There’s increased interest at the commercial level in closing herds to gilt introductions, says Rick Tubbs, DVM, Bowling Green, Ky. In some cases, the goal is to close herds to all animal introductions. The potential health benefits of closed herds is driving this trend. He cites some of the benefits here:
1. Animal introductions are the most likely route of introducing new or different disease organisms into a herd.
2. Transport errors and contamination present a risk. Animals negative for specific diseases may be loaded onto a truck, then become contaminated in transit. A no-animal-introduction policy means that exposure risk is removed.
3. Replacement breeding animals raised on site are well acclimatized to endemic herd organisms if exposure is handled properly during the gilt development period. In contrast, outside-source animal introductions may require long isolation and acclimatization periods, depending on the health status of the source herd and the recipient herd.