A dog food that is complete and balanced and includes at least 26 percent protein and 1650 kilocalories of metabolizable energy per pound is ideal. (dogbreedz.com)
I have not seen a figure for the maximum amount of calcium in very high energy foods but if a dog food provides less than 3.8 kilocalories of metabolizable energy per gram of food (< 3.8 kcal / g ME) then the calcium level in the food should not exceed 1.5 % on a dry matter basis. (vetinfo.com)
Because the Rubner and Atwater factors used to calculate metabolizable energy are not exact, the standard macronutrient values are not perfect, and small errors can occur. (mediatrendings.com)