It is very tempting to start ranting in this write-up, but I try to keep it as objective as possible. Amoeba Protozoa says an even greater contributor to global warming
Greater than what? Cars, the industry, humans, human activity? Any percentages? Ok here some from the IPCC website:
“... In 1990, the three largest sectors of energy consumption were industry (45% of total CO2 releases), residential/commercial sector (29%) and transport (21%). Of these, transport sector energy use and related CO2 emissions have been the most rapidly growing over the past two decades. ...”
In other words: 100 - 45 - 29 - 21 = 5% for the remaining sectors, livestock, among other things.

Secondly, cows fart mainly CO2 and methane (CH4) because of the anaerobic fermentation in the stomachs, not stuff like ozone. And a cow is an animal, not an efficient bioreactor. IIRC cows have an overall contribution of 5% to the greenhouse gases.

Last: if you (I mean you-in-general, not you-AP) are still thinking about a vile beast, despite the <5% contribution, why don’t you reduce the consumption of hamburgers, steaks etc.? There are a lot of cows because the public eat its meat, not because the farmer adores the cute cuddly cows.