Painting or stain a wood livestock fence--is it worth it?

Hi All,

We've got a small hobby farm with 6 acres of pasture. We're planning on repairing the fence so we can get some livestock back on the pasture.

You can see pictures of our property in the first post here:
Here's my property--am I asking too much of a SCUT? - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information

And quite a few more here (taken before we purchased the property):

One thing I'm thinking about is painting the fence. We would not do this purely for cosmetic reasons--it would need to prolong the useful life of the fence by preventing decay and/or dry-rot. As I read through descriptions of various paints and stains, I'm uncertain if there are products that really do that, or if it's really for cosmetic reasons that you would paint your fence.

The most affordable fence paint I've been able to find is the stuff Southern States and Tractor Supply Co carry, which is Lexington's stuff: Southern States Online Store - Lexington

I haven't been able to find many reviews of this stuff, but the few I have found have been positive.

We would have around 3400 feet of fencing to paint, and I'm estimating about 2300 feet of that would be on old, weathered (but relatively clean) fence. If we're going to have to take a belt sander to all those old boards to grind it back down to blond wood, then I think that's a dealbreaker... I just don't know when I'll have the time for that! I'm hoping there is some paint, stain, or sealant that can just be sprayed on... but maybe I'm hoping for the impossible?

-Josh

it's mainly up to you, any type of acrylic paint will do the job I guess, but you should firs spray the fence with some wood sealant spray.