Went out this morning to find one of my chickens dead. My husband opened her up and found a large clot in and around her liver. Everything else looked fine. Fair amount of fat around her bottom, no egg bound. I feed my four ladies one sandwich bag full of spent grains from the local breweries, occasionally a 1/4 cup of chicken Crack and they have access to layer feed that they rarely eat (40# bag lasts over 2 months) plus some leftover veggie scraps. Am I over feeding?