A Comparison of Mammalian Alimentary Systems

Obtaining and transporting nutrients is a vital function for all multicellular organisms and different species have evolved some interesting ways of gaining, storing and digesting their nutrients.

Hindgut fermenters Amongst herbivores, for example, almost all have cellulose digesting bacteria within their gut that live symbiotically, assisting with the break down of vegetation. Some are classified as “hindgut fermenters”, which have microbes and fermentation in their hindgut, the caecum and proximal colon. These animals are less effecient at digesting their food and can sometimes be observed practising coprophagy (eating faeces).  Horses  Koalas Foregut fermenters Other herbivores are “foregut fermenters”, or ruminants, which have pouches with microbes in the stomach. These microbes consume glucose from cellulose but produce fatty acids that the animal can use for energy. Microbes can also be digested further along the digestive tract as they are also a source of protein. Foregut fermentation, or rumination, is a slower digestive process, but has the advantage of providing more nutrients and wasting less energy. Foregut fermenters include:  Cattle  Kangaroos and Wallabies Ruminants digest plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again. The process of rechewing the cud to further break down plant matter and stimulate digestion is called "ruminating".

Good information about different types of digestive systems from a UK Veterinary site, Comparative Digestion. http://vetsci.co.uk/2010/05/14/comparative-digestion/# Pig

Describe the diet of pigs. Are they herbivores, carnivores or omnivores? Are they foregut or hindgut fermenters?

Sheep Describe the diet of sheep and how they feed. Are they herbivores, carnivores or omnivores? Are they foregut or hindgut fermenters? Koala

Describe the diet of Koalas and how they feed. Are they herbivores, carnivores or omnivores? Are they foregut or hindgut fermenters?

Dog Describe the diet of dogs and how they feed. Are they herbivores, carnivores or omnivores? What is the major differences between a canine alimentary tract and a herbivore alimentary tract. In what part of the alimentary tract does most of the digestion occur?

Vampire Bat

http://www.batsnorthwest.org/BNWFall07.pdf

Describe the diet of vampire bats and how they feed. What provides most of the volume of their food ? What provides the majority of their nutrients . Where is this digested? Humans

Label each part of the human alimentary tract indicating the function of each .