Besides protecting the calf from disease, vaccinations help prevent having to use antibiotics later if the cow gets ill, said John Wenzel, New Mexico State University Extension veterinarian.
"The whole idea behind immunization is to prevent disease, rather than treating the disease,” Wenzel said. "Vaccinations are especially important now because if we do a good job of immunizing the calves before they get stressed, they don't get sick, or most of them won't get sick; therefore, we don't have to use antibiotics.”
Wenzel said not having to use antibiotics "boils down to a food safety issue. We don't have to worry about antibiotic residue or any of that type of stuff if we never have to use them. So the idea is to prepare the calf's immune system so we don't have to use any medication.”
A recently reissued publication by the NMSU Cooperative Extension Service titled "Cattle Vaccination and Immunity” written by Wenzel, Boone Carter, extension animal resources specialist, and Clay Mathis, extension specialist, explains how the vaccination stimulates the animal's immune system prior to significant natural exposure to disease-causing agents, called pathogens.
"The greatest stress in a calf's life is right after it is weaned because there is generally movement that occurs and a lot of exposure to pathogens,” Wenzel said. "Anything we can do to minimize the stress and maximize the immune system prior to that stress occurring helps the calf to fight off diseases.”
The publication discusses how the immune system works and how the vaccine makes the immune system respond. Included as topics is the difference between a modified live vaccine and a killed vaccine; how booster shots, or second vaccination, create a strong immune response of longer duration; and why it's important to follow the vaccines label directions.
"The idea is that we want the producer to understand why they are vaccinating so that they will do a better job and hopefully understand how important it is to follow all of the directions when it comes to vaccination schedules,” he said. "This paper is to help producers understand exactly why they are vaccinating and the theory behind vaccinations.”