this post was submitted on 13 Aug 2023
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animals are fed parts of plants that people can't or won't eat. and cows eat mostly grass.
Yeah and no. Cows eat about 2% of their weight each day. Over 98% of this comes from food that we grow for them. It's true that a lot of it we humans wouldn't eat, but we still grow it for them to eat. The idea of cows eating grass in a field and that's what they eat is extremely rare.
For the US as a example less than 1% of the cows feed is grass. The majority of things like soy (77% of what is grown and we could eat) goes to cow feed.
"There were about 92 million head of cattle in the United States at the end of 2015, with roughly 30 million head slaughtered that year. For perspective, the grass-fed industry currently slaughters about 230,000 head, or less than 1% of the total conventional slaughter."
If we take 7% of all soy out because it's fed directly to animals, and another 6.9% is eaten, but not as oil, and 20% of each of the remaining beans are made of oil, we find 17.22% is the maximum amount of oil we could get if all the soy beans not fed to animals or eaten by people are pressed for oil.
It turns out that the chart shows 13.2% is oil for humans to eat, and 4.0% is used industrially (and these are all oil uses), totaling 17.2%,then basically all soy not eaten directly by animals or as various human foods is pressed for oil.
source https://ourworldindata.org/uploads/2021/02/Global-soy-production-to-end-use.png
"grass fed" means they aren't grain-finisged, but most of their diet is grass until they get to the feedlot.
almost all soy is pressed for oil. what is fed to livestock is almost entirely industrial waste from that process.
Using it to make plant-based meat alternatives or tofu or soy milk would be more efficient than feeding it to animals, where most of the nutrients and calories are used up by their metabolism.
yea. we do. but we don't use all of it for human food. i don't see anything better to do with the industrial waste than feed it to livestock.
After extracting the protein and nutrients for plant-based products there's not much nutrition left to use it as animal feed though. It's probably not nutritionally appropriate for cows, pigs and chickens at that point. Using it for insect farming would seem more realistic to me, or as a growth medium for edible mushrooms.
when you have a ton of soy cake, I guess you can decide what to do with it.
almost no soy goes to cattle at all
beef cattle eat mostly grass for most of their lives