If you think pigs are bad with the environment, watch until you see the environmental damage that goats do. They literally graze everything to the ground. They fatally wound most trees. They leave behind desert.

Pigs (especially older breeds) do basically the same thing and will also go through the extra step of finding and eating roots.

There's a reason a pen containing goats is typically thought of as a pasture whereas a pen containing pigs is generally thought of as a mud pit.