Deer: The members of the deer family are ruminants, having a four-compartmented stomach, which allows the deer to feed very rapidly, chewing its food just enough to swallow it. This partially chewed food goes into the storage section of the stomach known as the rumen. A feeding deer is at a disadvantage because while feeding it cannot be alert to danger. Not having to masticate its food thoroughly, the deer can fill its paunch rapidly and then retire to a safe place to do the job properly. When the deer is ready, it regurgitates a ball of partially chewed food about the size of an orange and rechews it. it then reswallows the food, which now enters the second section of the stomach, the reticulum. From there, it goes into the omasurn, then through the abomasum into the intestines where digestion is completed. Sheep i am not so sure about.

"A ruminant, from a physiological point-of-view, is any artiodactyl mammal that digests its food in two steps, first by eating the raw material and regurgitating a semi-digested form known as cud from within their first stomach, known as the rumen. The process of again chewing the cud to break down the plant matter and stimulate digestion is called ruminating. Ruminating Mammals include cattle, goats, sheep, giraffes, American Bison, European bison, yaks, water buffalo, deer, camels, alpacas, llamas, wildebeest, antelope, and pronghorn. However, from a zoologial and evolution point-of-view, the suborder Ruminantia includes all those species except the camels, llamas and alpacas, which are Tylopoda. Therefore, 'Ruminant' (physiology) is not synonymous of Ruminantia (taxonomy)." "Ruminants have a fore-stomach with four chambers. These are the rumen, reticulum, omasum, and abomasum. In the first two chambers, the rumen and the reticulum, the food is mixed with saliva and separates into layers of solid and liquid material. Solids clump together to form the cud (or bolus). The cud is then regurgitated, chewed slowly to completely mix it with saliva and to break down the particle size, Fiber, especially cellulose and hemi-cellulose, is primarily broken down into the three volatile fatty acids, acetic acid, propionic acid and butyric acid in these chambers by microbes (bacteria, protozoa, and fungi). Protein and non-structural carbohydrate (pectin, sugars, starches) are also fermented." Source and further information: http://en.wikipedia.org/wiki/Ruminant Further information: http://www.kerrlake.com/deer/white2.htm http://www.ansci.cornell.edu/4H/meatgoats/meatgoatfs14.htm http://encarta.msn.com/media_461542267/Four-Chambered_Stomach.html

They are all ruminants and have the same 4 compartment stomachs.