None-the-less, I've found that my "girls" like clabbered milk, often called buttermilk. Such a treat for them... they go WILD! Rich in Vitamin B, calcium, and probiotics, I believe it's good for them, too.
Interestingly, according to the American Poultry Advocate, Volume 23, written in 1914, "Sour milk, buttermilk, skimmed milk all have a tendency to keep poultry well and in the doing this prevents much growth of worms". Now you might not put much stock in that, but apparently, it certainly wasn't seen as harmful to chickens. Keep in mind, back in 1914, most farmers had their own raw milk source, so don't confuse this with pasteurized and homogenized milk. In order to have probiotics in the milk, it would need to be raw.
So, do you give your chickens raw milk? I'd love to hear your thoughts!