Our ASF's do like a bit of greens to nibble on occasionally. I don't use cabbage or head lettuce though do to what Sean said about high water content and basically it just goes through them like grain through a goose. I usually get stuff like collard, mustard or turnip greens cheap as dirt at a local small grocery store here. They love it but I only give it as a treat type thing. Their standard dry food here is a mix of small cat kibble, mixed grains and nuts (good quality wild bird food mix) and small type no sugar dry cereals.