Dr. Walter Veith speaks on how the Galactose and Caseine can cause infertility in men and women. The sperm become deformed. Sometimes they get a bump or a kink in thier tail. This can cause the sperm to loose thier efficiency in swimming straight. And they can also become slowed from the bump and the kink in thier tail. It can also lower the total sperm count, the size and health of the sperm. The life span of the sperm can also be decreased.
Source: Consumption of Dairy Causes Infertility In Men