I use the deer forage seed bought from tractor supply. That way I know it's all safe for animals, if deer can eat it chickens can too I figure. I grow it in plant troughs though and feed it as 3-5 inch seedlings. A cheaper alternative is oats. I paid $15 for a 50lb bag and although it takes a while to sprout, it makes a nice tall grass. They will eat it, but not decimate it like they do the deer plot seed plants.