As I understand it cattle tend to have it in the lungs and breathe out the infection, whereas badgers excrete it from just about everywhere - faeces, breathe, saliva, urine, pus from fighting wounds ..... They only have to pee and then a cow comes along the next day and eats the grass and there's another reactor 60 days later. I once enquired of the Moredun Institute how long it could remain infective on pasture and they said that in the right conditions it could be 6 months. If you're in an area like ours, where there are many small valleys, hedges and woodlands and the badgers will happily travel long distances to a maize field, digging under sheep fencing on the way, there's really not that much you can do. The conditions in a mucky cowshed may be ideal for coccidia, et al, but don't think that's going to have much effect one way or the other on whether a badger comes to call.