I had a pig in a cage and had another dog bark and they just walked around and didn't act interested
Get the pig out of the cage and get their attention. When they perk up drag it away from them and stop. Let them feel they are chasing it. Lay it down and let it squeel a bit then drag away from them again. If they are gamey they should take to it Perty easy and begin baying. Then take advice from Brad W from above and keep em wanting more.