Your Boxer is totally reliant on you for this food. This is a big responsibility for you as a Boxer parent. Your Boxer can not go out and purchase food for himself, or hunt for himself, so it is totally up to you to provide good nutritious food for him. You will have to ensure that he does not get too fat (having an obese dog is a form of cruelty) and you will have to make sure that the calorie intake meets the amount of energy he expends or he will be too thin. A lean muscular Boxer is a joy to behold, so you need to make sure you are meetings his needs.
Regardless of what you eventually choose to feed your Boxer, it is always best to follow the breeders feeding program when you bring your new puppy home. A change of diet at this stage will cause tummy upsets in your pup. If you do decide to change the feeding program, do so very gradually, slowing introducing the new food mixed with the original food. There are as many ways to feed a dog as there are people in the world! It is up to you to decide what is best for your dog as an individual. Remember too, that what type of food suits one dog could be totally wrong for another.
One of the most common ways of feeding a dog is with a good quality commercial kibble. Click here for how to choose a good kibble.
There are numerous brands, all offering different things, and suited to many stages in your Boxer's life. Not all brands suit all dogs.
There is also commercial canned food, which some people like to mix in with the kibble. If you choose to feed commercial food, look carefully at all the ingredients and try and choose one with as few preservatives as possible. Many commercial foods are now preservative and additive free and also use organic ingredients.
Another way of feeding is to NOT feed any commercially prepared dog food at all, but to provide your dog with a totally 'natural' diet or to home cook. Raw, natural diets are now commonly known as "BARF" diets, which stands for Bones and Raw Food. The idea of these type of diets is to try and replicate the type of food you dog would eat if he was still in the wild. More and more dog owners are feeding this way and having great success with it. It is not a good idea to feed a BARF diet until you have researched it and understand the principles. Two very good books about BARF diets are "Give Your Dog a Bone" by Dr Ian Billinghurst and "Grow your Pup with Bones" also by Dr Ian Billinghurst.
Regardless of what you feed your dog there are a couple of things they should never eat. Onion (raw or cooked) and Chocolate are toxic to dogs. Care should be taken too with milk as many dogs are lactose intolerant and feeding milk can cause severe diarrea with some dogs requiring hospitalisation. If you do want to feed milk then you could use goats milk, preferably fresh. All dogs, regardless of diet, enjoy a nice big RAW meaty bone to chew on a few times a week. These raw bones are great for teething puppies and wonderful for keeping an older dogs teeth clean. Never, ever offer you dog cooked bones as their stomaches are not designed to digest cooked bone, and cooked bone will also splinter when chewed. Cooked bones are extremely dangerous for dogs. If your dog looks good and is happy and energetic, then you are feeding the right thing - well done!