I'm sorry. Your son's doc is off his rocker. That is a lot of whole milk for a little baby.
"Cow's milk is not recommended by the American Academy of Pediatrics for children under 1 year old. Infants fed whole cow's milk don't get enough vitamin E, iron, and essential fatty acids. They also get too much protein, sodium, and potassium. These levels may be too high for the infant's system to handle. Also, whole cow's milk protein and fat are more difficult for an infant to digest and absorb."
From this website:
http://www.nlm.nih.gov/medlineplus/ency/article/002448.htm
Breastmilk or formula is primary nutrition for the entire first year. It is a complete food, easily digestible and his body is able to process either far better/easier than cow's milk.
Neither of my breastfed babies got whole milk till they were 13-14 months old and then it was gradual. It's not a "bam" they are 12 months old time for cow's milk thing. It's much harder on their system as you can see from the above article. I made the transition slowly and gradually.