I am starting to see a trend...
pigs need a special type of pasture...not the type you would raise cattle and horses on. they need to be able to have access to good foraging not forage...this means things like nuts, tubers, and the like...not grass. This is typically doen with sows and not market animals. The sows are let out while they are gestating but then brought up for farrowing because they have a tendency to roll on their babies. Many folks will keep them in lots and will feed them at bunks much like feedlot cattle...pigs can be very rough on pasture. Anyone that has experienced feral hogs wil ltell you about the damage they can do in a single night...I have seen hay meadows torn up so bad that driving across the min a 4-wheeler was not a fun experience