Predicting risk of vertical spreading and horizontal shedding or MAP using a Bayesian algorithm that accelerates detection of Johnes Disease (JD) in dairy cattle

In this trial we have shown that by including information on the cows (age), their dams (JD status), and test detail (linear S/P ratio) we can predict better whether or not cows test positive for MAP in their dung. There is also suggestion that the dam status could be relevant in the passing on of MAP infections, as cows out of milk ELISA positive dams and with increasing probability of infection are more likely to test positive for MAP in their bloodstream with the Actiphage test. There are some caveats that need raising, in that the sample is relatively small regarding the number of cows and the number of farms in the trial, this makes extrapolation to other farms more difficult and requires a much broader range of farms in the sample.