Though it may take several months, they usually they go away on their own. Some people use pliers to squish them and this triggers an immune response in the animal (they also feed what they trim off to the animal, but I don't think that does anything). If the warts are affecting the steers' vision or they are show animals, then you might need to get the vet involved.
You can google "cattle warts" or do a search here on Cattle Today and get a lot of information.