Now, I realize that not everyone knows everything. That's the beauty of the internets, and a major reason my herbal teachers encouraged me to write in the first place- we all have something to say, and it will be new to someone! I recently read an article called, in fact, "Actually, Everyone *Doesn't* Know That," a primer on why so many people hate that Monsanto thing. While I have mixed feelings about the actual writing, the heart of the piece was great, and was very welcoming to people looking for answers.
So here's why that conversation dumbfounded me, for anyone who may not see a problem with it: "grass-fed" means "as compared to penned-up and stuffed with corn and other grains", not "the groomed stuff of gated suburban lawns." Cows are grazers, and really "chew their cud"- they re-chew plant parts that are hard to digest, and their 4-part stomach eventually breaks it all down.
In comparison, no matter how much chewing we did, we'd never get as much nutrition as cows do from what they eat. And what they eat influences how their milk tastes, as well as what's actually in the milk- vitamins like A and D, conjugated linoleic acids (CLAs), or growth hormones, trans fats, or other toxins . Common cattle feed has much, much higher exposures to pesticides, contains antibiotics and other chemicals, and often even contains slaughterhouse wastes and euthanized pets (sources below.) In addition, imagine what you'd be like if you ate nothing but carbs all day, every day- these are not healthy animals.
Grass-fed cows, by their very nature, are raised on pasture. A certain amount of land is needed per cow, and this leads in part to the higher cost of their milk. Now, exactly how cows are treated depends on the farmer. Some refuse any and all antibiotics, some will use them for sick animals but not sell their milk during a quarantine period. Some supplement with corn or hay. And of course, in temperate climates like the Northeast, there simply is no grass growing in the dead of winter, so feed must be procured.
The topic of raw vs pasteurized or even ultrapasteurized milk (which some people consider a 'processed food' like common junk food) is a whole 'nother topic. Suffice to say, the smaller the outfit you can buy your milk from, the better off you'll usually be. Really, that's a good credo for all your food shopping. You are what you eat, after all.
Lipinski, Lori. "Milk: It Does A Body Good?", Weston A. Price Foundation, July 7 2003. http://www.westonaprice.org/making-it-practical/milk-it-does-a-body-good
Severson, Kim. "An Organic Cash Cow", New York Times, November 9 2005. http://www.nytimes.com/2005/11/09/dining/09milk.html