My son got a short paycheck last time and unbeknownst to me he bought our chickens whole kernel corn last week instead of their usual feed, because someone at the feed store told him they could eat it and it was cheaper than their regular feed or cracked corn. Will this hurt them? I am going to buy them some regular feed tomorrow but they have (sort of) been eating the whole kernel corn for a few days. I am worried that they might have a problem with impacted crop?, although they do have plenty of grit.