I assume there was a problem with "bou" in DL's TTS, and somebody tried to fix it with the hint "b-ou". But DL pronounces isolated letters as in the alphabet (a, be, ce ...), so now it's be-ou.
It's funny how there are subtle similarities between the Proto-Indo-European languages. In Romanian; "ox" is bou, in Irish; "cow" (a similar animal) is bó.