Every dogs methabolism works a little differently. Many aspects influence this. Environment is one big issue. It is impossible for anybody to give exact feeding amounts to any breed of dogs. Even within a litter, there are considerable differencies in the utilization of nutrients from a diet.
All breeders know the importance of the balance between calcium and phosphorus.
However, many breeders do not follow the daily feeding amounts. Calsium and phosphorus values on the bag of food are given as percentages. This is one of the reasons for imbalances and arises from improper feeding amount. Never supplement with calsium on an industrial feed. Calsium is one of the cheapest rawmaterial, so one can be assured that maximum amount are in the bag.