An ounce of prevention is worth a pound of cure. There's no doubt about that when it comes to something like foot-and-mouth disease-hence the effort the United States is undertaking to keep it out of thecountry. It's national biosecurity.
Meanwhile, on a smaller scale, biosecurity remains a goal for every producer. Biosecurity is about more than foot-and-mouth-it's about basic animal health. "The concept is to avoid introducing anything into the production system that will damage the process or the product," says Steve Henry, veterinarian with the Abilene Animal Hospital in Abilene, Kan.
But the news from abroad has highlighted the need for biosecurity, and as producers start thinking more about keeping other disease-causing patho-gens out of their herds, they'll realize that biosecurity requires a plan. "You have to identify risk factors from a disease and an economic standpoint and then devise a strategy," says John Thomson, dean of the college of veterinary medicine at Mississippi State University. That strategy will not be static, since conditions on any operation are always changing. "It's not something you draw up one day and that's the plan."
A few basic questions help to shape a biosecurity strategy.
- What is in your population already? Absent that information, you might unwittingly devote your efforts to trying to keep out some pathogen that's already present.
- Is it worth your efforts to keep out a certain pathogen? What would the effect be? Production records are crucial to answering that question: pregnancy rates, calving rates, weaning rates and weaning weights. "Records from several years are more valuable than from one year, but a long journey must start with a single step," says Bob Larson, veterinarian at the University of Missouri.
- How effective will your efforts be? Dr. Larson suggests your veterinarian can help answer this by discussing such factors as incubation periods; clinical signs; whether silently infected animals spread the disease; whether other species can spread a particular disease to cattle; how different diseases are transmitted from one animal to another; what tests are available for diagnosis of diseases and their accuracy; the effectiveness of available vaccines; and length of time the causative agents remains infective in the environment.
- What kind of risk can you stand? Biosecurity is basically an economic decision. There's a cost to getting disease and a cost to preventing it; balancing the risk depends on many factors. "If the population is a commercial herd, it would have a different impact than one that provides genetic material globally," Dr. Thomson says. "They would have different economic risk."
Keep in mind that the true cost might not show up until later-maybe a particular disease won't mean dead animals, but limited opportunities. "Many times, people say it won't make any difference if I get that disease," Dr. Thomson says. "But sometimes it will shut out an opportunity." For example, when heifer prices are high and you want to sell replacements, an infection could hurt their marketability.
Dr. Henry divides biosecurity risks into four categories: animals, people traffic, mechanical traffic, and inputs, which include feeds, drugs and implants. "We worry a lot about microbial pathogens," he says. "As systems become more tuned to biosecurity, there will be more assurances needed that such bases are covered."
Supplier credibility will become increasingly important. "The practice of buying from the cheapest and closest is being supplanted a little bit by who offers the best assurances," says Dr. Henry. In the byproduct arena, for example, "you've got to make sure that if they say there's no bone meal in the feed, there's really no bone meal."
The categories of people and mechanical traffic become important with pathogens such as salmonella, which can survive a long time in the environment. Starting disinfecting protocols for vehicles and visitors is likely to become increasingly standard. Recently producer Lynn Cornwell was glad to be denied a visit to a feedyard in Canada; it meant they were taking biosecurity seriously. "I was tickled they were doing that," he says. At Mr. Cornwell's ranch and custom feedlot near Glasgow, Mont., the policy is that all visitors must report to the office before getting near the animals.
New animals are another biosecurity risk in any operation. "The ideal would be having a completely closed herd, but I don't know of a completely closed herd," says Michael Sanderson, assistant professor at Kansas State University.
The next best thing is importing from herds with known disease status. Mr. Cornwell, who is also president of the National Cattlemen's Beef Association, limits new animals coming onto his ranch. That's why he only buys bulls from a reputable source.
It's not only purchased bulls or replacements that pose a risk. Other practices which open a herd to other animals can be less obvious: using sale barn calves for grafting; buying colostrum from a dairy; sending heifers to a heifer development program; transporting cattle in a vehicle that transports other cattle; sharing a fence with neighbor's cattle. All such practices are possible biosecurity risks.
When importing cattle is necessary, experts suggest quarantine and testing protocols. Isolated cattle should not share feeders, waterers, or even airspace with other cattle, since many infectious diseases cannot live long away from the animal. But quarantine is not effective if an animal has a latent infection that cannot be detected during the quarantine period. So animals also should be tested for, and vaccinated against, transmissible diseases during their quarantine. Of course, testing is fallible as well since tests don't always perform perfectly. Knowing the status of the herd of origin is the best bet.
Wildlife may be a wild card in a biosecurity plan, as wildlife can be a source of diseases such as BVD (bovine viral diarrhea) and leptospirosis. It might not be a problem that can be truly solved, but it must be figured into a biosecurity program. "If you're going to devise some plan, have all this isolation and then throw them out on the open range, you're not using common sense," Dr. Thomson says.
By their nature, feedyards come with their own set of biosecurity troubles. "The whole way feedlot cattle are procured is pretty well set up to have trouble," Dr. Sanderson says.Concentrating animals together multiplies the risks, and quarantines and testing to exclude are not practical here.
So knowing their cattle's origin is even more critical. "I think developing the mentality that life does not begin when they enter the feedlot would help," Dr. Thomson says. "Where are you getting these animals?"
Still, in many cases, pathogens will already be present. "The most common things in feedlot cattle are everywhere: IBR, BVD," says Dr. Sanderson. "Trying to exclude those from a feedlot is not a realistic goal. You're really managing the manifestations of those. They're all exposed, but they don't all get sick."
Making sure they've had good nutrition and are preconditioned and bunk-broke can change disease rates dramatically. Sanitation is also key, especially with feedbunks, water troughs and equipment. "It's impossible to be sterile, but you can be clean," Dr. Larson says.
Commingling practices can be a biosecurity concern: don't put the receiving pen next to hospital pen, or keep constantly introducing new animals to a pen. "Sometimes they have open entry for weeks," Dr. Thomson says. "Not many do, but I see it enough. It keeps the population stressed all the time." Commingled animals need to all be handled in the same way in terms of vaccinations and parasite control.
Because of Salmonella, cryptosporidiosis and other diseases that can be passed by dogs and cats, keeping your own and other pet animals away from your cattle is an important aspect of biosecurity. Rodents and birds should also be kept at bay, which is somewhat more challenging. "A professional exterminator may be part of how you plan to run your farm," Dr. Larson says.
Biosecurity is really just a standard of hygiene and expectation. It borrows from many concepts already in use on swine operations, where they've been working on biosecurity for years. "Thirty years ago, they said this level of biosecurity could never be reached with pigs," Dr. Henry says. Now that the beef industry is starting to talk about it, we may be surprised a few years from now at how things have changed.