Wild boars - big and small, prefer carrion.
A customer asked me if my pigs are fed a vegetarian diet. I explained that they aren't - because the best way to take care of little pigs is to make sure that they get the animal protein they need to develop well. Of course, pigs being fattened for slaughter have entirely different needs (even though they fight over meat).
I've written about this before. The reason I bring it up yet again is that in the course of doing nutrition research, I came across the following studies which suggest that denying weaner pigs animal protein (to please certain customers) could be bad for the pigs' health - just as traditional outdoor farrowing leads to unnecessary mortality:
Influence of a Vegetarian Diet Versus a Diet with Fishmeal on Bone in Growing Pigs
The effects of spray-dried blood meal on growth performance of the early-weaned pig
Pigs wag their tails when chicken is for dinner.
Most consumers who say they want vegetarian pigs probably don't know how unnatural vegetarian diets are for pigs. If they knew how denying piglets animal protein can hurt the piglets' development (without making humans any safer), they'd probably start insisting that piglets be fed appropriate (and traditional) nutrients like cooked chicken heads.