The best thing about horses (in my view) is that garden plants like the manure they make. The second best thing about horses is that they make lots of it.
A lovely lady not far from me has two horses, and she has been carefully heaping up their droppings in a corner of her field, for a couple of years. It's wonderful stuff, well rotted, ideal for the garden. I have collected a few loads before, in my trailer, and arranged, this time with my Dutch gardening enthusiast friend, to visit again.
Collecting it is not without its hazards: last time my car got stuck coming out of the field, and the wife had to come and rescue me, bringing a pair of steel ramps to get me over the steep slippery bit. My Dutch friend was having none of this, leaving his car outside the field while I drove in (armed with ramps this time, just in case).
All was well. We filled my trailer and wheeled several barrow-loads each out of the field to his waiting car and trailer, and took them home. Now he wants to go industrial and hire a lorry and digger and collect the whole lot in one go. Economies of scale (and of effort) do make this attractive, but originally, I had, essentially, an inexhaustable supply that I didn't have to store, and could collect whenever I wanted. And it was free. Hmmm. Be careful what you wish for.

A trailer load for me

Some barrows for him