Farm Excursion?

[Dixie]

Mother: David, did you enjoy the farm excursion?

David: Yes it was great - we saw sheep, horses, goats, and fuckers.

Mother: Errr, fine, fine. I know what the sheep and the rest are, but what is a fucker?

David: Oh, they're the animals that give us milk.

Mother: But who said they were called, er, fuckers?

David: That was our teacher. Well actually she called them "effers", but we all knew what she meant.