Feeding nursery pigs a standard regimen of Tylan Premix for the prevention and control of ileitis did not impact their immune development.

In a trial overseen by well-known ileitis researcher and Minnesota veterinarian Nathan Winkelman for Elanco Animal Health, a group of 120, 20-lb. pigs were divided into four treatment groups in two nursery facilities.

Two groups were challenged twice with Lawsonia intracellularis, the bacterium that causes ileitis. Despite the two challenges, pigs fed Tylan at 100 grams/ton for 21 days experienced no impact to their immune systems.

According to Elanco veterinarian David Bane, there were no significant differences in immune levels between treated and non-treated pigs.

There were differences in performance, however. Pigs receiving Tylan at 100 grams/ton for 21 days grew up to 17.3% faster than challenged, non-treated pigs. Treated pigs ended up weighing 10.5 lb. more and achieved a 38.5% better clinical impression score for diarrhea than the non-treated pigs.

Questions have been raised about the role of antibiotics in precluding the pig’s ability to develop immunity. "Tylan used at 100 grams/ton for 21 days did not influence immune development as measured by circulating antibody," says Bane.

Tom Marsteller, Elanco veterinarian, says producers and veterinarians may also need to rethink the role of the immune system when it comes to ileitis. "Without a strategic prevention protocol in place, pigs can develop ileitis several times throughout their lifespan because the duration of protective immunity is short with this disease. Producers may pay a heavy price in performance and pig variation for the development of immunity without adequate protection," he says.