A load of bull

[magicmick]

A young bull and a old bull were stood on top of a hill looking down on a herd of cows grazing in the bottom field, the young bull said "let's run down and "service" one of those cows" the old bull said " no let's walk down and "service" them all"

[starone]

Tee-hee, easy does it.

[Valmave]

If I remember correctly, that one was in the 1963 edition of the Boy's Book of Jokes.