carders. caching. They might also be dog hair combers, I heard you can use that as well.
In any case, I took out some of the dirt and hay and other undesirable stuff, then washed it in the washing machine with a little bit of soap. I just put it on rinse and spin cycle, so it didn't felt. It's still a little gummy, but I think it's ok, I'm letting it soak in kool aid as I speak, or write. I'm thinking of maybe using it for some needle felting experiments.
The other roving, the one which led to this discovery, did seem to felt, or at least the fibers looked a whole lot different once it was washed. It still seems to spin just fine. Now I'm fiber content.