I wouldn't recommend that care sheet. Its full of lots of the old wrong info.
I've never fed hay to a CDT. Not even an adult. If I was inclined to try it, I'd cut the hay with scissors in to more manageable sized pieces and soak it to soften it up before mixing it with their greens.Do you feed hay to your CDTs? If so what is the best hay to offer, alfalfa, orchard, timothy??