we have them at our zoo you mean pot belly's correct?
A pellet food called mazuri is good here is a link
shop.mazuri.com/mazuriminipigyouth.aspx
Also you can feed a variety of fresh vegetables to make up about 25% of the pig's diet.Celery, cucumbers, peppers, carrots, potatoes and some greens are good choices (but try to limit the starchy vegetables like potatoes). Some fruits can be feed as well but only in moderation due to the high sugar content. Most pigs love treats like apples, grapes and raisins, but these are good to reserve as treats to be used in training. They train pretty easy haha they are actually pretty smart :P
some extra fiber can be provided by feeding hay we use Alfalfa.
Also here is a link that has a little more info i just googled that but the rest is from working at the zoo hehe im in a bit of a rush but goodluck!!