CLAY CENTER, Neb. — In 2014, due to a combination of factors including widespread drought and increased export demand, the U.S. cow herd shrunk to its smallest size since 1951.
Now, the nation’s herd is on the rebound.
But as cow/calf producers begin to rebuild their herds, veterinarian Dr. Richard Randle cautioned them to keep biosecurity in mind at the 2015 Farmers and Ranchers Cow/Calf College, held Jan. 27 at the U.S. Meat Animal Research Center near Clay Center, Neb.
“Anytime animals are (coming in), there is increased risk of introducing disease,” said Randle, University of Nebraska-Lincoln Extension beef cattle veterinarian in Lincoln, Nebraska. “This risk cannot be totally eliminated, but measures can be taken to minimize it.”
When many producers think of biosecurity, what may come to mind is a large facility and the long list of procedures and policies in place to protect the hundreds and thousands of animals inside. But Randle reminded farmers and ranchers that biosecurity is simply the term to describe a management-dependent approach to disease prevention and control, and therefore, any size of operation can benefit from having a biosecurity plan.
Randle defined biosecurity as management practices that reduce the likelihood of introducing a new disease from external sources as well as management practices that reduce the spread, severity and economic impact of infectious diseases if present.
As with any effective design, biosecurity planning begins with a risk assessment of the current situation. Randle stressed working with a local veterinarian, who is trained to spot gaps in animal health care on the farm. The purpose of the risk assessment is to find the farm’s biggest risk, which is done by weighing the potential effects of various animal diseases with likelihood of exposure.
Most farms find that the biggest risk area tends to be an inadequate vaccination program, poor condition of the herd or a current disease outbreak in the herd, Randle said.
“We know animal health is so dependent on so many other things management-wise, nutrition, parasites and so on,” he added.
Once risks have been identified and ranked, the next steps in a biosecurity plan are to establish objectives, define strategies and monitor progress toward meeting those objectives, Randle said. Each strategy would address a specific disease concern, such as mode of transmission, incubation period, duration of shedding of the pathogen, existence of a carrier state, test availability and reliability, and an effective vaccination program.
“This is where help from and working with your veterinarian is really important,” Randle said.
When considering biosecurity for expanding herds, Randle explained that the largest areas of concern include diseases that cause:
• Reproductive losses or reduced reproductive performance — Bovine Viral Diarrhea (BVD), Infectious Bovine Rhinotracheitis, Trichomoniasis, Vibriosis, Leptospirosis, Neosporosis, Brucellosis, among others;
• Long-term general health concerns — Calf scours, Summer pneumonia, Pinkeye, Anaplasmosis, among others;
• Lower marketability — Johne’s, Bovine Leukemia Virus, among others.
While a vaccination program is most effective at preventing disease, this is not always an option.
“We have some effective vaccinations for some of them. We have no vaccination for others,” Randle said.
When vaccination is an option, Randle reminded producers that it’s critical they read and follow the directions, particularly as they relate to dosing and timing, as mishandling a vaccination can render it useless. He also said that a vaccination program has to take into effect other biosecurity tools — like isolating new animals for a minimum of 30 days and performing appropriate diagnostic testing, to be most effective.
“We vaccinate individual animals, but what we’re interested in is the health of the collective herd,” Randle said, referring to the recent measles outbreak in the United States, putting unvaccinated children at risk and therefore the collective U.S. population at a disadvantage.
The more members of the herd that are vaccinated against a disease, the lower the susceptibility of the entire herd, he said. The fewer members of the herd that are vaccinated against a disease, the higher the susceptibility of the entire herd.