I use peat moss and I’m extremely happy with it.
3 horses live out 24/7 with a large run in. All 3 go indoors to escape the elements/flies several times a day, and sometimes lay down for a snooze. Constant in/out traffic all day. All three are very good water drinkers and routinely make lakes. The newest addition to the herd prefers to potty indoors … sigh.
Peat moss is inexpensive where I am, about $16 for 3cu ft bale. 2 bales is a 6 month supply for me.
Run in is fully matted. I sweep the mats completely clean and if needed, let it dry a day. I spread both bales of peat moss down in the back corner of the run in, roughly a 12x8 area, appx 5" thick layer that I taper down at the edges.
Peat moss looks and smells like dirt and is exceedingly dusty if allowed to dry. After spreading, I thoroughly water – think 3 or 4 “passing rain shower” applications over the course of 2 hours or so. After fully wetted, I take clean, DRY, uneaten hay (I collect what is left over from the day previous and keep it for this purpose, and for covering compost piles to cut down on fly activity), and spread it over the top of the peat moss bed.
The peat moss is spongy and soft like a mattress. The hay on top knits together with hoof activity and creates a layer - rather like a quilt - that doesn’t shift, track or move much at all, and keeps dust to a minimum. The horses don’t bother with the hay as it’s something they already aren’t interested in. They can lay on it and not have their coats come in contact with the peat.
When they pee, the pee filters down through the hay layer and is absorbed by the peat. The hay layer dries quickly. The peat neutralizes any smell. The entire shed is clean and sanitary smelling and dry to the touch/hoof/coat.
The peat is so insanely absorbent, 3 horses can use the stall a couple times a day for weeks on end before there is any sign of wetness. When there is a sign of wetness, I peel back the hay layer, remove the wet spot with a shovel, and then rake in some fresh peat from the edges to refill the hole.
Then, the soiled peat is tossed directly onto a poor section of the paddock for a near-instant soil improvement.
I used sawdust for years, but battled dust almost daily, watched it get tracked around and create mud where none was previously and went through about 3 bales a week in removing wet spots. I tried straw, but one knucklehead decided to eat it. I tried pelleted bedding but that too became dusty from the in/out of mud caked hooves and also got tracked around.
I even tried shavings over peat, but the shavings got churned in and it became a dusty disaster. A layer of a long fibrous material like hay or straw knits. Just whatever you do, make a mattress with it and then leave it alone to do its job. Do not attempt to try to “muck” it daily with a rake or tend to it above occasional watering. Trying to treat peat like shavings or pellets will bring you to tears.
The ONLY drawback I have is that it’s a pain to pick manure piles from the hay layer, balls want to shift down below the hay, or the fork wants to drag the entire quilt up. This wasn’t much of an issue until the recent addition who likes to leave 4 or 5 piles for me every day.
But for pee, peat can’t be beat. I can’t imagine ever using anything else.