How much [dog food] per day for optimal bodyweight?
This depends on the dogs eating habits and metabolism and age. A young dog (Under 2 yrs) will eat as much as 8 – 12 cups per day of a good dog kibble, a mature dog (2 – 5 yrs) may eat from 5 – 8 cups per day, a geriatric dog (over 7) should eat less and possibly a lower calorie less active blend. A Dane should not be fat nor excessively lean. If the ribs show this is probably too skinny, however an overweight dog is just asking for trouble. You should see a slight taper from the ribcage thru the loin to the hips (slightly wider than the loin).
