Is the date on the bottom of your feed bags the date of manufacture or the best if used by date? How long is the feed good for, after the printed date? I ask because, in February, I bought a bag of Flock Raiser and my chickens started showing signs of illness and feed consumption dropped and stopped within three weeks. I looked at the feed date and it was from November. I got a refund and got a new bag dated January. The chickens are chowing on this bag and their poop is returning to normal! Who is to be held responsible for the sale of out dated feed? Thank You in advance for clarifying this issue!