Shit, this may not apply to the dairy industry however. I found this on an organic dairy website http://www.oberweis.com/web/milk.asp:

"Organic certification requires that milk be discarded for 12 months after antibiotic use. This has the unfortunate side effect of making a sick cow such a financial burden to a farm that it must frequently be killed. When this happens, organic farmers generally milk the sick cow (and sell her milk to be bottled as organic) as she gets sicker and sicker and as the quality of her milk deteriorates. She is slaughtered once her milk approaches legal limits."

So that sucks.