WHY VACCINATE?

 

J. Ivey Smith, DVM

Pork Production Center

Snow Hill, NC  28580

 

At best, vaccination can only be expected to assist in the reduction of disease, not eliminate it. No vaccine is a magical barrier against a particular disease.  When disease is a problem, the solution is not vaccination or changes in management; the solution is vaccination with changes in management or changes in management without vaccinations. Vaccinations will begin to take a more prominent place in health programs as drug residue concerns increase (and drug withdrawals by FDA increase), as technological and scientific advances allow new vaccine development, and as new diseases are identified.

 

We must first differentiate between "vaccination" and "immunization." Vaccination is the process of giving a vaccine to an animal. Immunization is the utilization of a vaccine by an animal to increase the level of protection against a potential disease.

 

Immunization requires:

 

1.      the appropriate vaccine (suggests the correct identification of virus or bacteria);

2.      vaccination in appropriate site (IM, IP, SQ, oral-NOT OF, OB, or OS);

3.      correct handling of vaccine (refrigerated, mixed properly, clean needles and syringes);

4.      appropriate dose (full dose, not half dose);

5.      appropriate timing (according to vaccine company);

6.      healthy animals capable of responding to vaccine.

 

There are several factors that will inhibit immune function:

 

1.      Cold – both extremes and fluctuations in temperature

2.      Behavior and social stress – weaning, mixing of pigs, etc.

3.      Nutrition

4.      Mycotoxins

5.      Ammonia

6.      Other diseases – There are many examples of infection with one disease causing pigs to be more susceptible to infection with another disease.

 

Giving baby pigs a healthy start can contribute to an enhanced immune response. Cold pigs are slow to drink colostrum, so help them get warm and dry quickly. Hang one heat lamp behind the sow from a few hours before farrowing until the last pig is born, and put lamps on each side of the sow during farrowing and the next 36 hours. Then heat only the designated creep area. As the litter nurses, check each nipple to be sure it's clear and dispensing colostrum. It's especially important to help low-birth-weight pigs (under 2.5 lbs.) get enough colostrum. Some will need help finding a free nipple.

 

    You may have to hand feed very weak pigs; milk 4-5 cc of colostrum into a small syringe, then feed the pig with the syringe or through flexible plastic tubing. You can milk easy-milking sows and freeze the colostrum in ice cube trays for later use. Thaw the cubes one at a time for individual pigs. Don't microwave them - you'll wreck the antibodies. Thaw the cubes gently inside a plastic bag immersed in warm water. Split-suckling can boost the whole litter's immunity. Hold larger pigs in the dry, heated creep for an hour or two after they've had colostrum, to give their smaller siblings a chance at the udder. Several products boost a pig's immune response by improving its nutritional status with extra energy.

 

There is a vaccine for almost every disease that can infect your hogs. That doesn't mean it makes sense to use all of them, even when you face an outbreak. You must first figure out how many of your hogs are sick or dying from the disease, then calculate the cost of vaccinating. The next step is to calculate the return from vaccination. This will take some best-guess estimating until you have some history with a particular vaccination program. If you are dealing with an outbreak that doesn't cause many deaths, but slows gains and reduces feed conversion instead, efficacy of the vaccine is much more difficult to pin down. Obviously, good records are critical so that you can track pre- and post-vaccination performance.