We have black angus cows in the pasture behind our house. They eat all the leaves off the trees that they can reach and also are hard on the bark just like your pest. The only plant in the pasture that they don't bother are the blackberry briars. I guess that they don't like getting stuck.I had to put chicken wire around my new trees that I planted. They were eating the limbs off the bottom of the trees, and then tearing the bark off the trunk rubbing on them.