Assuming you grow something other than grass on that pasture to eat (also assuming it isn't marginal land which makes up 2/3 of agricultural land), wouldn't that other plant extract approximately the same amount of calories from the sun? And wouldn't the bioavailability of that plant also be lesser than that of meat?
First, most cows are not grass fed. They are largely fed things that have bioavailable calories for humans, like soy. Likewise, chickens mainly consume corn.
Second, farm animals are not 100% efficient in absorbing calories and converting them to meat calories, so the 25x going from grass to beef is meaningless, assuming you were attempting o make some connection to my 25x figure on beef production efficiency.
Third, agricultural land is not all used for meat, and I'd need a source for that 2/3 being marginal figure. Looking it up I see ~2/3 (60%) of ag land is used for beef, but it is not all marginal. Beef is the main cause of Amazon deforestation for example.
Forth, if we just go by land use to globally consumed calories, cows, despite using 60% of ag land, only make up 2% of consumed calories. If we make an absurd assumption that 50% of all calories come from non-farmed sources, that still leaves 40% of ag land producing 48% of the world's calories in comparison, which would include non-beef meat as well.
Finally, just because the land wouldn't have much use to humans if we didn't use it for cows, doesn't mean it wouldn't benefit the planet, and us, if we stopped using it for such.
from this anecdotal source: https://www.reddit.com/r/explainlikeimfive/comments/sbfn6b/c...
1lb of grass to humans = 32kcals / lb
1lb of grass to cows = 800kcals / lb
800/32 = 25x
Assuming you grow something other than grass on that pasture to eat (also assuming it isn't marginal land which makes up 2/3 of agricultural land), wouldn't that other plant extract approximately the same amount of calories from the sun? And wouldn't the bioavailability of that plant also be lesser than that of meat?