You do realize that hogs raised in confinement are pumped full of antibiotics to keep them from getting sick due to the conditions in which they're kept right? They don't control parasites so much as they constantly treat for them. Commercial sows are penned up in farrowing crates because they tend not to be good mothers..... laying on their young is a trait that can be avoided through selective breeding, something the commercial growers are not concerned with because they "fix" the problem; hogs that put on weight in record time is their goal even if it means wallowing in their own feces while they feed their young or grow out to market weight. Piglets are weaned sooner in confinement operations so they can get the sows bred back in a shorter amount of time.... it sure isn't for the piglets' sake.
Hogs raised on pasture, using managed rotational grazing that defeats the parasite life cycle by constant moving from paddock to paddock and selectively bred for traits that avoid things such as crushing their young avoids everything you've listed above and makes for healthier happier pigs. Ignorance indeed.
I don't know where to start...........
Beginning with the first sentence most of this comment is blatantly false.