There is a linear relationship between the number of horses you own and the volume of manure you are required to manage. The most common complaint I hear from lifetime horse people is that they are sick to death of shoveling shit. On the other hand, every horse lover loves horse poo because its presence means that all is well in the digestive world. Things go wrong very quickly when animals that go 10+ times daily stop going.
I honestly enjoy mucking out our paddock, but I am alarmed by how quickly it refills with two horses in there. When Tonka was solo I was cleaning it every 3-4 days (it measures about 165 X 50 feet) with 1 day's product reliably filling half a wheelbarrow (2.5 cubic feet). The addition of Raven means that I need to muck out at least every other day to stay on top of things. In my ideal world I could do it every day, but my professional world does like me to show my face at the office now and then.