I just have a small flock of bantams so 50 lbs of feed will last awhile and they're on Flock Raiser. TSC just started selling Purina feeds and are having a special on them, $2-3 off their regular price. I'd gotten my Flock Raiser from the local feed/farm/garden store a few weeks ago. TSC's regular price is $1.00 cheaper than the feed store's price. They seem to be doing well on it and I'd planned on keeping them on it. The TSC price is a good deal, but I just didn't know if there was some sort of expiration date for bagged feed. I've already thrown away the bag the feed came in since I keep it in a plastic bin inside the house.