As well as millions of other ruminants.
But then there weren't millions of paved over grazing acres then, nor were they being fed corn which irritates their stomachs and causes them to fart even more. Corn, the farming of which, btw, also depletes natural grounds and degrades them.
Now you extend that to a planetary scale (check the number of cattle in India alone), and there's a whole lotta biota being turned into flatulence.
Not saying this gives credence to the Global Farting rage, but just comparing numbers of wild bovines past and domestic ones now is leaving that equation somewhat incomplete.
