Electric fencing is fine for pigs. We use 4 strands of 2mm high tensile wire, it's as cheap as chips. You can get a 200m roll for about a £10.
We have ours set out, 1st strand 4inches of the floor, second strand 10inches, 3rd 15inches and the 4th 20-25inches.
We have ours running off the mains so twigs and grass touching it causing earths dont affect the effectivness. At our old farm we used electric with batteries, there OK if you can guarantee no earth faults, the battery goes flat pretty quick otherwise.
Also pigs are very clever, If the battery is dead they will pretty soon cotton on and be away. They stand and listen for the click, when they dont here one they shuv each other into to test it!
We used to get about 5 days power from one battery, it can become a bit teadious swapping and charging all the time.
Good luck anyway!