How much food does my dog need?
The amount you feed your pet can vary, depending greatly upon the breed, activity level, metabolism and preferences.
Food remains fresh for 6-8 weeks after opening the bag and exposing it to oxygen.
Nutrients degrade over time, decreasing pal
http://www.whole-dog-journal.com/issues/15_12/features/Fats-Chance_20658-1.html
Make sure you select the right amount for your dog(s).