The Digestive System

Learning Objectives

• List the three types of digestive systems for animals.

• Describe the function of the digestive system.

• Name the parts of the digestive system in poultry and explain their function.

Types of Digestive Tracts

• Monogastric: one stomach

• Ruminant: multiple chambers

• Modified Monogastric: poultry/birds

Function of Digestive Tract

• Provide nutrients to the body

Modified Monogastric Poultry/Birds

Mouth (beak)

• No teeth – replaced by beak

Esophagus

• The tube that connects the mouth with the rest of the body

Crop

• Located in the neck region of the bird

• Part of the esophagus

• Used to store food until the bird is ready to digest more food

• Food is softened by saliva and secretions from the crop wall

Proventriculus

• True Stomach

• Secretes enzymes

• Passageway between crop and gizzard

Gizzard

• Unique to birds

• End of stomach before duodenum

• Made up of two smooth muscles

• Contains grit which acts as the birds teeth

• Feed is crushed and mixed with digestive juices

Small Intestine

• Made up of two parts

– duodenum

– lower small intestine

• Important to absorb nutrients

Ceca

• Have no real function

Large Intestine

• Additional absorption of water

Pancreas

• Located in the center of the duodenal loop

• Secretes pancreatic juice which neutralizes the enzymes secreted by the Proventriculus

• Helps break down fat

Liver

• Produces a dark green substance called bile

• Bile is necessary for the absorption of fat

• Bile is stored in the Gall Bladder

Cloaca

• The end of three different tracts– digestive

– reproductive– excretory