Having spent my entire life around cows I can say there's a great deal of evidence that cows are quite intelligent. Most of the time when people say they're dumb it's because they're hindering a human from forcing them to do something. Why should a cow "know" to go one way or the other or to not stop in a chute, or to not back up...these are just human constraints. We know what we WANT the cow to do and if they don't do that they're dumb. Sure I've seen cows do dumb things. If I was an outside observer looking at the severity and frequency that humans do dumb things I would come to the same conclusion, they're dumb.

I have Cows and Pigs, raised for show and meat. I would not call either animal "intelligent". I would call them stupid determined. They have all the time in the world to push, pull, grab and generally implement mayhem.