Mine eat every piece of corn they can possibly get off the cob. It is picked clean after a few minutes with them. I give them the cobs after eating most of the corn off, since there is stuff there beaks can get that my teeth can't! Then again, I always buy a few just for the chooks when buying sweetcorn for dinner.
Since I eat sweetcorn raw with nothing added (don't knock it 'til you try it!), the chooks get it raw off the cob like me.
Mine peck the cob clean! It's a great treat and with all the corn fields around it's free 'til harvested! Anyway back to the subject i've found also that what is not at first eaten usually is eaten later.