I have a barred rock rooster, neary a year old, that a couple of weeks ago started walking around with his head/neck twisted to one side. He does it first thing in the morning when I go out to the chickenhouse to feed them, then after a little bit, he'll straighten up and look like all the others. Any idea what's causing this? Is it something to be concerned about? He does appear to have a slight tilt off and on throughout the day, but generally his head/neck seem to be fine once he "warms up".