Hello, hello! Found my feed bins meant food was left at the bottom and slowly rotted. The plastic bins we previously had never lasted as rats kept attacking to get to the rotting feed. Found a local (uk) metal engineering company that had the same problem with their farm at home and had made the perfect solution to store feed!
Bit pricey but have had mine a couple years now and havent had an issue with rust, vermin or stale food. Would recommend to any with similar problems. They have a new website thought i'd pass it on.
My-Fifo
Horse feeding bins! 
