Lucky....A question about Johne's disease..

[jasonleonard]

Some of our local amish dairy farms have converted to produce production, and some have nice parcels of pasture for rent for next season.
A large number of the amish dairies around here are known to have Johne's in their herds.
Would the risk be too great to run some pairs or stockers on these ex-dairy farms, or would we need to wait 5 years or so? Or, Are they contaminated forever?
Thank you in advance!

 

[Lucky_P]

The Johne's organism can persist in the environment - particularly in manure pats and moist soil (like around water tanks/feed troughs, etc.) for over one year.

Stockers - not a problem; especially if they're steers - someone's going to eat them long before they develop clinical disease, even if they became infected.

Pairs - guess I'd feel better if a year or more had passed since the dairy cattle were in residence, but the older animals are, the less likely they are to become infected. Studies suggest that it takes a pretty significant level of repeated or constant exposure to infect a mature cow.
Calves are most susceptible, and beef calves born to JD-infected cows are 10X more likely to be infected than calves born to non-JD dams in the same herd. Beef calves' principal exposure, in most cases, is from the dam - at least 25% of calves born to Johne's-infected dams are infected prior to birth, and infected cows shed organisms in colostrum/milk as well as feces.