A man and his animals

A man decides to start a farm. So he walks into town to buy some animals. At the farmers' market he first asks for a rooster.
"We don't call them roosters here," the clerk says snootily. "We call 'em cocks."
So the man buys one cock, then points at another animal and asks: "What do you call that?"
The clerk replies: "That's a pullet."
The man agrees to buy one.
Finally, he asks for a donkey.
The clerk replies: "We don't call them donkeys, we call 'em asses, but we only have one left and he's very temperamental."
"What's wrong with it," asks the man, who is determined that he must have a donkey.
"Once in a while it will stop walking and it won't budge unless you scratch it behind the ears," says the clerk.
The man decides to buy it anyway, and pays for all the animals before starting his walk home.
On the way, the donkey suddenly stops and doesn't move.
But the man has his arms full with the rooster and pullet, so has to stop a woman who is passing by to ask for help.
"Pardon me," he asks politely, "would you mind holding my cock and pullet, while I scratch my ass?"