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
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•
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•
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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