We spent all season with the pigs trained to and confined by electric fence, moving them to new ground by opening up new areas and enticing them in with food and fun. And lots of patience. After the first time, they never seriously tested the fence, only touching the electric a couple times during moves when they got confused (pigs don't see very well), or by accident (which we've done ourselves more than once.)
But we don't own a livestock trailer so when the time came to get the pigs to the processor we elected to hire a rented trailer (paid by the hour!) and ask the pigs to cross through a hole we made in the electric fence (new concept to them) and step up (which they had never done before) into the trailer (a strange new place) in order to get food in the trailer (but there were still some things to root up in the pasture enclosure). In order to get the pigs to go the direction we wanted as quickly as possible we decided to embark on a process of rapidly condensing their pasture so that the walls of the electrified fence closed in on them into a tighter and tighter space with the electric fence surrounding them and closing in tighter and tighter, their only escape being the strange and unknown trailer. Or crossing the electric fence.
This was not a wise decision. Also, we can testify that if you train them to electric, treat your pigs really well and give them plenty of space and fun stuff to do and unlimited food and water in their pasture, they will not cross that electric fence unless you, the farmer, are really, really, really stupid.
And that's why we didn't end up cramming the pigs in a trailer to harvest them in November but instead harvested on farm in December with Lonestar, a local mobile livestock harvest small business. We're also switching to a different type of electric fence that doesn't cost over $100 per easily-destroyed section, and will recycle our current electric setup (after repairs) for some other exciting uses to be announced soon.
This was a very valuable lesson for us. In the additional month the pigs gained quite a lot of weight. We aren't happy about that, because it means they finished over the ideal size for our customers. They also ate a lot more food -- far more food than they made up for in weight gain.
This was a painful, stressful, but useful lesson to learn. At least it wasn't painful or stressful for the pigs. We are big fans of mobile livestock harvest now.