Cattle Industry Contemplates Eradicating BVD
It seems unlikely that bovine viral diarrhea (BVD) virus could be made to disappear, given the size of the U.S. cattle industry and the diversity of ranches and feedlots.
However, that didn’t stop a group of veterinarians, producers, and industry leaders from considering it at a recent meeting organized by Thermo Fisher Scientific.
John VanLeeuwen, professor at the University of Prince Edward Island, Canada, explains the insidious and production-limiting nature of BVD. “It can produce persistently infected (PI) animals that look normal, yet they spew out the virus to the rest of the herd,” he says.
Research shows that costs of BVD can run up to $100 per head per year in infected herds. Many losses are due to reproductive failure but also are due to poor growth and diarrhea. BVD opens the door for many other cattle diseases.
To prove that eradication is possible, VanLeeuwen points to Norway. It took 10 years and $10 million, but Norwegian cattle farmers now save that much or more every year from no BVD.
The problem with extrapolating their experience is that the U.S. cattle industry is much bigger and more diverse. It gives hope for state or regional efforts to control BVD, however. In fact, a demonstration has been conducted in Michigan’s Upper Peninsula (UP).
“It was a five-year voluntary effort where we attempted to engage as many producers as possible in testing their herds for BVD and educating them on control,” says Dan Grooms, a Michigan State University veterinarian who helped lead the project.
Of the estimated 48,000 cattle in the UP, the project enrolled over half of them. Participating farms took ear notches from newborn calves and replacement breeding stock, and they sent the samples to the state lab. If a calf’s ear snip tested positive for BVD, it was eliminated from the herd and the mother was tested to verify her disease status.
Ranchers were also asked to evaluate and beef up biosecurity programs to minimize risk of new exposure. They also launched a BVD vaccination program (about $3 per dose) to prevent future spread.
Nine farms in the project had animals that tested positive for BVD, totaling 22 animals.
“That may not sound like many, but if those animals go to another herd, the damage potential is greatly magnified,” notes Grooms. “The PIs are the reservoirs of the disease.”
Four of the BVD-positive farms had regular contact between herds, through sales of cattle, or via fence line contact. “If you share cattle, you share the BVD virus,” says Grooms. “It’s a purchased disease.”
He says the cost of having the ear snip analyzed at a state veterinary laboratory is usually between $2 and $5 per animal.
Compare Your Program
Gregg Hanzlicek of the Kansas State University veterinary diagnostic lab says they have developed a computer demonstration tool for BVD risk. It lets cow-calf producers compare the economics of two or more management programs. Variables include herd size, herd-replacement strategy, quarantine program, vaccination program, BVD testing cost, and cattle prices.
“You can compare the expected gross revenue with your current biosecurity program to what you might expect with a premium program of perfect biosecurity,” says Hanzlicek. The demonstration tool will soon be available online.
When Hanzlicek demonstrates the program with an imaginary 100-cow herd, the revenue loss from low biosecurity can approach $30,000 or more by the third year, with most of the loss due to reproductive failures, he says.
Hanzlicek also points out that the premium approach is not always the most profitable when it comes to assessing BVD risk, particularly if you are in a low-risk area to begin with.