Dr. Damien Barrett:

To be clear on this, we are talking about high-risk herds plus high-risk animals within high-risk herds. Without breaking confidences, this revolves around animals that are cohorts of reactors. These are the high-risk animals. In effect, they are cows. If the cows are the high-risk animals, the calves would not be considered as high risk. We could see a scenario where there are controls on the movement of cows out of herds but not controls on the movement of calves.