i use those trash cans for all my feeds (horse, goat, cow, chicken) and i never leave the bag in. any moisture on your bag from storage or the trip home can spoil your feed. also, by dumping it into the can, i can monitor the quality of the grain from top to bottom while it pours in. if there are any problems (mold, moisture, insects, dry spots) in the center or bottom of the bag, i know immediately instead of when the grain is almost gone and my animals are sick. of course, you should never put new grain on top of old grain. if you have new grain and you're not quite out of the old, just dump the older stuff into a 5 gal. bucket. pour the new stuff in (watching and sniffing as you pour, not zoning out), then put the older grain on top so it gets used first.
i've seen way too many horses get sick and almost die from bad feed to mess around with the quality of my grains.
i've seen way too many horses get sick and almost die from bad feed to mess around with the quality of my grains.