I feed rounds to 3 horses who live out 24/7 with a shed. Sometimes I let them have free access, sometimes I limit it. A 650# 4x4 lasts 10 days with 24 hour access, limited access will stretch it to 15+ days.
My climate is very wet year round. I could never let hay sit on the ground.
I have two run-ins, one I use for hay storage, the other is protection for the horses. I can store 10 4x4 rounds inside the hay storage side. I made a removable chest-high half wall so the horses can hang their heads over the wall and eat free choice and the bales are completely protected. I leave the netting on the bale and peel it back each day, and the bale stays up on a pallet on rubber mats. That is by far the least time-consuming method for me, but still daily work as I have to clean up any chaff thats spilled around the bale out of their reach, or they dragged over the wall. Any chaff sitting inside the barn will mold quickly, any outside the barn will get wet and turn into mud.
I primarily open up bales, unwind them and stuff them into big hay bags however. I usually bag up about 6 days worth at a time, it takes a few hours. Its much more labor-intensive, but there’s very little waste and I have complete control over consumption for my easy-keeping herd. It also allows me to feed several varieties of hay per day, which is what I prefer.
Currently, the boys have access to a mature timothy orchard bale so they can nibble 24/7 but won’t gorge, and they’re supplemented with bagged 2nd cut orchard, alfalfa, and a pasture mix that is primarily crabgrass.
I’ll also open up bales if I think the hay was baled on the damp side and might caramelize (or worse, mold) if left to sit. I can bag up almost half the bale which allows the inner core to cool down, dry out and cure up properly.
A lot of things can be hiding in a big bale, even good looking ones can be molded inside due to a wet lap from a shady field edge or a chunk of damp earth, etc., things the farmer just can’t always know. I inspect the hay my horses are eating daily. My climate is just too wet to trust on big bales.