Alfalfa sprouts , grass, red peppers and carrots seem to do the trick too.
Yes, you can sprout many different seeds. I use barley because it the least expensive and best sprouting seeds where I live. I have also sprouted oats and wheat, but with less productivity and a higher cost for those seeds. So, I just use barley.
I also feed my chickens all our kitchen scraps and leftovers. It's not a lot per day, but it's a nice little variety in the diet for the chickens.