The grazing animals like cows, buffaloes etc. are known as:
Ruminants
Ruminants are mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialised stomach prior to digestion, principally through microbial actions. For example, cows and buffaloes.These animals have four bags to store the food instead of one and they chew their food several times before sending it to the intestine.