@tsturm@angusm@cstross we do compulsorily mass test the herds, in the UK anyway. I have a set of BVD test samples I have to send to the lab tomorrow, from testing of this year's calves.
Whether we test for the right things is not a question I'm qualified to answer, but all cattle are compulsorily tested. I believe sheep and pigs are, too, but as I don't keep them I'm not certain.