When you switch to Raw, your cat goes through like a "de-tox" period where it can either have constipation, OR the opposite...
If you ever go to straight Raw, you'll probably notice that his poops turn almost a whiteish.
The reason they poop less is because their body is using almost ALL the food. Unlike commercial kibbles where its all Corn and wheat that our pets DONT digest, so it allllll comes right back out.
Glad you're trying Raw!