Why ruminants should re-masticate?

Answer 1

Ruminants are a group of mammals that have evolved multiple stomachs and eat a predominately vegetation-based diet (herbivores). Because these animals eat a diet with a very low caloric density, the animals need to get all the nutrients out of the food they eat. Therefore, the animals expend energy to gather and eat the vegetation then lay down or relax somewhere and regurgitate (throw up) a small portion of the grass they just ate. They then chew their cud (re-masticate that small portion) to break down the tough undigestible plant fibers and release the digestible sugars from the inside of the plants. Without chewing their cud, these animals would not be able to get enough calories from the food they eat to support a healthy life.