I am so sorry you are having to deal with this. Yes, people suck! I'm not positive on this, but I think that your goats will not eat the spray-painted part of the hay. I know the first thing my girls do is smell their hay, and if it doesn't smell right they won't eat it. I can tell you that my girls won't eat weeds/grass/browse that has been sprayed with herbicide until about 12 to 24 hours after spraying. I would think spray paint would be the same way but, again, I'm not positive about that.