Puppy won't stop chasing cats.

We got a five month old black lab puppy and some barn cats of varying kinds. They don't get along well. Our puppy loves to chase them, and even when I let him near them and he's somewhat nice to them, our orange cat swats at him. In addition, he loves chasing after and trying to chase after and eat wild animals. I keep trying to pull him away, say "no" and "leave it" as I'd trained him to leave treats on command, but animals are different.

Any advice for quelling this behavior?