My 9 year old and I did it last March. Think about it as a photo op. You take a little metal skiff for about a 5-10 minute trip to the "pig island." They give you instructions and when one group leaves, they let you go down to the beach. and the pigs are roaming about. They have a couple of the big pigs that you wait your turn and then attempt to hold onto while they swim toward camera. Then they have piglets that you can pick up and hold. The pigs do poop in the water and there are guys with nets that fish it out. If you don't want to swim with the big pigs, you can still stand ankle deep on the shoreline and feed the pigs. They have a few guys taking photos but they also let you take photos yourself. When you get home, you can go online and look at their photos if you want to buy. They were relatively reasonably priced.
As I said, it was more of a picture taking opportunity than active excursion but my 9 year old really had fun interacting with the piglets and we got really cute photos. It only took about an hour and a half so plenty of time left on our day. There are some youtube videos of others trips there.