Cock

A farmer buys a young cock. As soon as it comes home, it rushes and screws all the 150 hens. The farmer is impressed.

At lunch, the cock again screws all 150 hens. The farmer gets a bit concerned. 

Next day, he finds the cock screwing the ducks and the geese. 

Later, the farmer finds the cock pale, half-dead and vultures circling overhead. 

The farmer says: "You deserved it, you horny bastard!" 

The cock opens one eye, points up and says: "Ssshhh. They're about to land!!.."