A recent multi-university survey of 61 veterinarians in six states found that 87% recommended vaccination of nursing calves to prevent BRD or to shorten the duration of outbreaks, says Brent Meyer, D.V.M., beef cattle technical services manager for Merck Animal Health.
Terry Engelken, D.V.M., M.S., associate professor at Iowa State University College of Veterinary Medicine, was involved with the survey. Engelken says it identified risk factors, as well as practitioner recommendations for preventing and managing BRD.
A key risk factor mentioned was inadequate colostrum, which could be caused by anything that interferes with the calf standing up rapidly and nursing aggressively.
"We know from extensive research and practical experience that calves not receiving enough colostrum run a higher risk of developing calf scours early in life followed by BRD while they are out on pasture," Engelken says.
The losses associated with BRD in nursing calves include both the obvious and those that are not so apparent. Medical expenses, labor costs and death losses are straightforward and easy to calculate. It is more difficult to track weaning weight losses in individual calves after they recover from a bout of BRD.
"Research indicates calves that get sick for any reason during the suckling period will weigh from 20% to 35% less at weaning compared to their healthy herd mates," Engelken adds.
In addition to the impact on performance, researchers are looking into the effect of nursing calf morbidity on carcass ultrasound characteristics at a year of age.
"Recent work that analyzed the effect of morbidity due to pinkeye," Engelken says. "The ultrasound results found that calves that were treated for pinkeye during the nursing period showed a decrease in marbling and ribeye area when measured at a year of age.
"I would expect similar results for nursing calves that had morbidity due to BRD."
Develop a plan
No single vaccination program fits all, so it's important to work with a veterinarian to help create a vaccination plan for both dams and calves, Meyer says.
The goal of the program is to reduce the disease pressure of the group, which should have a positive impact on the bottom line.
"A veterinarian can identify the risk factors for BRD that reside within the management scheme on an individual farm or ranch, and once they are identified, recommend how to mitigate them," Engelken says. "They also will get a handle on the disease pathogens – bacteria or viral – that are circulating and help determine the best timing to vaccinate for these pathogens."
This process may require sampling of individual calves with BRD or collecting tissues from dead calves and sending the samples to a diagnostic laboratory.
Summer turnout, preweaning and/or weaning are opportune times to prevent disease.
Many veterinarians start with a modified live five-way viral vaccine (IBR, BVD1, BVD2, PI3, BRSV) and a dose of "blackleg" vaccine. Other vaccines may be recommended depending on: the potential health challenges present on the ranch; if the operation is on a preconditioning marketing program that requires a certain set of vaccinations; and, how the calves will be managed after weaning, such as if they will be retained through the feedlot.
"Typically, the first additional vaccine would protect against bacterial BRD pathogens, such as Mannheimia haemolytica and Pasteurella multocida," Engelken says.
For more information on Merck's cow-calf vaccine offerings, visit www.CattlePrimeVAC.com.