our state DOT has rented goats to clean the sides of roads along highways in some rural areas, especially when there are large amount of noxious weeds. The person they hire strings up a bunch of short fiberglass poles for a mile or two along the highway with some wires, puts out some water, and then lets the goats in. Comes back and picks them up a couple of days later, and moves them to the other side.

Goats LOVE poison ivy and oak, and it doesn't hurt them. Don't let them near hemlock though (it will do the same to them as it did Socrates)

They seem to like Scotch broom as well. Some red-leafed garden ornamental is brutally toxic to them though, and it can be a slow, agonizing death.

Not just some wire but a portable electric fence.