Milk is an amazing food if it comes from the right sources. It should be from healthy grass-fed cows that are organically raised. If you buy milk from a store, buy from Whole Foods where you can get non-homogenized milk. If you can find a small farmer near you, buying raw milk is the best. It is full of amazing nutrition, digestive enzymes and healthy fat and good bacteria. Most milk, even "organic" milk comes from factory farms that have grain fed cows that are never allowed outside, they milked until they have mastitis and other infections requiring antibiotics. They are not designed to eat grain, so they are sick and bloated from their diet as well. The milk from a sick and unhealthy cow is not nutritious. The milk is full of pus, bacteria, feces and viruses. This requires pasteurization in order to be safe to drink and due to the contamination as well as the destruction of the digestive enzymes, many people cannot tolerate milk. In children it can be dangerous as it can cause bleeding intestines, that is why it is important to wait a year. We personally choose to drink raw milk or go dairy free.
If you would like to know more there are some wonderful books and sources online:
http://www.westonaprice.org/
http://www.realmilk.com/where4.html#or
http://nourishedkitchen.com/10-reasons-drink-raw-milk/
Recommended Reading:
The Untold Story of Milk by Ron Schmid
The Raw Milk Revolution by David E. Gumpert
Real Food: What to Eat and Why by Nina Planck
Nourishing Traditions by Sally Fallon
These sources will help you feed your child in a way to keep him extremely healthy as well as nourishing your entire family. It could change your life!