Sorry if this is an old one, but I hadn't heard it.
A farmer goes out and buys a new, young rooster. As soon as he brings him home, the young rooster rushes and has his way with all 150 of the farmers hens. The farmer is impressed.
At lunchtime, the young rooster again takes all 150 hens. The farmer is not just impressed anymore, he is worried. Next morning, not only is the rooster mounting the hens but he goes after the turkeys, ducks, even the cow.
Later the farmer looks out into the barnyard and finds the rooster stretched out, limp as a rag, his eyes closed, dead, and vultures circling overhead.
The farmer runs out, looks down at the young roosters limp body and says: "You deserved it, you horny jerk!"
And the young rooster opens one eye, points up at the vultures with his wing, and says, Shhhh!, theyre about to land."