Three cups the first day, then one cup daily for maintenance. Sometimes an extra cup every month, but only if the coat appears dull. You can easily tell if you overfeed because they become overactive and can only be distracted with shiny objects. Never underfeed. This will lead to unwanted behavior in living areas and they will whine during mealtimes.
Good luck. I could never keep one myself, but I heard they make great playmates.