alfalfa i get the pellets meant for chickens, or in a real pinch, the cubes for the goats.
Be slightly careful the collard greens, as they are extremally high in calcium. While good for the cham, its poison to bugs. So too much and you may get a die off over time. But if you have "the chosen ones" and feed them your mix a day or two before their sacrifice, it would be wonderful.
Also it starts to rot very quickly so replace every day or two. Alot of us just make batch and turn them into icecubes, and put one cube in per day or every other day. Gee i wonder what happened to the other 90% of the papaya