When I moved to this farm I had never seen the type of latch that I found here. It's called a chain hook, and it's pretty much just that. It has a small link on one end that you can attach to your gate, and a hook on the other side that has a catch in it.
|chain hook setup|
|the chain hook itself|
The biggest reason that I like this latch is that it can be latched and unlatched with one hand, and pretty quickly. Once latched, it's impossible for the animal to unlatch no matter how much it's wiggled. So a cow that is messing with this latch will never get out. Pigs usually don't get high enough to bother the latch, but it's nice to know that if they did they'd be defeated too.
These are about $6, and i purchased them online, from kencove, but I am mixed about kencove as a merchant. I ordered 10 of them, and it took about 6 weeks for them to get to me. That's a very long time. I ordered another 20 of them, and if it takes 4 to 6 weeks to get them, I don' think that I'll order from them again.
I'm going to switch most of the gates on my farm to this latch.