I have two African Grey parrots and, if memory serves me, the 25lb bag lasts approximately 4-5 months and the expiration date on this bag is 6/16, so I know I’ll use it well within the date. I value your opinion and look forward to heeding whatever advice you provide.
You can help keep it fresher and in best shape in the freezer in s double wrap. Say a zip lock bag sealed, air sucked out (straw works well) then put in another zip lock or a plastic sealed container. You can leave it in the big bag and deep freeze it, but if you have to open it up and dip into it often, you will suffer freezer burn and moisture getting in.