I would limit their pellet food to 2 tbsp per day for each adult chin, half that for babies. Pellet food is good for them nutritionally, but it can cause dental problems. When they chew hay they move their jaws back and forth like a cow. This helps keeps their ever-growing teeth ground down to the right length. When they chew pellets they move their jaws up and down like a dog, so their teeth aren't getting ground down. That can lead to points on their teeth, which can be painful and interfere with their ability to chew comfortably.
As far as hay goes, I always say they can have as much as they want. Hay is great for their teeth and their digestive system.
