They need to test the cows before they can cull them? If they plan to eradicate M.Bovis, I suspect it will take a decent period of time, with associated tests and culls. From what I have read, it sounds like the program will be much larger than the previous cull, in which HRL held the contract to do the M.Bovis testing (they still need to win it/be chosen as a preferred supplier this time round though).
The meth report does raise some questions/risks to future growth to that part of the business, but I think you back the management to grow other areas of the business (I.e. dairy, honey, timber, enviro as well as expanding into Australia) and potentially inorganic growth through acquisitions.
What are you basing your 10c re-rating off? I think what it is currently trading at makes sense to its listed peers.