The name of the disease is somewhat misleading. Although symptoms of this problematic virus — bovine viral diarrhea (BVD) — in beef herds include respiratory disease, and of course, diarrhea, it can lead to even greater problems for beef producers.
"Diarrhea is such a minor part of this disease," said Gregg Hanzlicek, a Kansas State University veterinarian. "On a cow/calf operation, BVD's biggest impact is on cow reproduction. It depends when the cow is exposed during pregnancy on what's going to happen to her or happen to her fetus."
Cow infertility, early embryonic death within 42 days of gestation, aborted calves and calves born with skeletal abnormalities, can all occur in a BVD-infected herd, he added. When BVD enters feedlots and stocker units, it can suppress the immune system of calves and result in issues with bovine respiratory disease.
Because BVD has the potential to affect all of these beef industry segments, many in the industry are paying closer attention to it and paying a premium for calves that test negative as persistently infected (PI) with BVD.
In fact, video auction data show calves marketed in 2013 that had been tested and declared PI negative brought $2.97/cwt. more, a 23% increase from 2012. This translates to an additional $14 per head on a 600-lb. calf.
Hanzlicek said if a producer sent samples from a group of calves to the Kansas State Veterinary Diagnostic Laboratory for PI testing, it would cost a little more than $2 per head, so the return more than covers the cost. Producers can choose to send two different types of samples — tissue, such as ear notches, or blood.
"For herds that are at a high risk of having BVD, testing is economical, and it's a good part of a biosecurity program to keep BVD out of the herd," Hanzlicek said. "It's not typically for whole-herd testing. Test the youngest animals first. If there are no positives, then you can be fairly comfortable there is no BVD in the herd. If you find a calf that is PI positive, then you'll have to go back and test the dam."