Eventually I want to forest raise pigs on 10 hectares in the tropics. The "orchard"/ food forest I want to integrate them into will be full of coconut, macadamia, mango and avocado as well as ice cream bean and a number of other tropical fruit species.
The problem is, I have no experience with pigs. I figured they could eat fallen fruit, but I really don't know anything about them or what damage they will cause or how to keep them from escaping.
Hi Windy! I live in Hawaii on Big Island, so I guess that makes me officially in the tropics. And I keep a few pigs. But I don't have quite the experience you are looking for. Presently I have 2 pigs living in a 150' by 100' enclosure. And 3 feeder pigs living in a smaller pen. And while I raise almost all their food on my farm (I do forage some and have some given to me), I do have to bring their food to them. The enclosures are too small for them to do much more than nibble grass as a snack.
A pig eats quite a lot of food in one day if it is not being fed a concentrate, such as commercial pig feed. Each of my adult pigs eats 5 gallons of pig slop which is a wide assortment of foods cooked together into a stew consistency. It takes quite a lot of fresh foods to make that volume. And while some pigs will graze grasses, mine barely nibble the grasses in their pasture. Even if hungry they will scream for food, scrape bark off of the trees, dig up the tree roots, but still not eat the grasses.
I really don't know how much acreage of a food forest is needed to maintain one pig. But I suspect you won't be able to keep too many on 10 acres without supplementing their diet. Pigs can be rather destructive, so unless you break that 10 acres into 10 one acre paddocks, it wouldn't be long before they destroyed the forest. Some pigs will root aggressively while others will not. But those that do root can easily kill all the ground plants, bushes, and even trees. As I mentioned, they will scrape the bark right off a tree, girdling it.
I don't think a pig can open a coconut, but they do indeed love macadamia nuts and mango. They will also eat sone avocado. There are plenty of other tropical fruits that they also will eat. But most tropicals produce fruits seasonally, so you'll have to research their harvest times in order to stagger when they produce edible food.
As for escaping, they can be pretty good at that! The smaller the confinement pen, the more they will try to escape. I've never tried training a pig to an invisible fence, so I'm not sure it can be done. But keep in mind that an invisible fence doesn't keep out predators, such as feral & wild animals, dogs, and people. Pigs can be confined with a field fence combined with a strand of hot wire. That deters most predators and keeps the pig in. Premier Fence 1 makes a movable electric fence for pigs that would work to move the pigs around, or you could just section off areas using 2 strands of hot wire. Personally I prefer using field fencing and one hot wire strand. I have problems with feral dogs who aren't controllable with hot wire by itself.
I'm in the process of creating a two acre rotational pasture system for my pigs. I'm breaking it into half acre paddocks. After they move off of one paddock I plan to replant the bare spots with oats, sweet potatoes, and other edibles, thus giving it time to grow until the next time they return to that paddock. I'm hoping that they can stay in each 1/2 acre paddock for a month before moving on, but I don't know yet if that is a realistic time period. I fully expect they to pretty much destroy the paddock, thus requiring replanting. Since I have access to a lot of annual food plant seed and cuttings, I don't mind the idea of replanting. That way I can provide them with a varied diet. I plan to still feed them some slop daily so that I can include foods that they wouldn't get in a food forest/pasture (bananas, meat, rice, etc) and have an easy way to get medication into them when needed....and keep them friendly and coming to me when called.
It's never too late to start! I retired to homestead on the slopes of Mauna Loa, an active volcano. I relate snippets of my endeavor on my blog : www.kaufarmer.blogspot.com