I've had bears try to break into the coop in the middle of the day to get to chicken feed. No way would I chance it. I know someone who lost a whole flock of Silkies to a bear that wanted the feed left in the coop.
Yowza!!!

I'm well acquainted with bears having spent a fair bit of time backpacking in the back country; only had a face-to-face encounter once. Not something I'd care to repeat! Once a bear gets a taste for something there's almost no stopping them.
There have been no tales/reports of chicken feed loving bears around here, thankfully. If there were reports there's no chance I'd leave feed in the coop either! But I can't imagine actually having one actively trying to break in!

What ever did you do?