At that age daily nutrition is more important since they are still growing.
Dry cat food in very small quantities can help with protein. Any table scraps from your meals as well as greens like cabbage, kale, broccoli, and other veggies are acceptable even if not a complete feed.
They will...
How old are they?
They should be kept cooped for several days until they know that's where to sleep before free ranging.
What's your climate? Do you have lots growing right now?