Round hay bales?

I'm curious...lots of people on here seem to say they feed round bales to their horses.
I've always fed from square bales so I don't know much about round bales.
What I've heard in the past and always believed was that you shouldn't feed round bales to horses.
I was told since they are so large and have to sit out for more than a day to be consumed, that the center of the bale will mold and cause horses to colic.
Is this a myth? Or perhaps it is OK to feed them in areas of the country where it is dry? I live in the Pacific Northwest where the ground is damp and it rains frequently.
Around here it is normal to feed round bales to cattle only and I don't actually know anyone who feeds round bales.

I feed round bales and in the 7 years weve had 5 horses and I've NEVER had a horse colic. We keep our bales in a barn until we use then and the middle gets eaten first. I don't think the bale would be out LONG enough for it to mold honestly because my horses eat them up pretty quickly.

The barn where I board offers round bales, which I LOVE because she has 24/7 access to hay. I'm not sure if leaving a bale out in rainy weather will make any part of it mold...ours is covered with a heavy duty plastic bale house so it stays dry. I periodically check to see how it's doing, and the hay always looks and smells great

We don't feed the round bales, but we do feed big square bales. However, we have enough horses that they only last a few days anyway. The thing about them having constant access is that if there is a portion of the bale that they don't like the smell or taste of (whether it's because it is a lesser quality, weedy, or moldy), they will generally eat around it and not actually eat any of that. By the time they have finished the rest of the bale, that part of it will be spread out and trampled into the ground. So long as you don't take enough time between when they run out and when you put out another, they won't even try to eat the crappy portions. At least mine don't.

When we fead hay we buy round bales and keep them inside and just put some outside as the mojority of my ponies are shetland ponies so don't get fed unless it snows but they still insist on being over wieght grrrr. But since we got molly we wou ld go through one in about a week but them we have 6 sheep that gets some.
How ever some hay isn't the right quality for horses it depends on the field the hay was made out of and how dusty it is ect, ect, ect ...

So if you wanted to just feed part of the bale, is that difficult? Is it made up of flakes at all?

It's usually rolled. There may be a trick to getting the hay off easily but I don't know what it is.
It's impossible to have an individual feeding program with round bales & 24/7 access. I like an alfalfa grass mix & I've never seen that in round bales, there may be though but then you'd have real weight problems.
I feed every 6 hours around the clock so round bales would be easier but they are not for me.

It's nearly impossible to feed just a little bit at a time, you have to cut the twine/plastic off and then wrestle with the pitchfork to get any loose at all. It's a huge pain in the ass just picking enough off for one horse's one meal. Plus, you end up with a bigger mess in the barn or wherever you keep it. IMHO, completely not even worth trying. When it comes to round bales, pretty much the only option is all at once.

Agree with smrobs. It's possible to peel a round bale but it's a big mess. We feed grass hay in large 800 pound round bales, 4 horses at a time. (Custom baled for us so because our tractor can't hoist the 1500 pound round bales.) They last about 7-10 days, depending on the cutting. The horses are also on pasture and seem to prefer grazing on the stockpiled grass, so they don't clean up the bales as fast as they would if they were drylotted. Last year we had grass/alfalfa mix and it was what we used during the worst of the winter; otherwise they get fed grass hay baled off our pasture. Not the very best quality mixed grass hay so they have 24/7 access but like smrobs says, they pick out the parts they don't want.

Gottatrot, if you have a medium sized tractor with hay forks, you might consider looking around for large square bales of hay. What I get is approximately 3x3x6 and 800 lbs. They are easy to flake off and it's much easier to take off one or two flakes of that rather than half a bale of small bales.