posted 12 years ago
It really depends on how many pigs, how big an area they have, and how "interesting" it is for them. We raise pigs each summer. Last time we had 4 of them on about 1/3 acre paddock that is partly grassland and partly forest. They loved the woods and spent most of their time there. Lots of things to dig up and it kept them so busy they never bothered to try escaping. One side of the fence was high-tensile wire mesh but the rest was simply wooden posts along which we strung 2 - 3 lines of electric poly tape (the lower wire could be removed when they got bigger). They got zapped once or twice as weanlings and that was it, they kept away (except for the day the electric went down and they tried to wander onto a fresh pasture but we easily lured them back with feed).
I think it's because we have few pigs in a big area and there is lots for them to do - roots to dig, mud to wallow in, an area full of salmonberry bushes that they seemed to love making tunnels through...