How far from the farrowing house must the nursery be to limit disease? The consistency of your biosecurity system may be more important than site distance.

In a trial, veterinarian Tom Fangman, University of Missouri, found that on-site nurseries can be as free of disease as off-site nurseries under the right conditions.

The farm used in the trial had a good herd health status, Fangman says.

“The primary pathogen concerns were E. coli in the farrowing house and Strep. suis in the nursery,” he notes.

Operators adopted a strict biosecurity program for both on-site and off-site nurseries. The results showed no difference in the nurseries. Both units suffered the same degree of Strep. suis challenge, but no other pathogens affected the pigs.

“The point is strict biosecurity on the farm in a high-health status environment can be as effective as taking pigs off site,” Fangman points out.

Another part of the study looked at how weaning age affected nursery pig health. Pigs weaned later than 16 days tended to present fewer health challenges and post better growth rates than those weaned earlier.

Fangman speculates that pigs staying in the farrowing unit as colostral immunity declined to 20 days of age may have been exposed to low levels of pathogens that primed their immune systems. It let them get accustomed to low levels of those pathogens.

The super-immune pigs weaned at less than 15 days didn’t have the same immune response and so, when exposed to pathogens in the nursery, took longer to develop immunity and overcome the challenge. Growth rates suffered.

Fangman will continue research on the links between weaning age, health status and immunity.