Don't livestock mostly eat food humans cannot eat?
The short answer
Partly true. Most livestock feed by weight is grass and crop residues. But a large share of the world's grain and almost all soy meal goes to animals, and the land used is enormous either way.
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Sample data. The figures and sources on this page are demonstration records showing how evidence will be presented. They are approximate and have not yet been through our review process. Read about how we will verify evidence.
The claim
“Cows eat grass and pigs eat scraps, turning things we cannot eat into food we can. So livestock add to the food supply rather than competing with it.”
Why this question comes up
- It is true for traditional grazing and for some by-products.
- It is a common industry talking point.
What the evidence says
Livestock use around three-quarters of the world's farmland, including grazing land, and supply under a fifth of calories.
Roughly a third of global cereal production is fed to animals. More than three-quarters of soy is fed to animals.
Chickens and pigs, which make up most farmed animals, cannot live on grass. They are fed mostly grain and soy that could feed people.Source 1: Reducing food's environmental impacts through producers and consumersSource 2: Drivers of deforestation: soy, and what it is used for
Weighing the claim
What is true about the claim
- Ruminants on natural pasture do convert inedible grass into food, and some grazing land cannot grow crops.
- By-products like brewers' grains and oilseed cake are a genuine use of material that would otherwise be waste.
What may be misleading
- The argument fits cattle on marginal land, not the intensively farmed chickens and pigs that provide most meat.
- Even where livestock eat inedible material, the land they occupy has an opportunity cost: it could store carbon as forest or support wildlife.
What remains uncertain
- How much grazing land could realistically be restored to other uses, and what the trade-offs would be for rural livelihoods.
Bottom line
True for some cattle and sheep, not for most of the animals we eat. Overall, livestock are a net consumer of land and crops, not a way of making food from nothing.
Evidence strength
Why this rating: Feed composition and land-use data are robust globally, but vary a great deal between regions and systems.
Supported by good-quality studies that point the same way, but with gaps: fewer studies, mostly observational data, or some inconsistency.
Claims behind this answerEach claim has its own record with rating, methodology and sources.
Livestock uses around three-quarters of the world's agricultural land while supplying under a fifth of its calories.
Most farmland feeds animals, not people directly. That land delivers a relatively small share of our food.
More than three-quarters of the world's soy is fed to livestock; only around 7% is eaten directly by people.
Soy grown for tofu and soy milk is a small slice of the total. Most soy feeds chickens, pigs and cows.
Sources
Each source links to our record of what it found, its limitations and what we used it for, with a link to the original.
- 1Reducing food's environmental impacts through producers and consumers
Joseph Poore, Thomas Nemecek (2018). Science.
- 2Drivers of deforestation: soy, and what it is used for
Hannah Ritchie (2021). Our World in Data.