Cow's milk is allowed to have feces in it. This is a major source for bacteria. No wonder milk turns rotten very quickly. The cholesterol content of those three glasses of milk is equal to what one would get from 19 slices of bacon. Lots of it.
Mother nature knows better.
Ten years ago, scientists learned that IGF-I was an identical match in the cow's body and the human body. Everything gets concentrated. Steroid hormones survive, as do dioxins and antibiotics. Each of those hormones and proteins acts differently and has different rates of degradation. In order to absorb calcium, the body needs comparable amounts of another mineral element, magnesium.