Definitely call him; or go to the store. Ask him if he has plans for after work, then say, "No? Good, I'm going to stop by at (insert time here)". give him enough time to go home and change (horsefeed stink, yuk), but not too late where he would have eaten or gone out.

You may want to add in your conversation that this whole experience is new to you; and you're just trying to figure it out as you go. I would like to see a little insecurity in women, as it shows their vulnerable as well. It's sexy, cute, and it helps with a guys ego too. As I'm sure he's a more "macho" type since he works in a feed store etc. Kinda "cowboy studliness".

Oh, and I don't think horses "stink" per se. But I'm not sure if it's a sexy smell on women.