As a pig owner myself, I can say that it helps to keep them contained so they cannot forage for grass & other comestibles until presented with the body...

If you want a pig to eat something, you just chop it up & mix it into a few meals so they recognize that as food.

Feed them fingers & toes a few days & they'll gobble down that body!

I proved this with cannabis. fed them leaves with their other feed & they left it.

Then I made a hot mash with the chopped leaves in it & they ate that.

Soon, they'd eaat the leaves from my hands.

Now, it's Mama Pig's favorite food.

You can train a pig to do anything!