RE: 1,000 pound pig!
As an ex-hog farmer, my boars weighed from 800-900 lbs. My sows weighed 600-700 lbs. That is an auction scale not an estimate.
Yes this is a domestic breed probably a cross. If I had to guessed, I would say Duroc-York cross. I don't believe a feral hog can eat enough to get that size. There just isn't engough good nutrition available in the wild.
However we did have a black bear in NC that learned to raid a dead hog box. When they killed him he was 880 lbs. Even if the boar raided a corn crib, corn is only 8-9% protein. Maybe he raided a wheat or soysbeans storage bin.