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Wean Right - Immunize as well as vaccinate One of the most stressful times in a calf's life is approaching as weaning time nears. Separation from their dam, being run through a chute, being shipped/moved to a new area, and, particularly for some of the bull calves, castration. All of these stressors can combine to make an animal quite immune depressed, with can lead to an increased incidence of respiratory disease. So this is the perfect time to give an animal it's first vaccination for common diseases? No. The key point in managing our calves is that we want not just to vaccinate them...we want them to develop protective immunity. How to do this? Take the time to run the calves through the chute 3-4 weeks prior to weaning, giving them a modified live 4-way vaccine(MLV), deworming, and castrating bulls. Additional vaccinations for bacterial pneumonia or clostridial disease may be considered depending on the farm's situation. But, the important factor here is that the calf will have the time to develop initial immunity without the stress of weaning and more importantly, will have that immunity on hand when weaning actually does occur. The other factor is selection of vaccine. Products such as BoviShield4L5 have a modified-live BVD and IBR component, which cannot be given to pregnant animals, but allow the development of a much stronger and long lasting immunity than killed vaccines, plus they are often less costly and a smaller volume injection. This will factor into vaccination strategies later in the animals life as well - those heifers given killed vaccine as weaned/pre-weaned calves will need two boosters of killed BVD per year to provide protection will those with a MLV vaccination history will be protected adequately with one booster. The simple reason for this is that a MLV vaccine produces a very mild form of the infection, almost always unnoticeable in the animals behavior/appearance, but very noticeable to the immune system. Because the viral particles replicate many times, there is a greater opportunity for the immune system to interact and thus provoke a more complete and long-lasting immunity in the animal. Formation of so-called 'memory-cells' occurs more often and gives the animal a greater chance in the future to recognize and neutralize disease causing invaders in the future. Follow-up vaccination should be done at the time of weaning to provide the proper booster. As with nearly all vaccines, skipping the boostering step truly reduces the value of the first shot, preventing the animal from producing a long-lasting solid immunity. This is particularly true with killed vaccines, such as CattleMaster4L5 or ScourGard3K+C. This is also a good time to overview handling of vaccines. Failure of a vaccine to provoke immunity, which is not uncommon, is very, very infrequently due to a defective product received from the manufacturer. Very often it lies in our own hands in the chain of events from receiving the product until actual injection to the animal. And, as well, it can often be due to an inability of the animal to respond to a correctly administered vaccine, such as an animal in poor body condition, in a period of severe stress(a newly castrated and weaned bull for example), or an animal that is heavily parasitized. The link between parasite load and loss of immune function is well established. So, in an aside, be sure to include deworming in the fall management of calves. A very good choice is a long-acting avermectin, such as DectoMax, in an injectable or pour-on formulation that will provide 28+ days of control from one dose. Shorter acting avermectins, such as Ivomec or Eprinex, or the Valbazen/SafeGuard products are also excellent choices for deworming, but it must be remembered that these require a follow-up dosage in 4-5 weeks to obtain the proper results. Vaccine Handling Points 1. Store all vaccines properly according to label directions 2. Observe expiration date and discard those that have passed the date 3. Mixing of vaccines must be done with a new needle and syringe. Use of a double ended needle allows an aseptic method of mixing. DO NOT use any syringe that has been washed with disinfectant or soap. THIS IS CRITICAL, it can allow the inactivation of m-live virus and defeat the attempt at immunization. 4. Use mixed vaccine within 2 hours of mixing and keep from sunlight. 5. Inject in the neck as directed, either SC or IM, according to label. 6. Keep epinephrine on hand in case of any anaphylactic reaction. They happen. 6. Make frequent needle changes to prevent disease spread and to allow easier injection and less pain for the animal. So, if you're going to wean in mid-late October, take the time now to run your calves through the chute, get them started on developing strong immunity-reduce parasite burden, and make the stressful transition of weaning easier on them. They will pay you back with less incidence of disease/death loss and improved performance.
a note on bvd:Bovine Virus Diarrhea (BVD) is a disease of cattle which reduces productivity and increases death loss of cattle. Clinical signs of mucosal erosions and diarrhea in the acute form of BVD has a significant effect on those animals infected, but much more costly are those animals who are persistently infected animals or PI. They typically fail to reach their potential exhibiting decreased weight gain, increased disease susceptibility, and reduced fertility, and by shedding the virus, cause reproductive loss in the unimmunized animals in the herd. Most important to programs that reduce or eliminate BVD are vcaccinations, testing, vaccinations and biosecurity. MLV vaccinations(for example, Bovishield4L5)is most important at providing superior immunity to bvd. PI(persistently infected animals)animals result from cows being exposed to the virus during mid-gestation and the fetus fails to recognize the virus as a foreign invader, allowing the infection to persist after birth and allowing them to shed the virus in such great numbers, such that even well-vaccinated animals may become infected.
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