i was asking because i can explain the methodology, and it is dubious.
if you total all the inputs that go into a product (the water, the carbon emissions, the land use, etc), then you can see what it would cost to produce it if you made no other products. but that’s not actually the environment in which meat dairy and eggs are produced.
the most illustrative example is cotton. cotton is not a food. it is grown for textiles. it wrecks the soil and it is THIRSTY. after you harvest the cotton and separate the fiber from the stalk and seed, you have seed left over. way more seed than you need to replant. cottonseed can be and is pressed for oil, but it takes much less processing to mix it into cattle fodder. why should the water used to grow cotton count against the water inputs for beef and milk? it’s actually a conservation of resources. these industries are all interconnected, and trying to just put a singular value on every product in the absence of the context of its production is not actually useful in determining what would be ecologically responsible.
that graphic shows that the feed that is given to animals is almost entirely the industrial waste from oil production. it’s called “soy meal” or “soy cake”
looks to me like cattle get very little of the global soy crop, and most of what is fed to livestock is, as i said, the parts of the plant left over after we’ve taken what we want for ourselves.
most cows mostly eat grass for most of their lives. whole corn is fed as a treat to entice them to eat the rest of the silage it’s sprinkled on (in my experience).
whole corn and soybean are some of the primary cattle feed. The majority of all soybean grown in North America is used as cattle feed and corn is a large market segment.
a lot of what we give to animals as feed is parts of plants we can’t or won’t eat,like silage. if we grow and use the part of the plant we want,and we can reclaim some more of the resources through animals,that’s good.