Ruminants are mammals of the order artiodactyla and are capable of digesting plant based foods by initially softening the consumed material which takes place in the animal's first compartment of its alimentary tract. Ruminants have a four compartment stomach and the different compartments are the rumen,reticulum,omasum and abomasum. Fermentation of ingesta takes place in the rumen. Digestion/fermentation in the rumen takes place by the action of microbes mostly bacteria, however there are some protozoa,fungi and yeasts. Fiber such as cellulose and hemi-cellulose are degraded to volatile fatty acids these include acetic acid propionic acid and hydrobutyric acid. Fermentation of proteins and non-structural carbohydrates also takes place within these chambers.Three major categories of ruminants are recognised based on their feed type and feeding habits.Concentrate selectors,intermediate types and grass/roughage eaters.Guniea-pigs, horses and rabbits are not grouped as true ruminants since they have simple single-chambered stomach and they digest cellulose via an enlarged cecum allowing easy digestion of fibrous materials and are reffered to as hindgut fermenters.