Animal Digestive System (Note-Taking Guide) Topic # 3024 Ms. Blakeley.

Animal Digestive System(Note-Taking Guide)

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Topic # 3024

Ms. Blakeley

Digestive System – Objectives

Describe and understand the basic functions of the primary components of the digestive system.

Compare the functions and locations of the digestive organs in man, poultry, horses, cows and swine.

Differentiate between and identify digestive systems of man, horses, swine, poultry and cows.

Digestive System

Where large complex molecules are broken down into simpler molecules

Digestive Tract:– Long tube beginning with mouth and ending with the anus

_________________ (Ruminant)– A stomach with more than one compartment

• (cows, sheep, deer)

_______________ (Non-ruminant)– A stomach with one compartment

• (swine, horses)

___________ (Poultry)– No true stomach

• (chickens, geese)

Digestive Systems

_______ & ______ have a simple stomach with an extensive intestinal system

__________ & _________ have a simple stomach with an extensive intestinal system and an enlarged caecum

____________ have a complex stomach with a simpler intestinal system

___________ have no teeth and no true stomach with a crop and gizzard to grind food

Mouth & Esophagus Mouth: “prehensile” tool (grasps & mixes food)

– Chewing breaks down food– Salivary Glands secrete juices containing enzymes

(digest food)– Mucin lubricates the feed for swallowing

Esophagus: muscular tube that connects mouth to stomach– Peristaltic waves send feed down the esophagus,

(muscle contractions).– Reverse Peristalsis = blowing chunks– The cardia, located at the end of the esophagus

prevents feed in the stomach from coming back into the esophagus. ( non-ruminants only)

Simple Stomach

Muscular organ, receives feed Gastric juices are secreted by the glands in

the stomach wall– start when masticated feed enters the stomach– Gastric juices have about 0.2 to 0.5 percent HCl

The wall of the stomach is lined with muscle, this muscle churns and squeezes the feed– This action forces the liquid portion on into the

small intestine

Ruminant Stomach Occupies 3/4 of abdominal cavity, mostly

on the left side _________ (paunch): 80% of stomach,

lighter food collects here– Microbes digest cellulose– Uses lots of water

_______________ (hardware stomach): 5% of stomach, heavy foreign items are trapped here

Ruminant Stomach (cont.)

__________ (many plies): 8% of stomach, absorbs water

______________ (true stomach): 7% of stomach, typical enzyme activity

Rumination= regurgitation, re-chewing of food

Rumination (regurgitation)

After rumen if full, it lies down to ruminate (chew its cud)

Cattle spend from 5-7 hours ruminating, broken up into 6-8 periods

Regurgitation is the process of forcing the feed back into the mouth for chewing

Done through a series of muscular contractions and pressure in the rumen and reticulum

Avian stomach/gizzard

Since chickens have no _____, they swallow food whole and it’s stored in the _______

Feed in proventriculus are secreted by the glandular stomach and mixed with feed

The feed moves to the _______and is ground Epithelium breaks the feed into smaller

particles, further mixing proventricular digestive juices with the feed in the gizzard

The end of the digestive system is the vent

Small & Large Intestines Small Intestine: long coiled tube

connecting __________ to large intestine– rest of the digestion and absorption takes

place here– surface covered with villi (surface area)

Large Intestine:_________, colon, rectum– absorbs water (makes feces more solid)– some vitamins & minerals absorbed here– Cecal Fermenters (Horse): similar to rumen