Differentiate between the digestive systems of the sheep and poultry. Illustrate your answers with clearly labelled diagrams.
The sheep is a ruminant herbivore, whereas poultry is a non-ruminant bird. The sheep is adapted for microbial digestion of fibrous feeds and chewing of cud; poultry is adapted mainly for rapid digestion of grains and other concentrated feeds.
Labelled diagrams of the alimentary canals
Fig. 1: Digestive system of a sheep (ruminant).
Fig. 2: Digestive system of poultry (fowl).
Differences between the digestive systems
Feature
Sheep
Poultry
Type of feeder
Ruminant, adapted to grazing and roughage.
Non-ruminant bird, adapted mainly to grains and other concentrated feeds.
Mouth and teeth
Has teeth for biting and grinding food. It later regurgitates and rechews cud.
Has a beak and no teeth. Food is swallowed without chewing.
Crop
No crop.
Crop present for temporary storage and softening of food.
Stomach
Has a four-compartment stomach: rumen, reticulum, omasum and abomasum.
Has a glandular stomach, the proventriculus, followed by a muscular gizzard.
Grinding of food
Food is ground by molar teeth during mastication and rumination.
Food is ground in the thick muscular gizzard, often with swallowed grit or small stones.
Cellulose digestion
Micro-organisms in the rumen digest cellulose and other fibrous materials.
Cellulose digestion is very limited; only slight fermentation occurs in the paired caeca.
Caeca
Has one caecum.
Has two caeca.
Terminal opening
The alimentary canal ends at the anus.
The digestive, urinary and reproductive tracts open into the cloaca, which opens at the vent.
Food pathway in sheep: mouth → oesophagus → rumen/reticulum → omasum → abomasum → small intestine → large intestine → anus.
Food pathway in poultry: beak → oesophagus → crop → proventriculus → gizzard → small intestine → paired caeca → large intestine → cloaca → vent.
The sheep is a ruminant herbivore, whereas poultry is a non-ruminant bird. The sheep is adapted for microbial digestion of fibrous feeds and chewing of cud; poultry is adapted mainly for rapid digestion of grains and other concentrated feeds.
Labelled diagrams of the alimentary canals
Fig. 1: Digestive system of a sheep (ruminant).
Fig. 2: Digestive system of poultry (fowl).
Differences between the digestive systems
Feature
Sheep
Poultry
Type of feeder
Ruminant, adapted to grazing and roughage.
Non-ruminant bird, adapted mainly to grains and other concentrated feeds.
Mouth and teeth
Has teeth for biting and grinding food. It later regurgitates and rechews cud.
Has a beak and no teeth. Food is swallowed without chewing.
Crop
No crop.
Crop present for temporary storage and softening of food.
Stomach
Has a four-compartment stomach: rumen, reticulum, omasum and abomasum.
Has a glandular stomach, the proventriculus, followed by a muscular gizzard.
Grinding of food
Food is ground by molar teeth during mastication and rumination.
Food is ground in the thick muscular gizzard, often with swallowed grit or small stones.
Cellulose digestion
Micro-organisms in the rumen digest cellulose and other fibrous materials.
Cellulose digestion is very limited; only slight fermentation occurs in the paired caeca.
Caeca
Has one caecum.
Has two caeca.
Terminal opening
The alimentary canal ends at the anus.
The digestive, urinary and reproductive tracts open into the cloaca, which opens at the vent.
Food pathway in sheep: mouth → oesophagus → rumen/reticulum → omasum → abomasum → small intestine → large intestine → anus.
Food pathway in poultry: beak → oesophagus → crop → proventriculus → gizzard → small intestine → paired caeca → large intestine → cloaca → vent.