Nasco is probably my favorite source for farm supplies. You can get anything from egg cartons to complete AI kits. The problem with shopping with Nasco is that their website is a nightmare. You have to know where things are to find them and their search box spits out random results. So, I can’t just give you a link to their website and say, “Go get ’em.”
Here’s a link to important pages buried in the Nasco website:
FYI: Nasco is the only place I’ve been able to find an attractive leather halter for dairy cows.