The human body has no more need for cows' milk than it does for dogs' milk, horses' milk, or giraffes' milk.
Michael Klaper, speech of July 19, 1985. Quoted in David Robinson Simon, Meatonomics (San Francisco: Conari Press, 2013), p. 193
You cows that I see before me, how many thousands of gallons of milk have you given during this last year? And what has happened to that milk which should have been breeding up sturdy calves? Every drop of it has gone down the throats of our enemies [the humans].
Cow milk has no valid claim as the perfect food. As nutrition, it produces allergies in infants, diarrhea and cramps in the older child and adult, and may be a factor in the development of heart attacks and strokes. Perhaps when the public is educated as to the hazards of milk only calves will be left to drink the real thing. Only calves should drink the real thing.
Frank Oski, Don't Drink Your Milk! (Brushton, NY: TEACH Services, 1996), p. 84
Civilized men know the art of preparing nutritious foods from milk. For instance, in our temples and monasteries we make hundreds of first-class preparations from milk. Whenever visitors come, they are astonished that from milk such nice foods can be prepared. The blood of the cow is very nutritious, but civilized men utilize it in the form of milk. Milk is nothing but cow's blood transformed. You can make milk into so many things – yogurt, curd, ghee (clarified butter), and so on – and by combining these milk products with grains, fruits, and vegetables, you can make hundreds of preparations. This is civilized life – not directly killing an animal and eating its flesh.
We used to think of cow's milk as a nearly perfect food. However, over the past several years, researchers have found new information that has caused many of us to change our opinion. This has provoked a lot of understandable controversy, but I have come to believe that cow's milk is not necessary for children. First, it turns out that the fat in cow's milk is not the kind of fat ("essential fatty acids") needed for brain development. Instead, milk fat is too rich in the saturated fats that promote artery blockages. Also, cow's milk can make it harder for a child to stay in iron balance. Milk is extremely low in iron and slows down iron absorption. It can also cause subtle blood loss in the digestive tract that causes the child to lose iron. … Some children have sensitivities to milk proteins, which show up as ear problems, respiratory problems, or skin conditions. Milk also has traces of antibiotics, estrogens, and other things a child does not need. There is, of course, nothing wrong with human breast milk — it is perfect for infants. For older children, there are many good soy and rice milk products and even nondairy "ice creams" that are well worth trying. If you are using cow's milk in your family, I would encourage you to give these alternatives a try.
Benjamin Spock and Steven J. Parker, Dr. Spock's Baby and Child Care, 7th edition (New York: Pocket Books, 1998), p. 346