We have St Patrick's Day parades here where cabbages are thrown, the whole head. They keep well and my hens like when I hang them from a rope off the ground so they have to play with the cabbage to get a good bite. Also love any thing red in color. We also do the old farm family thing, anything that may not be eatable for the family ( the important word is may, won't feedsomething I know is bad), the exception is milk, let it solidify and feed the curds. Any scrapes from dinner prep or leftover on a plate goes in the hen container for the next day. I have a neighbor who does the same for me. She is the first to get extra eggs. Also allow them in the kitchen garden after harvest and removing tomato plants, they free range the backyard everyday and occasionally front yard with supervision. Lots of protein, like lizards, frogs, worms, etc. We crush up egg shells real fine, and feed for calcium. Sure cuts down on how much feed we have to buy.
) I've tried cabbage, and they aren't too fond of it... but I'm sure if i tied it up with some string, theyd find it more fun and maybe enjoy it a little more 
