A) different animals produce different amounts of methane. Even among cattle animals, there are efforts to decrease the amount of methane they produce[0]. And nobody is laughing at those scientists and saying, "this is silly, they're still going to eat the same amount of feed so this can't possibly work." It's not just what's digested, it's how it gets digested.
B) if we have fewer cows, we don't need to replace them with the same number of another animal -- the point is we could have fewer grazing animals entirely, because our agricultural industry does not exist in order to feed wolves. We don't need to increase the number of deer by however many thousand times to sustain that ecosystem.
That was kind of my point. If you are planning on keeping the total number of grazing animals constant by massively scaling up the amount of deer, then maybe we have a problem. But why are you doing that?
If you're proposing that the current volume of cows/biomass consumption we have is a natural constant, and that other animals would just move in and take their place -- that's just not the case, we are artificially boosting the number of edible animals in the world, and by extension, we are also artificially boosting the amount of feed produced and consumed. Before the agriculture industry scaled up, we didn't have the volume of corn we currently produce lying around and being mass-consumed by deer. We started producing a lot more corn/grain and then breeding a lot more herding animals that we then fed it to.
A) different animals produce different amounts of methane. Even among cattle animals, there are efforts to decrease the amount of methane they produce[0]. And nobody is laughing at those scientists and saying, "this is silly, they're still going to eat the same amount of feed so this can't possibly work." It's not just what's digested, it's how it gets digested.
B) if we have fewer cows, we don't need to replace them with the same number of another animal -- the point is we could have fewer grazing animals entirely, because our agricultural industry does not exist in order to feed wolves. We don't need to increase the number of deer by however many thousand times to sustain that ecosystem.
That was kind of my point. If you are planning on keeping the total number of grazing animals constant by massively scaling up the amount of deer, then maybe we have a problem. But why are you doing that?
If you're proposing that the current volume of cows/biomass consumption we have is a natural constant, and that other animals would just move in and take their place -- that's just not the case, we are artificially boosting the number of edible animals in the world, and by extension, we are also artificially boosting the amount of feed produced and consumed. Before the agriculture industry scaled up, we didn't have the volume of corn we currently produce lying around and being mass-consumed by deer. We started producing a lot more corn/grain and then breeding a lot more herding animals that we then fed it to.
[0]: https://www.cbc.ca/news/technology/livestock-ghg-emissions-s...