If I am going to add horse manure that has a lot of wood shavings to my compost should I do anything special to make sure everything decomposes well?
I use horse manure with a lot of wood bedding in my compost. (That's understating it: my compost is mostly horse manure with wood bedding...) I've found that:
- making sure it stays moist;
- adding whatever nitrogen sources are available (kitchen scraps, lawn clippings, chicken manure, etc); and
- turning it occasionally
gives me great compost after 6-12 months. If it's dry when you turn it, add water. If these are your horses, you can help it stay moist by dumping the leftover water from the buckets onto the pile.
During the summer (lawn mowing season) I find that layering 1" of lawn clippings with 3" of manure+bedding gets hot fast. With a good sized pile, and turning every couple of weeks, you can have nice finished compost by the end of the summer.
Also, keep in mind that the bedding can absorb a lot of urine, which is very high in nitrogen. So if the bedding is well soaked, you may not need to add tons of extra nitrogen to get it to break down.