to factory farming are actively suppressed:
Free range hogs were an economic mainstay historically in much of the US,
especially in the Appalachians and Ohio Valley. Typically, a small number of
animals were kept in confinement and fed during the winter then released
to run free in the forest, fattening on the then-abundant mast. Ownership
was kept track of by a system of cutting notches in the animals' ears.
In the fall, the pigs were rounded up, the bulk of them slaughtered or sold
and the whole process repeated. In Spain the highest quality ham is considered
to be from hogs finished on acorns (jamon de bellota - "bellota" being acorn).
Kind of hard to see how factory farming is any kind of improvement on that.
Good article (and excellent site) here: