Topped a newly rented field today with the disc mower. There was the odd ragwort through it. If I put 18 month beef cattle in it for the next two days will it do them any harm? Surely the ragwort will still taste crappy so they'll eat the mown grass? If they're going at two years old does it matter if they have damaged livers? Probably stupid questions but I've never dealt with ragwort before.