We put up a new fence using bi-polar fence tape and a solar charger. It uses the horse (or you or whoever touches it) as the ground so its just as hot when it's dry out as when the ground is damp. It must really bite because the horses won't dare get close it and my husband no longer tests it by touching the tape. We just have 2 strands out and spaced the t posts 16 feet apart and the top strand is run through a t-post topper with a holder for the tape. Google "bipolar fence" and you'll find the the company that makes it.
Posts: 1314 Location: North Central Iowa Land of white frozen grass
Just for your info. Here in Iowa. The Gov. has programs that will pay for all the internal fences and water if it needs it to be used in rotational grazing. I think that this is a federal program. Go to your local county ASCS or conservation office and ask about the program. You have to get it approved before you do any fencing. They will not pay for the perimiter fences.