. Aphthovirus, or foot and mouth disease, is also an example of a non-envelope virus.