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VACCINATION PRINCIPLES SANTA GERTRUDIS Product ion Randy L. Stanko, Ph.D., Texas A&M University-Kingsville W hen discussing herd health and vaccination programs with fellow beef producers, you will discover much variation exists

cines (modified live) can replicate and produce a mild case of the disease after vaccination. Infectious vaccines control viral and bacterial organisms that invade body cells. These vaccines are more effective, and many can now be given to bred females. Please carefully read labels before ordering/ purchasing any type of vaccine. Moreover, infectious vac- cines will have to be prepared (mixed with a diluent) prior to use, cannot be stored for later use and can be destroyed by excess light and high temperature. For cow-calf producers, noninfectious vaccines are likely the more familiar products. There are now multiple combi- nation vaccine products (modified live and killed vaccine). Because of the nature of the vaccine, two doses given 3 to 4 weeks apart is most effective. Approximately 14 days fol- lowing an initial vaccination, cattle will produce an immune response and set up the immune system “memory.” Follow- ing the second booster vaccination, the cattle will produce a robust immune response that can last 10 to 12 months. To maintain disease protection thereafter, an annual vaccination will suffice. If calves will leave the ranch after weaning, I believe it is important to vaccinate 2 to 4 weeks prior. Calf buyers, regardless of known calf history, typically vaccinate soon after calf arrival, but may or may not booster immunize them later. Either way, disease protection is correctly established. Always read and follow vaccine label directions and consult veterinarians for specific recommendations on vaccination protocols in your areas. When given a route of administra- tion choice, subcutaneous is preferred over intramuscular to maintain beef quality and happy beef consumers.

from one ranch to the next. I person- ally know small producers who have closed herds and rarely vaccinate cattle. I also know producers who have extensive herd health programs and vaccination protocols that would make health official Dr. Fauci proud. No matter where a specific producer is on

this spectrum of vaccination programs/protocols, it behooves us to understand immunity and the principles of vaccina- tion. Vaccinating beef cattle, especially cattle managed to navigate the commercial beef supply chain, is simply good livestock stewardship. Cattle have three ways to protect themselves from infec- tious agents. First is access to fresh water and good nutrition, the hide, grooming, sneezing and coughing. In other words, healthy cattle and typical behaviors. Second is their innate (or native) immunity. This component of the immune system lacks a memory and treats each challenge the same, usually by quickly controlling invasion of pathogens through body chemicals or attacking and engulfing the organisms. The third way is the acquired immune system. This system has a memory and can effectively seek out and destroy specific disease-causing organisms. Acquired immunity is what develops through a good vaccination program. Unfortunately, this immunity takes days to weeks to establish. However, once established, acquired immunity involves the produc- tion of antibodies and “killer cells” that can rapidly identify, neutralize and eliminate the disease challenge. There are two types of injectable vaccines: infectious and noninfectious. Pharmaceutical companies produce vaccines that contain modified (live) or inactivated (killed) organisms, or parts of organisms, or inactivated toxins. These products will stimulate acquired immunity and production of antibod- ies. In addition, we can also purchase health products that are antibodies, for example tetanus antitoxin. These prod- ucts are not to be confused with infectious and noninfectious vaccine products because they will not produce long-term protection. Vaccination should occur prior to disease exposure. Non- infectious vaccines (killed products) are not able to infect cattle nor replicate, and are best at controlling pathogens that attack the outside of body cells. Organisms that cause blackleg and tetanus are good examples. Infectious vac-

George West, Texas (361) 566-2244 lacampanaranch.com campana@granderiver.net

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