I bought a bag of layer feed from my local feed mill for my chickens, usually I get a bag of the prince organic pellets. They had a new guy load my feed for me it is ground really fine, I think it may be for making mash. No directions on bag though for making mash. Going to get new bag tomorrow, hate to waste this bag. Anyone got the grain/water ratio? I have never fed mash before.
Not sure how many birds you are feeding, but I pull out a 5 gal bucket (Lowes, Home Depot, doesn't matter, long as its cheap) and throw 40-5 scoops with a plastic coffee can (Folger's Black Silk, I think? Breakfast blend and French Roast are OK

) Walk around the side of the barn to the water source, open the spigot, let it pour in.
I have sturdy 1x2, about 4.5' in length I use as a paddle to stir it as it fills with water till I get a loose oatmeal consistency. Stop the water, stir another minute or two. Will thicken further - no idea why or how.
You're done.
Add a little more water to just cover, put a lid on it, forget about for 2-5 days (climate dependent) and you have fermented mash. Sometimes with a white powdery something on the top 1/16". Its harmless. Kahm, a yeast culture bloomed in the presence of oxygen. Its why airlocks are used for fermenting beer , wine, etc - vessel fills with CO2, Kahm can't form - no oxygen. If you keep your mash underwater, no kahm, because no oxygen - but I find that makes my mash more soup than oatmeal.
Others may be doing it better.