Proper Use of Vaccines is Essential

Dr. Arlen Mills, Extension Veterinarian, Capital Region, Pa.
November 30, 2001

Vaccination is an essential part of any infectious disease control program for dairy farms. But to be successful, it must be planned to meet the needs of each operation. It must be remembered that vaccines hopefully increases the animal’s resistance to disease, but that resistance can be overwhelmed if good management practices are not followed.

A question which comes up with several of the viral infections is whether to use a killed vaccine or a modified live type vaccine. This continues to be debated but the current consensus is that, especially for the first immunization that a young calf receives, modified live vaccines give superior protection.

Setting up a vaccination program means determining: (1) Which diseases to vaccinate against. (2) Which animals to vaccinate. (3) When will the animal most need the protection that is to be provided. In light of this, a basic vaccination program that I recommend will be presented. Remember that this may need to be discussed with your veterinarian to determine what is best for your farm situation.

On most farms, calves can receive their first immunizations at four to six months of age. This is where the use of a modified live vaccine is recommended containing BVD, IBR, PI3, BRSV and lepto. I want to see this repeated in four to six weeks to get those calves which did not respond to the vaccine initially and to ensure good BRSV protection. On some farms with respiratory problems in the younger- age calves, I have vaccinated earlier, using this same vaccine or with just a modified live BRSV. Early vaccinated calves get a booster at six months of age.

On some farms I like to see calves vaccinated with a Clostridial bacterin as well at the four to six month age. I am recommending this more often now as we seem to be seeing more of the Clostridial enteritis in dairy herds. This might give us some protection and the cost is minimal.

The next vaccinations are due as prebreeding boosters. At this time I like to see the modified live vaccine containing BVD, IBR, PI3, BRSV, and leto repeated. In herds which have had a Salmonella problem, I like to start heifers on a core antigen type bacterin at this time as well.

The next stop is the dry cows and prefresh heifers. In herds with viral disease problems, I may give a killed viral booster vaccine at this time. This would include BVD, IBR, PI3, BRSV, and lepto again. I use killed at this time as I should have good immunity from the modified live vaccine given earlier and the killed vaccines are labeled for use in bred animals.

The dry cows and prefresh heifers may also get a J5 bacterin-toxoid to prevent coliform mastitis. The number of doses will depend on the vaccine used. Some like to give a vaccine for calf scours at this time as well. My feeling is that the J5 bacterin will give some E coli protection to the calf through the colostrum. I am not a big fan of the Rota and Corona scour vaccines but if you like to use it, this is the time for that as well. Do not vaccinate within a week of freshening, or the week after freshening either. During this critical time the cow’s immune system is depressed to the point of not being able to respond to a vaccine.

I see a lot of variation in the vaccination of the lactating cows. If the young stock vaccination program is being done properly, then I find that the type of vaccine used in the adult cows isn’t as critical. Some producers are using a modified live vaccine as a booster for all fresh cows prebreeding. Just remember that the label cautions use around bred animals. Others are using killed products in the lactating cows successfully. Discuss the pros and cons of each with your veterinarian.

In the last several years, I have seen more and more respiratory problems in adult cows. Switching these herds to a vaccine that had a live BRSV fraction in the lactating cow booster, seemed to be helpful. These herds had not been using a modified live vaccine in the young stock which I’m sure is part of the problem.

A successful vaccination program takes careful planning. The successful vaccination program must be scientifically correct and supported by good management practices.