That's some great experience, thanks. Fencing is hugely important, and even then, a momentary lapse can be costly. The north and west lines are fenced for cows by one neighbor, but I wouldn't trust it for anything else. After shopping on PremierOne I'm looking at the rolls of electric rope for the perimeter around all the paddocks, and doing three lines with that. Then use the portable pig fencing inside to form each paddock. I'm hoping that's enough.
I've even priced some GPS devices you can put on your pigs to help find them if they do escape. Not much for them to destroy at my neighbors, but the Ouachita National Forest is another neighbor and they could disappear in there fast. Don't want to contribute to the wild razorback problem Arkansas already has.
Breeding your own is the best way to make money, but I don't plan on trying that for a while. A few practice runs before that will probably help. Goats have been suggested by a few people, but I'd have to have people pre-pay for the meat like I will do with the pigs to want to take that chance. I just don't see many people making money from goats, but they sure would be helpful cleaning the brush out.
I had some experience with milk goats and pigs 25 years ago without electric fencing, the goats were major problems getting out but the pigs only got out once. But if it happens I might have to invest in those GPS collars.
I'll keep my eyes out on the classifieds and farmers markets for rabbit and quail, I don't know much about the profit potential from them. I do know rabbit poop itself is almost worth the investment for the fertilizer, but I'll have to learn more about breeding them. I don't have much population within a couple hours of me, so my market is pretty small and I'll have to look out for other opportunities like that.