I mean the stuff is everywhere, almost every herbivore eats it.
Why isn’t it a staple in the human diet?
We eat all kinds of grasses: corn, oats, wheat, barley, rye.
Sorry, I’m talking grass like in your front lawn
There is not a lot of nutrition in the kinds of grass cows and such eat. That is why cows have a four chambered stomach and chew their cud. In this way they can extract as much nutrition as possible from the grass. Humans are not built to do that.
We then eat the cow which has turned the grass into meat we can eat.
Humans have a single chambered stomach and a small, nearly useless cecum. We cannot digest grass.
Animals that graze and digest grass either have a large cecum (horses, rabbits) or a multi-chambered stomach (cows, goats) that facilitates digestion of grass.
because we’re not herbivores. we aren’t built to extract much if any nutrition from it. and the ones we do eat, we only eat the starchy seeds.
edit:
and gut flora which can take the bulk of grasses which the animals still can’t digest directly and convert it into useful nutrients.
Those plants may be grass-related, but we don’t eat the leaves, we eat the seeds. Cows eat the leaves. They’re able to digest the cellulose in those leaves; we aren’t.
Digestive issues aside, there’s also the mastication; grass contains a lot of silica, which would have a similar effect on your teeth to chewing fistfuls of sand. Grazing animals have teeth that continually grow; a human eating lots of grass would be toothless very quickly.
What kayaker and Whack-a-mole said. Humans can eat the seeds of grasses without too much trouble but we lack the equipment necessary to digest the high fiber portions of the grass plants. It’s worth noting the domesticated grains we now grow and consume in great quantities millennia ago more closely resembled the grasses that grow in one’s lawn. Over time we’ve selected those plants that had the most abundant seeds and propagated them.
As said above, you can, but it would require a grass to human food converter to make it suitable for human consumption, one such model is called a cow, others like sheep and goats are also widely available and IMHO a bit more tasty.
as Solzhenitsyn writes in One Day in the Life of Ivan Denisovitch, the Russian authorities at that gulag fed the prisoners boiled grass. This seems to have been mainly to give them something to fill their bellies, rather than for nutrition, because as he (and people above) have pointed out, humans can’t digest non-cereal grasses (and only parts of those). One Day is fiction, of course, but it’s drawn from experience, so I assume that the Russians actually did feed prisoners grass.
I hasten to point out that this is held up as one of the bad things they did.
One book I read said that the major diversion between humans and chimps was that we developed fire, cook our food, and also eat a lot of protein (meat) - which is already partially broken down by cooking. As a result, where a chimp must chew plants for 6 hours a day to get enough nutrition, we get the same with an hour a day of chewing.
What grass lacks in food value, animals make up for it by eating volume. Cows for example spend a substantial amount of time grazing. (I think I read that actually, the cow chews their cud which works its way through the stomachs where a stomach bacteria turns cellulose into usable nutrition. Hence the need for large holding areas for the bacteria to do its work.)
Short answer - for the same reason we don’t just survive on green salads alone.
Note that rabbits also, errr, “recycle” their feces. So the grass takes two passes thru their digestive system. Still, I don’t thinking “recycling” our waste will add much nutrition.
Also, some browsers will actually starve on a winter time diet of too much bark and such. Even herbivores can’t digest some plant materials well.
A wealthy lawyer was riding in his limousine when he saw two men along the roadside eating grass. Disturbed, he ordered his driver to stop and he got out to investigate. He asked one man, “Why are you eating grass?”
“We do not have money for food,” the poor man replied.
“Well, then, you can come with me to my house” the lawyer said.
“Sir, I have a wife and two children with me.”
“Bring them along,” the lawyer replied.
Turning to the other poor man he stated, “You come with us also.” The second man then, in a pitiful voice said, “Sir, I also have a wife and we have six children with us!”
“Bring them all as well,” the lawyer answered.
They all entered the car, which was no easy task, even for a car as large as the limousine. Once underway, one poor fellow turned to the lawyer and said, “Sir, you are too kind. Thank you for taking all of us with you.”
The lawyer replied, “Glad to do it. You will love my place. The grass is almost a foot high.”
Herbivores will very often starve to death with full stomachs. There’s almost always some sort of low quality plant material to eat, the question is if that plant material contains enough nutrition to avoid starvation.
As I said in the other thread a few months ago, we look around out the window and see all these plants and figure that herbivores have it made. Except most plant material isn’t worth eating. Herbivores spend a lot of time selectively eating only the highest quality plant parts, they won’t just gobble down everything unless they have no choice. That would be like filling up on Styrofoam that has to pass through your system before you can eat nutritious food.
It should also be pointed out that large herbivores like cattle pretty much spend their entire waking life eating or chewing cud. I personally like having free time.
A better comparison might be gorillas. Chimps eat a lot of high-energy foods like fruit and meat when they can get it. Gorillas are more herbivorous, and have huge guts where they can break down plant material. (But even gorillas can’t eat grass as a general thing. They select plant material with a relatively high nutritional content and less roughage.)
Yeah, and all the nutritious stuff is just out of reach on the other side of the fence!!
In the Philippines, you can buy a can of “grass jelly” – which is gelatinized liquid left after boiling grass. It tastes like, well, grass. It’s cheap, and cubes of it are used to add body to cool drinks.
http://hongaustralia.com.au/wp-content/uploads/2014/03/35012-EAGLE-GRASS-JELLY-CAN-530G-800x800.png