Can you post a photo, Melissa, or better describe the damage? Does it look like the plants have been chewed, for example? Many folks have been having trouble with lubber grasshoppers these days, and young collards certainly wouldn't be immune. If that's what your problem is, there is little you can do but put a cover over your plants.
A picture would be helpful so we can see the damage. Maybe one as it lays on the ground and then a close up of the damage?