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From the commercial cow herd to the feedlot, cattle diseases are a growing concern. Veterinarians are stressing the importance of keeping herd health and biosecurity top of mind, as they will have a large impact on safety and profit levels going forward.
1. BOVINE VIRAL DIARRHEA
Commonly referred to as BVD, this disease is found most often in cattle younger than 2 years of age. It is the most costly viral disease in U.S. cattle herds today. One estimate reports exposure of feedlot animals to a persistently infected (PI) case of BVD will cost more than $67 per head in performance loss and fatalities.
BVD can infect several organ systems, causing suppression of the immune system, respiratory disease, infertility and fetal infection. Early infection of a bred cow can result in the birth of a PI calf. Once they are born, PI cattle shed the BVD virus throughout their entire lives.
"With BVD, you see a lower calf crop," said Tom Hairgrove, livestock and animal systems coordinator at Texas A&M University. "Vaccine programs are important, but they are only a part of a good herd-health program. Purchasing a PI animal or a bred female with a PI fetus can result in reduced reproduction for years. It is important to know your source of replacements and the health status of that herd."
Kathy Simmons, chief veterinarian for the National Cattlemen's Beef Association, added the cattle industry has worked to control BVD through research. The focus has been on a better understanding of the epidemiology of BVD, a wider availability of diagnostic tests to detect the disease and a clearer understanding of the economic impact it has on cattle herds. Visit www.bvdconsult.com for more information.
Good animal husbandry can help producers get a handle on the common infectious disease anaplasmosis. Also known as yellow bag or yellow fever, anaplasmosis is transmitted by exchange of blood. That means use of dirty ear tags, surgical instruments or needles spreads the disease, as do blood-sucking flies and ticks. It is estimated anaplasmosis costs cattle and dairy producers more than $300 million each year.
Cattle infected when they are under 2 years old usually adapt to the infection and are lifelong carriers. When older cattle become infected, symptoms include fever, weight loss, jaundice, abortion, anemia and erratic behavior because of a lack of oxygen to the brain. In some cases, anaplasmosis is fatal.
Hairgrove noted herd rebuilding is a common way that infected cattle are introduced to an operation.
"Anytime you comingle infected and uninfected cattle, you are risking the development of clinical anaplasmosis," he said. "Bovine anaplasmosis is a disease that has to be carried by flies or ticks, or bad husbandry practices."
Cases of anaplasmosis are more common in the summer and fall, when populations of insect carriers are higher.
There is one commercially available vaccine against anaplasmosis in the U.S., which will reduce death loss but won't prevent the disease. Common treatment includes the use of oxytetracycline and, in some severe cases, blood transfusions. Visit www.anaplasmosis.com for more information.
3. TEXAS CATTLE FEVER
A disease that almost wrecked the Texas cattle industry in the 19th century, Texas cattle fever (TCF), is still on the radar for producers throughout the country.