No matter what you feed them, compared to other livestock animals cows are a fairly inefficient at turning feed into meat, meaning you need to dedicate more land to agriculture when it could be forest instead and thus a better carbon sink.
I don't understand why most people have this wrong idea. In a lot of places, the grazing pastures are naturally occurring, they aren't planted there.
It feels like people want to destroy the natural landscape of countries like Argentina, just because it's now fashionable to say they don't eat meat.
Even goats, everyone goes around claiming they have such an ineficient CO2/Kg meat index. Well, around here, goats are fed almost all the year by going into the forest and cleaning the shrubs and small vegetation there... besides feeding the goats for free, it also cleans the forest for free: something we would have to do otherwise in order to prevent fires in the summer.
There are, as far as I know, regions where the soil is only capable of growing pasture, hard to plant trees in.
> There are, as far as I know, regions where the soil is only capable of growing pasture, hard to plant trees in.
I assume that those areas would not be sufficient to cover current meat and dairy demands. If they were there wouldn't be any deforestation or soy fields for animal feed. And non-grazed grasslands is still going to release less methane than grazed lands.
Regarding deforestation and so on, I think we must also take into account that "industrialized" non-pastured husbandry (is that the correct term?) is probably cheaper and easier than the greener alternative.
Sadly, it's usually a matter of profits and not a matter of environmental friendliness.
When's the last time the Midwestern plains area of the United States was forest? Before the beef industry, 50-100 million bison roamed the plains. It turns out that ruminants like bison and cows are essential components of a grassland ecosystem.