A certain amount of chicken mash gets ground into dust during processing. These "fines" are so dusty chickens won't eat them. Here's how I make sure none of that dust goes to waste: I scoop up a days ration of mixed crumbs and fines, then dump them into a large screen-covered strainer that lives in a large-mouth funnel. A few quick shakes of the strainer and the fines go down the funnel into a large jar. I feed the mash crumbs, and save up the fines. When I have a reasonable amount, I give the hens a treat: I mix the fines with water in a rubber bowl--usually making up a batch about the size of a softball. When It's nice & wet (but not drippy) I put it out in the run on a piece of old plywood. The chickens like their porridge even better than dry mash crumbs. They don't waste any time at all chowing down on it. Feed prices are going up fast. A pound of fines is the same as a pound of perfect crumbs, feed-wise, so it's good to not have to waste it.