As mentioned in another post, I moved my Cornish Xs to pasture a couple days ago. The pen allows for 1.5 sq. ft./bird. The poop build-up is more than I thought it would be. Do I need to worry about this? So far I've moved the pen once per day. I'll aim to move it twice per day - should help. However, they seem to be overly concentrating (pooping) in the covered part of the pen. Thoughts?