A cow eats grass for over 6 hours a day! In order to digest the grass, which is very strong, the cow has evolved 4 stomach chambers to digest the grass. The four sections are all help the cow digest the grass. First, the cow eats grass and the grass is stored inside of the first two stomachs. Then, the grass empties out into the third and fourth stomachs which use digestive acids to break down the grass further and convert it into nutrients. Without these sections, the grass will not be fully digested and the cow would not be able to get the nutrients out of it. That is why cows have four stomach sections!