A cattle rancher decides his bull is getting a little to old to take care of all of his "duties" with the herd, so he goes to the local livestock auction and buys a new, buff, young bull. He brings him home and turns him loose in the pasture with the cows. While standing on a hill looking at the herd, the old bull starts snorting and pawing at the ground with his hoof. The rancher looks at him and says, "Oh, calm down. You're getting too old to take care of all those cows any more." The bull looks up and says, "Yeah, but I can at least go down and show him I'm not a heifer!!!"