Cows

City woman, who's visiting a western dude ranch, talking to a cowboy:

She: "Hey! Look at that bunch of cows!"

He: "Not bunch, herd."

She: "Heard of what?"

He: "Herd of cows."

She: "Well, of course I've heard of cows!"

He: "No. A cow herd!"

She: "Why should I care what a cow heard? I have got no secrets from a cow!"