Cofra. They are UGLY and expen$ive. However, they are built to stand up to farm work. Mine endured a couple of hard years in a dairy barn and now live in my car for cold, mud, etc. They scrub up like new. More comfortable than Dunlops imo. 5 billion x more comfortable than regular rubber boots. Reasonably light weight.
Downside - the aggressive treads will pick stuff up so they need to be banged off if you walk in something gross and then want to walk down a freshly swept aisle. The treads let go of the gross stuff pretty well with a couple of heel bangs. But if you forget you will be sweeping up a few mud or poo or bedding “kibbles” where you took your first few steps.