1. Livestock Digestion
Objective : Describe the functions of the major parts of the digestive system for ruminants and non-ruminants.

2. Definition care of MedicineNet.com
Accessory Organs
What is an accessory organ?
An organ that helps with digestion but is not part of the digestive tract. The accessory digestive organs are the tongue, salivary glands, pancreas, liver, and gallbladder.
Definition care of MedicineNet.com

3. Accessory Digestive Organs
An accessory organ of the digestive system is the salivary glands
Secrete Saliva
Help soften food
Make food easier to swallow
Start the digestion process

4. Accessory Digestive Organs
The pancreas is an elongated, lobed-shaped organ.
Made of two parts
Exocrine
Largest part
Produces digestive juices
Endocrine
Produces insulin that goes into the blood

5. Accessory Digestive Organs
The liver is another lobed-shaped organ that is responsible for purifying blood.
Assists in the formation of blood
Destroys exhausted red blood cells
Remember: red blood cells deliver oxygen

6. Accessory Digestive Organs
Gall Bladder
Empties waste
Secretes bile
Bile- yellow liquid that aids in digestion of lipids
Horses don’t have a gall bladder
Bile is mainly to breakdown fats and horses typically ingest less fat than other animals

7. Digestive Organs

8. The Philosophy of Digestion (partial digestion review)
What is digestion??
Conversion of “feedstuffs” into nutrients
Last stage of digestion?
Excreting unused food residues
Fecal matter

9. The Philosophy of Digestion
Digestive Processes
Mechanical
Chemical
Microbial

10. The Philosophy of Digestion
Mechanical Actions of Digestion
Mastication
Deglutition
Regurgitation
Motility
Defecation

11. The Philosophy of Digestion
Mastication
The chewing of food
Deglutition
The act of swallowing
Regurgitation
Casting up undigested food from the stomach for chewing again (cud)
Motility
Process of contracting or shrinking (squeezing food through intestines etc)
Defecation
The elimination of fecal material from the rectum

12. The Philosophy of Digestion
Microorganisms exist in the digestive compartments of ruminants
They break down the cellulose of plant cell walls
Also called roughages

13. The Philosophy of Digestion
Roughages
Cellulose of plant walls
What makes up the majority of a ruminant’s diet
Gives ruminants 60%-80% of their energy
About 60%-90% of the digestion occurs in the rumen

14. The Philosophy of Digestion
The hypothalamus glad is the gland that controls the animal’s appetite
Three things that affect appetite
Level of glucose in the blood
Amount of feed in the stomach
Environmental temperature

15. The Philosophy of Digestion
Chewing food is also called… mastication/masticating
This aids in the digestion process
Breaks down and reduces the particle size of food
Mixes food with saliva

16. The Philosophy of Digestion
What is chewing “cud?”
Occurs in ruminants
A cow will chew it’s regurgitated food
Why?
This aids in digestion
Roughages held in the rumen can be regurgitated and “re-chewed” to help digest

17. The Philosophy of Digestion
Do poultry have teeth?
NO!
How do they grind their food with no teeth?
The gizzard, an organ used to grind and crush food in chickens, turkeys, etc

18. The Philosophy of Digestion

19. The Philosophy of Digestion
Enzymes are responsible for most chemical changes in the digestive process because they speed up the biochemical reactions of digestion
A few enzymes to know
Ptyalin
Amylopsin
Sucrase

20. The Philosophy of Digestion
Enzymes
Ptyalin
Breaks down carbohydrates
Amylopsin
In the pancreas, breaks down starches
Sucrase
Another enzyme to help breakdown carbs

21. The Philosophy of Digestion
Which compartment was called the “true stomach” of a ruminant?
Abomasum
Two enzymes in the Abomasum
Pepsin
Rennin
Both are activated by hydrochloric acids and help break down proteins
Ruminant!

22. The Philosophy of Digestion
Ruminant!

23. The Philosophy of Digestion
More Enzymes…
Trypsin
Chymotrypsin
Carboxypeptidase
Help break down proteins into amino acids, which are the final product in digestion

24. The Philosophy of Digestion
…and More Enzymes…
Lipase
Breaks down fats
Bile
Secreted by the liver, breaks fats up
Steapsin
Secreted from the pancreas, finishes the break down of fats

25. The Philosophy of Digestion
In animals, minerals are dissolved in the stomach
The stomach contains hydrochloric acid
Through absorption, digested nutrients can pass from the walls of the digestive tract into the blood

26. The Philosophy of Digestion
Most absorption occurs
Carnivores and Omnivores
Small intestine
Absorbed by villi in the small intestines
Herbivores
Large intestine

27. The Philosophy of Digestion
More about Absorbing
Lymph
Absorbs fats
Blood
Absorbs carbs, proteins, water, and inorganic salts
Digestion is complete only after absorption has made the nutrients available for other parts to use

28. Assignment
Complete the rest of the notes by reviewing what you already know and using the packet that was passed out
Most of these notes will serve as a review