I really doubt they leave bags of feed in a warehouse for months, the feed will go bad. Yes it is possible that bag might have gone bad.
I have had chicken feed here bit longer than I wanted you can smell the difference opening the bag.
I have seen feed in stores 8 months past mill date. It definitely happens.
Since they changed how the date appears it is far harder for the average shopper to decipher.
I find this useful since it has a converter.
https://www.juliandate.org/