The pigs were domestic, raised by our neighbor down the road. I shot them once in the head and then stuck them with a long knife down through the neck and into their heart causing them to bleed out very fast. It takes less than 10 secs. Then we hang the animal by it's hind legs and wash it off thoroughly with soap and water. We skin it, gut it, quarter it, and then place it in a freezer. Wash rinse repeat.
We don't kill the cows anymore, just take them to the local locker to have them killed and aged for 5 days in their freezer. When I was little we used to kill the beef in the dead of winter and hang them in the shed because we didn't have a large walk in freezer. Later in the week we made a big fire to heat a huge vat of water to scald the pigs (after killing them) so we could scrape the hair off and save the skins to sell to the locker along with the cow hides. We also rendered the pig lard for cooking so there's that too. I don't miss those days.