a cow chews the grass it is eating thoroughly and slowly, so it is chewing it's cud - the masticated grass in it's mouth. - that's where the expression for long, contemplative thinking when trying to solve a problem comes from.
A donkey is NOT a cud-chewing animal.
The times you see them chewing are when they are chewing their cud.
It means loitering or socializing, or just plain "chillaxing."
"To chew the cud" is "ruminer" "The cud" is "la panse" A cud-chewing animal is "un ruminant"
It just means you can hear the cow chewing whatever she's eating or chewing her cud.
If you are asking why they call it that, it could be because some people look like like they are chewing their cud while they are chewing gum. Cud it regurgitated feed that the cow then rechews.
Ruminants
Yes.
Ruminate.
No. Zebra are close cousins to horses, which are not cud-chewing animals because none of them have four chambers in their stomachs; just one simple stomach.
A lump of chewing tobacco is called a quid. A variant of the word: cud quid - (noun) a lump of chewing tobacco
Cud. Cows regergitate grass and it is call cud. Hence cows chew their cud.