How long can Johne’s stay in my pasture?

It varies greatly on the situation.

Factors that can affect the prevalence of the organism include the amount of sunlight, thawing, freezing, and moisture. A large amount of organisms die in the environment after a few months. But it's also true that some of the organisms shed can live for up to a year in the soil.  This is why it’s advised that kids are kept off pasture with possible contamination for a year after a case is found in your herd.

The organism can still be present after a year, but it’s not present in levels that would lead to infection. (Assuming all infected animals have been removed and the herd is clear) When considering your risk for Johne’s you are more likely to buy another animal that is positive and have that animal spread it in your herd then you are to have your existing animals infected by their environment.

Quick Note about Ponds:  It has been noted that the organism can live longer in ponds or areas where water collects in the pasture. It is recommended that you keep kids away from ponds and from drinking water that could be contaminated by run off.