First, I will say that different methods are used by different dairy farmers to disinfect the teats of the cows both before milking & after milking. This is done not so much for our safety as for the cows. If not properly disinfected, the cows can get mastitis which in a nutshell is an infection of the teat & can lead to big problems for the poor cow. The most common 2 methods are dipping & spraying. Dipping is where the teat is dipped in a cup of iodine solution & then that is supposed to be rinsed off & dried. Spraying is where the teat is sprayed with an iodine solution. Most commercial dairy producers use one of these 2 methods. SOME don't but those are the minority. Do not think that if you buy "organic" milk that iodine is not used. I called several which stated "organic" on the milk & they said they use the iodine solutions.
I did find one dairy farm near me (I'm LUCKY!!!!!!) who does not use the iodine pre milking (they use a different cleaning method) but they use an iodine wash post milking. They grow their own feed so there is not iodine in the food the cows eat. I will have to do a challenge on their milk & cheese products but the iodine content in their milk HAS to be much lower than anything I can buy in the grocery stores here.
Here are some links:
And here's an article describing the disinfection processes as well as graphics showing how it's done.
Edited to add the last link.
Edited by squirmingitch, 13 February 2012 - 01:48 PM.