Actually, the fodder can grow long and the danger here is that it very well may roll up into a ball in their crop and cause them to become crop bound.
What I do with my sprouts that are a few days older is cut the blades of "grass" into one inch lengths (roughly). If my fodder has made it to 4 or 5 inches, I mow it with the scissors, then I'll untangle the mass of roots/sprouts and mix all that into their feed for the day. They love it and I don't worry about them getting crop bound.