We keep our feed in a few different places... Our barns and areas are animal seperate (each type of livestock have their own areas).... For the goats and sheep we use huge plastic foot locker type of containers... these have a latch for locking the seem to prevent them from opening and free eatting... The Rabbits and Chickens have their own huge 55 gallon garbage cans for feed. The pigs have old freezers that do not work anymore to store their feed... The horse also has a foot locker type of container for her feed...
We have 'general feed' too for all the animals such as treats (sweet feed), alfalfa blocks, beat pulp, DE, oyster shells, etc. etc. that we keep in freezers, foot lockers, garbage cans.. Just depends on the feed.
All the freezers we acquired for free... others had them and were going to take to dump... we didn't need them to 'work' so asked for them... we keep on in front of the gate for the pigs, as otherwise when they get bigger, they will beable to push the door open and will end up running freely in the barn...lol
So far all things have seemed to work and no problems with rodents getting into anything... At times we had to leave in feed bags too as ran outta storage for the feed... still no problems with rodents...
We do have a gravity feed box next to the barn, but we have yet to use it in all the years we have been here... Not sure on the size...but it is big...lol