A blonde city girl marries a Texas rancher.

One morning, on his way out to the fields, the rancher says to
her,

'The insemination man is coming over to impregnate one of our
cows today.

I drove a nail into the 2 by 4 just above the cow's stall in the
barn.

You show him where the cow is when he gets here, OK?'
The rancher leaves for the fields.

After a while, the artificial insemination man arrives and
knocks on the front door.

The wife takes him down to the barn.

They walk along the row of cows and when she sees the nail, she
tells him,

'This is the one, right here.'

The man, assuming he is dealing with an airhead blonde, asks,

'Tell me, lady,'cause I'm dying to know;

how would YOU know this is the cow to be bred?'

'That's simple. By the nail over its stall,' she explains very
confidently.

Laughing rudely at her, the man says, 'And what, pray tell, is
the nail for?'
She turns to walk away and says sweetly over her shoulder.

'I guess it's to hang your pants on.'

(It's nice to see a blonde winning once in awhile)