He's fine, and most likely growing at just the right rate for HIM.
There is not a single nutrient in cow's milk that children need that isn't also found in human milk (with the possible exception of vitamin D, which can be synthesized from sunlight exposure.)
There is not a single nutrient in cow's milk that children need that isn't also found in human milk (with the possible exception of vitamin D, which can be synthesized from sunlight exposure.)