Cattle biosecurity critical for modern operations


Americans have always been on the go, and the same can be said of the country’s cattle herds lately.
Unfortunately, the movement of cattle back and forth across the country can also increase biosecurity risks, experts say.
Hidden dangers can lurk in trucks that have not been properly cleaned, and animals can get sick after arrival if they’re naïve to diseases at the new location.
Producers can also unwittingly introduce diseases onto the farm or ranch with a new bunch of cattle.
Last year, many herds in the Southwest were moved to greener pastures because of drought.
Certain situations can escalate transportation risks, as when a load of bred cows is loaded onto a truck that has just hauled high-risk calves.
“We know that some of these pathogens can live for an extended period of time in manure and urine,” says Mac Devin, professional services veterinarian for Boehringer Ingelheim Vetmedica Inc.
Devin, who lives in Texas, has this advice for cattlemen: “Just make sure that transport equipment has been washed out and cleaned before hauling a different class of cattle.”
Quarantine, testing and vaccinations are key elements of a good biosecurity program, experts say.
Quarantine policy
The goal is to prevent bacteria, viruses and parasites from being introduced onto a livestock operation in the first place.
If breaches do occur, a sound biosecurity program could help limit the spread of the disease and minimize losses.
Cattlemen always take on some risk when receiving animals from outside their area, even if they have a certificate of veterinarian inspection.
Most herd vets encourage producers to quarantine and test incoming cattle.
In general, newly arrived cattle should be isolated from the resident herd for 30 days to six weeks, says Bob Larson, a professor of veterinarian medicine at Kansas State University.
If there’s a disease outbreak during that time, the quarantine period should be extended, he cautions.
Quarantine can expose diseases that typically manifest themselves within a few weeks, but there are other diseases that may be present without showing any outward signs.
Bovine viral diarrhea (BVD), trichomoniasis and anaplasmosis are a few of the diseases that have the potential to infect an animal for life.
“In that case, a six-week quarantine isn’t going to solve the problem,” Larson says. “That’s why it’s a good idea to combine the quarantine with some diagnostic tests.”
Testing efficacy
Effective tests are now available for diseases such as BVD and trichomoniasis which, left unchecked, can cause devastating reproductive losses.
Producers shouldn’t overlook newborn calves during testing.
“People will buy a set of bred cows and have them tested, but not test the calves when they’re born,” Devin says.
“That’s probably one thing that trips people up the most,” he says. “You can have a PI calf (one persistently infected with BVD) inside a cow that’s perfectly normal.”
Producers should select the quarantine site carefully. They obviously don’t want to set it up in a corral where they’re going to be processing baby calves a short time later.
“Where we receive these cattle is pretty important,” Devin says.
Sunshine will sanitize most outdoor quarantine areas given sufficient time, but cleaning up a shed or other indoor facility takes more effort.
That’s especially true if there are known risk factors, such as a shed that’s been used to house baby calves suffering from scours, Devin says.
In that case, the shelter must be thoroughly cleaned and sanitized.
“You’d need to remove the manure, remove anything that has the potential for cross-exposure with cattle that are native to the ranch,” he says.
Reproductive diseases aren’t the only concern when bringing in cattle from outside.
The new arrivals could also be carrying weed seeds or parasites that a rancher would prefer to keep off his spread. A quarantine period can help mitigate those risks as well, Devin says.
Vaccination protocol
Vaccinations should be part of any biosecurity program, experts say.
A good vaccination program accomplishes two primary objectives:
First, it helps raise the herd immunity to a level where there is very little chance for an outside pathogen to gain a foothold.
Second, it helps individual animals develop an immune response so they can fight off harmful pathogens if exposed.
The timing of vaccinations is important, Devin says. The goal should be to provide the animal with the greatest amount of protection at the point of greatest risk.
That means administering vaccines for venereal diseases such as trichomoniasis and vibriosis, before breeding season.
“In that case, we want our greatest immunity at breeding season because that’s the only time those diseases are actually going to be transmitted,” Devin says.
Protecting cattle from outside threats is crucial, but it’s only one part of an overall biosecurity program.
Diseases that tend to be more regional, such as bovine leukosis or leptospirosis, can be a serious threat to cattle that have never been exposed to them.
“Producers need to ask themselves, ‘What am I bringing these cattle into right here where I am that may be different than where they came from?’” Devin says.
Disease threats can also lurk just across the fenceline, so it’s important to coordinate a biosecurity program with neighbors, experts say.
“It’s not just what we buy,” Devin says. “It’s what’s going on around us.”
While there have been some significant advances in vaccines and other bovine medications in recent years, producers should not view them as a panacea, experts caution.
“As producers, we tend to think about managing disease with something that comes out of a bottle,” Devin says. “But the reality of it is that it takes a complete prevention program to manage disease, particularly if you have transient animals.”

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