I had a thought on having a lioness/lion to a favorite food and it gives the lioness/lion a small mood boost. For example if a lioness/lion's favorite food was zebra and you feed it to them they will gain like a 2% mood boost. But if the food isn't their favorite food they don't loose any mood it just stays regular like how they get fed now. So you would have to figure out what food is the lion/lioness's favorite if you want a little mood boost.