I'm so glad this has been useful to you!
I don't ferment grains for the chickens. I have found it hard to make sure I'm fermenting the right thing usually with grains and generally, I like the idea of GROWING seeds a little in order to create more enzymatic activity (aka life force). I've tasted too many fermented grain concoctions meant for even human consumption that were "off". Fermenting regular chicken feed seems insane to me. There are almost always chemicalized vitamin mixtures in there and they are often treated as a whole with high heat or are at least ground up making the fats break down badly and who knows what kinds of bacteria would be growing already on such a product. Yikes! I won't even ferment organic whole grains let alone perhaps old, ground up, highly heated, additive ridden chicken feed! I wouldn't ferment anything but raw natural foods myself.
I keep the ferments for the chickens to the ferments that I myself would eat. My chickens love fermented dairy and even kombucha scobies - which is a very nice use for the extras. They eat lots of fermented things in the yard as well. Fruits that naturally are fermenting and things that lie around fermenting and I feed them every second day what is called "high meat". I open a 2 pound or so package of ground up whole raw grass-fed cow and give them half and the other half I mix periodically to keep all of it exposed to oxygen so that the good bacteria in/on the meat can grow and provide excellent gut bacteria for the chickens and feed that on the second day.
Whey is the by-product of making cheese and can be a by-product of making yogurt as well. The softer the cheese the less whey has been removed. I haven't worked with goat milk but of course you can get whey out of raw goat milk! I would suggest picking what kind of cheese you might want to try making from your goat milk and using the leftover whey for the chickens but if you are going to use the milk only for the whey - I would suggest not going through the trouble of siphoning off all the whey and just fermenting the milk in the easiest way for you and then feeding it whole to your chickens. That way they will get some good dairy bacteria, carbs and other good stuff from the whole fermented milk as well. Chickens tend not to be very picky about the kind of cheese they eat. lol. If it's fermented dairy that isn't too sour you'd have strange chickens indeed that wouldn't gobble it up. Goat milk tends to be naturally homogenized so the chickens would also get a nice good source of fat as well with the whole milk being used.
It's a bit of a study to learn to make these things but once you get it down - you got it! There are lots of great sources on-line on how to make cheese. It's really a lot of fun and is quite empowering. Some of the hard cheeses are not so easy because they need exactly the right temps and only particular strains of bacteria - but there are some simple softer and younger cheeses you can try. With goat there is chevre and feta for instance. YUM! I'm jealous actually. I'm thinking of getting a couple of tiny goats for my little suburban yard one day the animals and the milk are so wonderful to have. What I really want is my own fermented butter again. Oh - that was heaven!
You are getting into chickens and into raw fermented dairy. You are going to have a grand time! It was like a whole new world opening up learning about those two things for us.
Well I plan on sprouting/growing fodder for them, since the area they will be in doesn't really grow grass. Out here in the desert grass needs loads of water to survive and I don't think the chickens would appreciate being watered constantly, haha. I'll probably be sprouting mostly wheat and barley grass for them, and experiment with what other sprouting grains I can mix in for them. Fermenting sounds good to me because it helps break down the seeds to be more digestible, and it provides so many good bacteria! I do want to avoid pre-made feed like the plague. Dog kibble grosses me out and I think I'd have a nervous breakdown feeding it to my dogs, so I don't want to feed "kibble" to my chickens either. Processed, dry, hard little nuggets just do not seem like food to me!
I didn't think about just fermenting the milk instead of making cheese. Would that contain as much methionine as the whey from cheese? Could I just mix it in with their feed to make sure they drink it? I do like the idea of just fermenting and feeding the whole milk, since goat milk has so many great nutrients. I don't actually have goats, but I know of a few good sources I can get raw milk from pasture fed, well loved goats for relatively cheap.

I don't really have access to free-range beef or lamb, the cost is astronomical around here! I want to raise meat rabbits as well, enough for it to be a staple for my dogs and us. I assume the chickens could have rabbit too? Rabbits will live in large pens instead of cages and eat a natural, pellet free diet as well.
