Relatively new resources for bovine viral diarrhea (BVD) control programs are within reach of nearly every cattle producer in the U.S. Successful and cost-effective BVD control needs to involve an organized approach using risk assessment, biosecurity measures, surveillance and testing, and, of course, effective vaccination.
Although no vaccination program is 100% effective, vaccination is essential in helping prevent acute or transient BVD virus infections, says Dan Grooms, DVM, Michigan State University. “For reproductive herds, BVD vaccines should be used to reduce the risk of fetal infection, including those resulting in persistent infections.”
Grooms stresses that BVD vaccines should be applied in a manner that provides a high level of immunity to the breeding heifer or cow just before breeding and maintains that immunity throughout gestation. He and his colleagues emphasize that both killed and modified-live virus (MLV) vaccines have been shown to be safe when used according to label instructions. But, more and more, the research community is leaning toward MLV vaccines.
“Vaccines are manufactured in a variety of combinations to facilitate many different management regimes,” he explains. “In general though, MLV vaccines are believed to be more effective and should be incorporated into vaccine programs.”
Dan Givens, DVM, Auburn University College of Veterinary Medicine, says selection of vaccination protocols for each operation should be based on:
Risk of disease introduction.
Reliability of the vaccination protocol.
Cost of vaccine.
Cost of vaccine administration.
Safety of the vaccination protocol.
Ease with which vaccination protocols are integrated with other management.
Questions associated with ownership or management transfer.
Effectiveness of communicating the value of prior immunization.
Givens and other researchers have developed a BVD vaccination “reliability rating” for producers and their veterinarians to use in assessing vaccination protocols for calves, heifers and cows and bulls (Table 1 , Table 2 , and Table 3 ).
This is all part of raising the bar on BVD control in North America, says Grooms. “With the eventual goal of BVD eradication in North America.”
Clint Peck is director, Beef Quality Assurance, Montana State University.
BVD risk analysis
The risk for bovine viral diarrhea (BVD) infection in a herd depends on the management of the ranch.
“There's always some risk the virus will be introduced into a herd,” says David Sanderson, DVM, Kansas State University. While actual occurrence of BVD is occasional, Sanderson says the actual amount of risk varies.
Sanderson has developed a risk-analysis model that producers can use in consultation with a veterinarian who understands the BVD virus and the function of risk management in biosecurity and biocontainment.
“We need to look critically at which practices are effective and economic,” he adds. “One way to do this is by a risk-analysis process.”
For more information:
Kansas State University BVD risk analysis: http://184.108.40.206/bvdvmodelweb/default.aspx .
Montana State University BVD biosecurity risk assessment: www.mtbqa.org .
“Integrated BVD Control Plans for Beef Operations” www.bvdinfo.org .
Academy of Veterinary Consultants: www.avc-beef.org/links/BVDLinks.asp .