Feeding Whey

I just put mine out plain in a bowl. I don't get much, maybe a quart for almost 20 birds that are laying or pol, so I'm not worried about calcium. Then again, I don't worry about it anyway lol. They drink it right up. I'm not sure how much would be too much, but as a rule birds aren't like us humans, they don't overeat. It might eventually get nasty if there's too much for them to eat in several days, but a day or two's worth shouldn't be a problem.

I am new to chickens but I had some whey left from yogurt the other day and mixed in some layer pellets and they gobbled it right up!  I am glad to find a use for the whey-I know it's healthy but I can't get past the smell to bake with it!

This is great info since I also make yogurt with raw (-ish, since I heat it for the yogurt) milk.  Granted, the girls may have to fight me for the whey since I actually really like the stuff, but...  :D

Whey is full of protein which is great for chickens, but depending on your method of production it can also have quite a bit of lactose. Birds are not able to process lactose the way mammals are, and while surely some lactose won't hurt your chickens, it's probably not a good idea to get them too much, too often. Some won't hurt them, realistically! Chickens have been getting into milk for centuries, though arguably (traditional) raw milk is different than pasteurized. 

I often have whey while making kefir, and in the process of making kefir most of the lactose is consumed by the kefir flora, so I feel comfortable giving my chickens a whey snack once a week or so. I mix it with their leftover food 'powder' and they love it. Do whatever you are comfortable with!