The oxygen part of this claim is obvious and funny but also the bison part is wrong…

Or rather the diet they eat.

Feeding cows energy dense foods like grain produces more emissions, like more than 3x the emissions of a grass-based diet.

And wild bison produce even less when eating a wild diet because that’s what they fucking evolved to eat and digest efficiently so yeah you could massively greater numbers of bison with less emissions.

Even just feeding cows on grass instead of enriched grain that they can digest better would be a huge reduction in emissions.

Or, you know, eat the grain instead of feeding it to a cow.