Here are a few of the most intelligent pig breeds:

Miniature Pigs: These small pigs are often compared to dogs in terms of their intelligence and trainability. They are known for their quick learning abilities and can be taught a variety of tricks.
Vietnamese Pot-Bellied Pigs: These pigs are also highly intelligent and can be trained to do tricks, walk on a leash, and even use the toilet.
Berkshire Pigs: While primarily known for their meat, Berkshire pigs are also known for their intelligence. They are quick learners and can be trained to perform various tasks.
Duroc Pigs: Another meat breed, Duroc pigs are also known for their intelligence and trainability. They can be taught to follow commands and perform simple tricks.
It's important to note that intelligence is not solely determined by breed. Each pig has its own unique personality and learning abilities, influenced by factors such as environment, upbringing, and individual temperament.