buffalo

[potetjp]

Waruno,
The root *bau "cow" - from which *bu is probably derived - is found in a
large number of Philippine languages. In Fe ALDAVE-YAP (1977: _A comparative
study of Philippine lexicons_. Manila: Institute of National Language) 48
languages have _kalabáw_ or something similar, 2 _...-biw_, and 2  _...-bo_.
24 remaining languages use terms derived from the stem _nuwáng_.
6 others use terms derived from _dang- + bulág > damulág_
Finally the last 4 use terms derived from the stem_dipóg_.
The last three stems sound native. Only _kalabáw_ and its alikes seem to be
foreign. As you rightly say, these terms are probably borrowed from
Mon-Khmer.
I suppose the root *_bau_ is the cognate of IE > Latin _bo-s_ "ox", Greek
_bo-os_ etc.
Best
Jean-Paul