[MarkusWandel]

I should clarify that I'm thinking like an old-school dairy farmer here, because I did grow up on a dairy farm. Cows were confined to the day's grazing area by putting up lightweight electric fencing. Just sticks of wood hammered into the ground with an electric insulator on them, and wire strung between them from a reel. That's how we did it; more modern version uses metal or fiberglass poles and a soft string that has wires woven into it.

The shock from the fence was mild, but the cows knew about it and respected the fence. And when the area was grazed out, you moved the fence and gave them a new area. Any "right to roamers" that wanted to cross the field could easily duck under the fence. No problem. Mind you, this was in rural south Germany, not urban Britain. We did get right-to-roamers, sort of, because there was a somewhat popular swimming access to a small lake on our pasture.