[dTal]

Did they? Did anyone measure that? Or is that simply an assumption? Relatively small dietary changes can greatly reduce the amount of methane produced by cows (I believe you add something like 15% seaweed to the feed), so it's not at all clear that a free range bison would be similar.

[ryathal]

Wild Bison aren't eating seaweed in the great plains. Cows in the plains spend their majority of their life eating the same grasses that the bison ate, then they spend a few months on a corn diet.