We still use a "conventional" rototiller to put a finish on the garden, but pigs do many things for us to prep that soil. Pigs go into the garden at the end of the season. I rarely bother to clean up much of anything, just open the gate and say "Here you go". They spend a couple of weeks really gleaning every last morsel left behind!. The roots, leaves and stems of almsot every plant are devoured.....and if not devoured they are unceremoniously tilled into the soil. I have in the past (this year I'm thinking I might try rabbits) used old "goat hay" to mulch the paths in my garden. This is tilled into the soil as well by the pigs. Throughout the winter the buckets from under the rabbit cages are added around the garden....again tilled in wonderfully. When spring arrives they dispatch any early emerging bugs or weeds while also loosening up the soil. The pigs tend to leave areas of their own waste undisturbed however. They also leave behind a few deep holes which is why we remove the pigs in spring and do a quick once (or twice) over with the rototiller.
An electric fence system works very well with pigs. We have only a lightweight fencing around our garden. It is mainly in place to keep the free range chickens out as we don't have to many large garde predators that get that close to the house. We just run a strand of electric fence around the bottom and the pigs don't bother trying to get out.
Here is a link to see the progression going from day one to day 24.
If you have crops you plan to overwinter in garden (for example parsnips) that area MUST be blocked off from the pigs.
If you have rain collection apparatus in your garden you may need to remove it to prevent damage from curious pigs. Ours will tip over the barrels, but since we have to empty the system every year to prevent damage from freezing, moving the system isn’t a big deal.
If you have any type of a permanent sprinkling system, you may need to rethink using pigs.
We did tend to get a lot of volunteers when trying to feed the pigs unsprouted grains. Unsprouted grains are not recommended for pigs as a sole diet for this reason....they can't digest most of them. A pig can starve on whole grains.
If you use raised bed boxes or any type of containers....remove them.
Since this will be our first year (2014) trying to use a rabbit tractor or tunnel system as a means of weeding our vegetable garden I don't have any photos and have only minimal information (just notes really) on the "how-to".