Try making your own yoghurt with goat milk or sheep milk if you can get it. That way you know the good guys will be strong and plentiful.
I got a simple, cheap maker from http://www.easiyo.com. I wouldn't use thier starters and packet mixes. I just use organic milk and a couple of spoons of yoghurt to start it off.
I'm sure it would work with goats milk. Does anyone make their own with goat or sheeps milk?