I think Dr. Cordain's first statement was misunderstood. It seemed to me that he was talking about the estrogens that are in milk naturally, not from exogenous sources.
Raw milk producers and other dairy producers all use the same basic production cycle. The milking cycle begins when the cow has her calf. 60-120 days later the cow is impregnated. Milking continues for the first 7 months of gestation, and the cow is "dried off" (milking stops) for the last 2 months of gestation. This means that for 60%-80% of the milk production cycle the cow is pregnant. The pregnancy is the source of the estrogens Dr.Cordain was referring to.
