Managing BVD: Disease results in severe economic impacts
Disease results in severe economic impacts
Douglas – As part of the Wyoming Heifer Development Symposium on Sept. 11, Veterinarian Greg Goodell of The Dairy Authority, LLC in Greeley, Colo. discussed the bovine viral diarrhea (BVD) virus and the huge impact it has on herds across the United States.
“BVD is a complex viral disease that suppresses the cow’s immune system,” said Goodell.
BVD is an economically devastating disease for the beef and dairy cattle industries, commented Goodell, costing the industry $3 billion each year.
“It affects cattle of all ages from every herd size around the world and in every U.S. state,” he emphasized. “The rate of BVD in the U.S. is between one in 1,000 and one in 2,000.”
Around the world, the disease is more prevalent. For example, in China, BVD affects about one in every 200 calves.
If BVD makes it into feedyards, the disease can cost between $31 and $41 per head based on losses from lack of gain, lack of feed conversion and sickness.
“It causes large economic impacts,” Goodell mentioned.
Goodell noted that BVD results in breeding problems and may cause in abortion and congenital defects, as well as acute and chronic diseases related to immunosuppression.
“We see problems in our reproductive programs, and some ranchers will see problems with pneumonia or scours when they haven’t before,” he said. “A lot of times, when there are disease problems and we don’t know why, it’s because we have a persistently infected calf running around.”
“BVD is one of the most serious pathogenic viruses in cattle,” Goodell said. “It is a silent killer.”
Because of the negative effects on reproductive capabilities of cattle, the disease results in incredible economic impacts.
“BVD challenges overall animal and herd health and jeopardizes producer profitability,” he commented.
The BVD virus can result in two types of infections – transient and persistent.
“An exposed cow is transiently infected until the immune system flushes the virus,” Goodell explained. “If we have a cold that we recover from, it is a transient infection. The immune system has cleared it.”
Persistently infected (PI) animals are those that are infected at between 120 and 150 days of gestation.
“If the dam sees the BVD virus during gestation, the fetus will become a persistently infected animal,” Goodell said.
After birth, the PI animal sheds the BVD virus and infects other animals in the cowherd until they die or are removed from the herd.
While most die between 18 and 24 months of age, some live to adulthood and continue to spread BVD.
“Most PI calves, in my experience, appear healthy and may even look like the healthiest calf in the herd,” he said. “However, they are shedding millions of virus particles. Those are the animals that cause problems.”
“What is the difference between PI-BVD calves and others?” Goodell asked. “PI calves recover from scours or pneumonia. They can get better from Pasteurella or respiratory virus, but they do not recover from BVD.”
The bottom line, he continued, is that they need to be removed from the herd after being identified through testing.
“Testing for PI cattle is different from testing for many other diseases,” he continued. “The PI status of an animal will stay the same. Once they are PI, they are always a PI animal.”
As a result, all animals that are PI-BVD calves need to be euthanized and removed from the system.
Producers have the option to test calves for BVD for a relatively small expense, compared to the economic impacts the disease may have, and Goodell noted that testing often provides a premium at the sale barn.
“The test costs around $3.50, depending on the number of samples,” he said. “According to Superior Livestock Auction, buyers paid $2.42 per hundredweight more for BVD-tested calves at auction.”
On a 600-pound calf, the result is an approximate $10 per head net profit for tested cattle.
The premium results because of the costs that BVD has in feedlot settings.
In one example, a 10,000-head feedlot was analyzed. With only 0.4 percent prevalence of BVD in the cattle, 72 percent of pens were exposed to the disease.
“The observed cost per animal was $47.92,” he explained.
The resulting feedlot costs were $479,200. Compared to testing costs of $35,000, Goodell said that the economic benefits make a difference.
“Testing is critical,” Goodell said. “The only way to identify BVD is through testing, and the earlier producers test, the quicker the PI calves can be removed from your system.”