Buying organic milk

I have recently switched to organic milk . I noticed that walmart carries great value organic milk and horizon brand.

The lady at my health food store said that horizon still gives their cows shots to make them produce milk. And that there are law suits involved with them over this, false advertising and all.

I'd like to know , where can I find on the internet that would tell me such a thing. I don't want to buy organic milk and be lied to whether or not it has or hasn't got additives of any kind to the milk or cow.

What about great value brand? why wouldn't that brand do the same thing as horizon brand.

KNow what I mean. If i'm buying organic and paying the high price, I darn well want it to be ORGANIC.