Manure from horse people is available. It's the gas that makes it
expensive. I could spend $200 in gas on just a few trips. Anytime that
I can include manure in a trip or get a trailerful, I do.
I once had a deal with a guy who had a horse boarding operation. I
left my friend's horse trailer parked there, the horse guy filled it
with stall cleanings--he used a wheelbarrow and ramp--and called me
when it was full. I would drive over, pull it home, unload it and take
it back, working in a shopping trip on the way home.