This was actally an Abbott and Costello routine

Two west country yokels were on the train heading homewards through Somerset, England when one of them noticed some cows.

'What a lovely bunch of cows.' he remarked.
'Not a bunch, herd,' his mate replied.

'Heard of what?' he asked.
'Herd of cows.' his mate answered

'Of course I've heard of cows.'

'No, a cow herd.'

'What do I care what a cow heard. I have no secrets to keep from a cow.'

dan - like this one !

It's funny because Abbott and Costello were both prominent figures in the Australian Liberal party.