I homebrew in 5 gallon batches, resulting in several gallons of mash that I've fed to our little urban flock of
chickens and which they consume with great gusto. The first time around I allowed them to share a gallon or two among the 3 of them in an afternoon and one of them became egg bound and nearly died shoftly after. Perhaps it was just conicidence (the other birds were fine), but my spouse has now restricted their diet to a few yogurt tubs of mash per day on brew days. I don't recall any difference in egg flavor.
In terms of storage- its warm, moist stuff, so it can and does, in my
experience, go moldy pretty quickly. Since I don't create a huge volume anyway, I bag it up and throw it into the fridge...not so practical for 250 gallons!
And while I'm thinking about it... I worked at a microbrewery several years ago, and we often sold (or gave away, I'm not sure) our waste mash to a farmer who raised cows or pigs or both. Heh, and I recall getting ribs at Goose Island Brewery in Chicago once because I was so smitten with their schtick about "beer fed pork"- apparently they sold their mash to a farm outside of the
city, then bought the pork from them. So, there are definitely folks doing it...
