A few different farmers have reported that Mangalitsa sows fight longer, harder and bully each other more.
One night some sows turned on one sow, killer her and ate most of her. It was like a horror movie. It isn't clear why they did this; the standard answer would be, "they are pigs."
There's a sow that can't get up, because the other sows had somehow hurt her back. She's been on her side for days. She can eat, crap and drink, but can't get up. She had been alone with four other sows until recently. They turned on her and hurt her. We think they hurt her back, perhaps by riding her. She also had some bite marks - but that wasn't why she couldn't get up.
I also have a boar that got hurt recently. Two boars that normally get along were in a pen together. One of them started riding the other, trying to rape him. The boar on the bottom tried to get away. In the process, he hurt his back. He hasn't been able to walk much since. That means he can't work. He was worth a lot of money - now we might just euthanize him.
In all cases, we've got productive animals that have been hurt by their peers. They are either dead or injured. The injured ones may not recover. It disrupts production. If they have to be replaced, there's a cost to it. Just providing the injured animals with special care costs a lot more than caring for the others.
Clearly, the farm wasn't designed with the needs of the bullied in mind. Nor is the farm designed in the interests of rewarding the just and punishing the guilty. It reminds me a bit of kindergarten. The teacher doesn't care why the kids are fighting, arguing or bullying each other, or which kid is in the right, and which in the wrong. The teacher just wants it all to stop.
There's an interesting video that explores the problem of housing and bullying. Having seen how brutal and cruel pigs are, I can see why most pigs are housed individually.
Pigs don't behave in accordance with their situation. They aren't in the wild fighting for food. They live on a farm and there's always extra food - we see to that, because we want them to get big and fat. But still they fight, and take pleasure denying food to each other - a bit like this dog.
Of couse, the longer animals are domesticated, the more time humans have to impact them. These pigs are probably the most domesticated. They don't move around much or bite humans often.