Nutrition for large dog breeds has its peculiarities and you should never confuse nutrition for these giant breeds with the one for tiny dog breeds.
Dog nutrition for large dog breeds should be based on the specific needs of these breeds. One of the first things to take into consideration when choosing the proper aliments for a Great Dane, a Labrador Retriever, a Boxer, a Weimaraner or any other large dog is the fact that these dogs normally show several joint and bone complications and that the food they are provided with should be prepared to relieve the stress and pain they feel around the hip or the elbows.
You must remember that large dog breeds are always active and require lots of exercise so providing them with a high on protein nutrition that allows them to function properly is the best idea. This nutrition should also include cereals (except corn and wheat which are hard to digest although large dog breeds have large stomachs), dairy products for the bones and a nice combination of fruits and vegetables.