Grazing animals are part of a cycle. Any methane from digestion is broken down in the atmosphere and bound again to plant life and recycled. This is vastly different from drilling rock and letting out new carbon into the atmosphere at a drastic rate.
That goes to my second point; if you keep cows (or other animals) and feed them grain, and use artificial fertilizer and add other fossil-fuel dependent machinery on top of that - yes then that becomes a problem.
But it is mainly a problem if e.g. the population of cows drastically increases. In Europe and North America, it has decreased since at least the 50s; increasing in other parts of the world.
So regardless of the downvotes - "we have to stop eating red meat due to co2" is way too simplistic.