Virginia actually has both fence IN, AND fence OUT counties. Our county of Rockbridge is a fence out county. The one directly north of us is Augusta and it is a fence in county. We have rented places in both counties. That said, with the value of the livestock, it makes sense to keep them contained behind a fence. But as long as they are on our properties, rented or owned, no one can say anything. Since the one farm borders the interstate.... just south of the Rockbridge county line, the VDOT is responsible for maintaining the fence along the interstate to keep the animals out. Still, things happen, and we try to be diligent to keep the fences up so the animals stay put. Unless an animal has an identifying eartag or brand or tattoo or you personally claim it; in Rockbridge county if it causes say an accident, and no one "claims it", they cannot assign blame to the closest landowner. It can get sticky... I look for all counties to go fence in except maybe the most remote ones. In Highland county, west of here, they actually have cattle guards in the county roads... if the landowner owns both sides of the road, to facilitate grazing and such. I think it is a great idea. However, here the people drive too fast and we are slowly losing the ruralness that used to define many of the dominant agriculture and more remote western counties.
We also carry a big liability policy due to rented and leased as well as owned land, with the animals being here and there during the grazing season... and with the interstate so close, and with all the citiots moving out here and if a cow gets out, someone hitting it is just a nightmare....or damaging someone's fancy planted / landscaped lawn and all the expensive shrubs....
Animals that are trained to and respectful of good hotwire are less likely to get out and cause a problem than those that are used to a barrier type fence (woven wire field fencing, barbed wire, even board fencing) say if there is a windstorm and a tree takes down a part of the fence....or like us, a stupid driver goes through the fence or the idiot that took out the corner post and tore down the section of fence with the back end of the tractor trailer/tires.... because they will be more respectful that the fence could "jump up and bite them" even from the ground.... A mvisual barrier fence that has a hole in it is an invite to get out the hole.....
Still I would want a good barrier, woven wire or board fence around my perimeter ..... electric is fine for cross fencing and to reinforce another fence......