p.s. I had to email my dad asking him what exactly was in the milk because i couldn't remember. The paragraph he sent to me is so great, i'm putting the whole thing in.
Usually it was a piece of straw or a flake of some kind that fell into the milk while it was being moved from the cow to the milk can. Sometimes it was more than that (manure) but that was very rare. Eventually they changed how cows were milked and the milkers sent the milk directly to a big vat that was cooled and there was less chance of something getting in it. It is also true that the cream might be twelve or fifteen inches thick and was so thick it would turn into whipped cream with just a few turns of the mixer. Farm life was interesting.
Hahaaa.. Mmmmm, manure milk. That last line makes me laugh.