Like birds, it has been found that cows have regional accents. On the BBC news site they have recordings. Whilst I'm quite happy to go with mooing variations, I'm not terribly convinced that the cow accent should be in any way reminiscent of the human accent, as the Five Live snippet seems to suggest.
This is also discussed on language log.
(This is a case of something which has been 'spun' from 'it is possible' to 'it is true')