cows and stomachs

[chocolatecaz]

why does a cow have four stomachs?

[pinus]

google query on cow stomach has this as the first reference http://www.benjerry.com/our_company/research_library/product ion/cow.html

[JohnPPotts]

Basically, cellulose (the constituent of plant cell walls) is hard to digest (humans don't, it goes "straight through" us): as cows eat a lot of grass they have evolved (or been handed a God-given) a system for breaking it down. It's just quite complex!