Because of the sour flavor.

Acorn inside a tannin substance, this tannin has a kind of sour flavor, eat more will not be well digested, and inside a little toxic, then such a food is certainly not favored, very few people will eat, coupled with the people used to eat grains, acorns were replaced.

Acorn growing environment

Acorn grows on top of very large trees, the long process is relatively long, so the acorn has a symbol of patience, is a kind of efforts to positive fruit.

Acorn generally grows in subtropical broad-leaved evergreen forests, where the plant grows, the yield is very to, grows better, is the food inside the natural world, although there is food value, but now eat very few people, many people also think that the acorns are inedible things.

In folklore, acorns can be eaten as a meal when the grain fails to help people through hunger; if in the year of harvest, it can be used as fodder, livestock eat can grow meat. Acorns are rich in starch and crude protein, crude fiber and other nutrients with the composition of corn is basically the same, so acorns can be mixed with corn to make feed, you can reduce the use of corn, thus reducing the cost of feed, improve economic efficiency.