Print This Article

When disease agents have entered the herd, intervention may become necessary. Once you've identified the agents, and evaluated the economic impact, a game plan is ready to put in place. Given the impact of season, the respiratory health plan may have to change with time as well! Remember to look at all interventions — vaccines, strategic medication, and changes in production flow — when putting together the plan of attack.

What is “Strategic Medication”?

Strategic medication is just that — medication applied at important points to minimize cost and maximize return. When timed correctly, strategic medication reduces performance loss while allowing pigs to begin to develop natural immunity.

Continuous medications may seem simpler at first, but they run up costs unnecessarily and may risk development of resistance. Additionally, they prevent pigs from developing any immunity to protect them against future infection. Once medications are removed, pigs are still susceptible and will get sick when re-exposed.

For example, a production system used strategic medications in several grow finish diets. Vaccines had improved performance by reducing the impact of Mycoplasma, but mortality was still higher than desired. By combining vaccination and strategic medication, mortality rates in heavy pigs were cut in half! As compared to a program of typical continuous medications (e.g. tylosin), mortality was reduced from 8% to 4% when strategic medication with Denagard^™ Plus was used.

Don't forget PRRS

Good health control programs attack each economically significant agent to maximize the return on health. PRRS virus control is no exception. With proper timing, producers can successfully vaccinate pigs against PRRS virus. A four-week lead time before exposure is important with PRRS virus to allow for pigs to develop an effective immune response. Use serologic evaluation to properly place vaccine ahead of challenge. Vaccines for Mycoplasma and PRRS can be given at the same time, or PRRS placed first, as is more typical on farms, with no interference.

When independent researchers evaluated the benefit of PRRS vaccination in pigs, a clear ADG benefit was noted. Iowa State researchers vaccinated pigs six weeks ahead of challenge. Those pigs that got a live vaccine had significantly higher growth rates compared to non-vaccinated pigs. Those receiving two doses of a killed vaccine did not perform differently than non-vaccinated pigs. A second study re-confirmed that vaccinated pigs are protected, and that vaccinated pigs could be evaluated with conventional diagnostic methods.

Placing controls

Timing vaccinations is key to provide sufficient time to develop immunity prior to exposure. Vaccines against all the major agents — viral or bacterial — should be placed four weeks ahead of exposure. Whether you use single dose vaccines like Ingelvac^® M. hyo and the Ingelvac^® PRRS vaccines (Ingelvac PRRS MLV, Ingelvac PRRS ATP), or traditional two dose flu vaccines, the first/only dose should be given to pigs four or more weeks ahead of challenge.

Strategic medication such as Denagard^™ Plus is timed to prevent clinical signs in the group. Strategic medications are placed when the first symptoms are usually noted, or when serology indicated exposure has occurred. These medications reduce the impact of clinical disease while allowing for development of natural immunity.

The complete package

Pig flow, site location, strategic medications, and vaccination allow for a custom respiratory health program to be developed. Combining production records and health evaluations (serologic measurement and slaughter evaluations) can objectively track the investment and return from improving respiratory health.

More information

Halbur PG, et al. Efficacy of a killed and modified live Porcine Reproductive and Respiratory Syndrome Virus vaccine when used alone or in combination in growing pigs. Proc Allen D. Leman Swine Conf. 1999. Pp. 29-30.

Yeager MJ. The diagnostic sensitivity of immunohistochemistry for the detection of porcine reproductive and respiratory syndrome virus in the lung of vaccinated and unvaccinated swine. J Vet Diagn Invest 14:15-19 (2002).

Boehringer Ingelheim Vetmedica, Study 6127-0004-99P-075.