Stochastic simulation models are widely accepted as a means of assessing the
impact of changes in daily management and the control of different diseases,
such as paratuberculosis, in dairy herds. This paper summarises and discusses
the assumptions of four stochastic simulation models and their use in the design
of certification, surveillance, and control strategies for paratuberculosis in cattle
herds. A detailed comparison is made between the Dutch JohneSSim and the
Danish PTB-Simherd, using the same context of a set of control strategies in a
typical Dutch/Danish herd. The conclusion is that while the models are
somewhat different in their underlying principles and do put slightly different
values on the different strategies, their overall findings are similar. Therefore,
simulation models may be useful in planning paratuberculosis strategies in dairy
herds, although as with all models caution is warranted when interpreting and
generalising the results.