Digestion and Absorption in Ruminant and Non-ruminant by Assistant Professor Boby Basnet

1. Animal Nutrition and Feeding Practices
Boby Basnet
Assistant Professor
Animal Nutrition and Feeding Practices
Ilam Community Agriculture Campus
Purbanchal University

2. Digestion
• Digestion is a complex process involving specialized
anatomical and physiological adaptations for the
absorption of nutrients.
• Digestion is the breakdown of large insoluble food
molecules into small water-soluble food molecules
so that they can be absorbed.
• The digestive system includes the digestive tract
and its accessory organs

3. Depending upon the structure of digestive tract,
animal can be classified into three groups:-
A. Monogastric B. Ruminant
C. Hind gut fermenter (rabbit, horse)
According to the feeding habit domestic animas are
grouped into-
a. Carnivorous b. Herbivorous
c. Omnivorous

5. Digestion process
A. Mechanical: mastication, chewing of cud and
contraction of alimentary canal
B. Chemical: enzymatic digestion
C. Microbial: bacteria and protozoa involved in
digestion

6. Horse digestive system

7. Digestive system of non-ruminant
• Swine

8. Poultry

10. Digestion in non-ruminant
• Digestion:
is mechanical, mastication, muscle contractions
is chemical, enzymes soften and break down
macromolecules of food
The small fraction of cellulose and hemicellulose are
digested by microorganism in large intestine (caecum).

11. Digestion in pig
1. Digestion in mouth: prehension, mastication and
swallowing. Saliva contain α-amylase (ptyalin) but no
digestion in mouth because food is quickly swallowed.
2. Digestion in stomach:
 Gastric juice, Liver and pancreatic juice and Intestinal juice
help in digestion of carbohydrate, proteins and fats.
3. Digestion in large intestine
It secrets mucus not enzyme. The small fraction of
cellulose and hemicellulose are digested by
microorganism(fermentation in caecum) which produce
volatile fatty acid like acetic acid, propionic and butyric
acid

12. Poultry digestion
1. Mouth: Saliva and digestive enzymes are added, doesn’t
have teeth to chew
2. Pharynx and esophagus: common passage for feed and air
3. Crop: food is moistened and Little digestion with salivary
amylase
4. Proventriculus: true stomach, responsible for the
production of gastric juice
5. Gizzard: crushing and grinding the feed particles
6. Small intestine: digestion by intestinal juice, pancreatic
juice and bile
7. Caeca: Digestion with the help of bacterial action
8. Large intestine: maintain water balance by water
absorption
9. Cloaca and vent: cloaca is located at the end of the
intestine and external opening of cloaca is vent

13. Digestive enzymes
A. Carbohydrate digestive enzymes
name Sources Substrate (enzyme act
upon)
α-amylase Saliva Starch, glycogen, dextrin
Sucrase Small intestine Sucrose
Maltase Small intestine Maltose
Lactase Small intestine lactose
Trehalase Small intestine Trehalose
Oligo-1,6
glycosidase
Small intestine Dextrins

14. 2. Proteolytic enzyme
3. Lipolytic enzymes
Name source substrate
Gastric lipase Gastric mucosa Fats and other organic esters
Pancreatic lipase pancreas Fats and other organic esters

17. Digestion in ruminant
1. Carbohydrate digestion in ruminant
• The major portion of ruminant’s diets consist of
roughages contain cellulose, hemicellulose and
other carbohydrate
• When these carbohydrates reach to rumen, these
are then subjected to break down by enzyme
secreted by rumen microorganism, and gives
volatile fatty acids and gaseous like CO2 and
methane.
• The normal concentration of bacteria in rumen
liquor is 1011 and protozoa are 106 per ml of
rumen content

18. • The main end product of carbohydrate break
down in rumen is acetic acid, propionic acid and
butyric acid.
• Most of the acid produced is absorbed directly
from rumen, reticulum and abomasum.
• Major gaseous produced after carbohydrate
digestion are carbon dioxide, methane and
hydrogen. Most of these gaseous are lost by
eructation or belching.

19. • Composition of Volatile fatty acid in rumen
Acetic acid (CH3C00H): 60-70%
Propionic acid (CH3CH2COOH): 15-20%
Butyric acid(CH2CH2CH2COOH): 10-15%
Valeric acid and Isovaleric acid are also produces in trace
amount.
Composition of gas in rumen
Carbon dioxide: 40%
Methane: 30-40%
Hydrogen: 5%
Oxygen and nitrogen in small amount ingested from air.

22. 2. Protein digestion in ruminant
• After utilization of product of carbohydrate
digestion, synthesis of microbial protein available
to the host for subsequent digestion in lower gut.
• Rumen microbes break down the degradable
intake protein (DIP) into peptides, amino acid and
ammonia which are used by the microbes for
growth and reproduction.
• Some of the amino acids are further degraded by
deamination to organic acid, ammonia and CO2.

23. • Excess ammonia is absorbed via the rumen wall
into the blood and converted into urea in the liver
• When microbes pass in abomasum and small
intestine, they are digested by digestive enzymes
and make microbial cell protein available to host.
Note
• Un-degradable Intake Protein (UIP): escapes rumen
microbial breakdown and digested by enzymes in
intestinal region

24. Bypass protein
Dietary protein that escapes rumen microbial breakdown and
passes to abomasum without any major biochemical changes.
These are also termed as rumen un-degradable protein(UDP).
Need of by-pass protein:
• For high yielding animals, the microbial protein synthesized in
rumen is not adequate to meet the total amino acid requirement
and so it has to be supplemented with the pass –protein.
• The total amino acid obtained from microbial protein is just
sufficient to yield not more than 10 liters of milk per day
• eg of UDP; animal protein sources, cotton seed meal, soybean,
sunflower seed and heat, formaldehyde, tannin treated feed etc.

27. Digestion of lipid
• Lipids are hydrolyzed to fatty acid and glycerol.
Lipolytic enzyme produced by bacteria involves in
this lipolysis.
• The glycerol is further fermented to propionic
acid. Unsaturated fatty acids are hydrogenated by
the microorganism.
• All short chain fatty acids or volatile fatty acids
produced from fermentation of lipids are largely
absorbed through the rumen wall.
• Long chain fatty acid are absorbed in small
intestine.

28. Absorption of nutrient
The major organ for absorption of dietary nutrient
in monogastric animal is small intestine. Absorption
of nutrient from the lumen of intestine can be takes
place by following ways-
A. Passive transport
B. Active transport
C. Pinocytosis
A.Passive transport:
In this process involve simple diffusion process
providing a high concentration of nutrients outside
the cell passes to the lower concentration inside

29. B. Active transport:
 It is the movement of molecules across a membrane
from a region of their lower concentration to a region
of their higher concentration
 Active transport requires cellular energy (ATP or
electrochemical gradient) to achieve this movement.
C. Pinocytosis:
In which cell have capacity to capture or engulf smaller
molecule in solution or suspension.

30. Absorption of nutrients
1. Carbohydrates:
In ruminant, Most of the acid produced after
carbohydrate breakdown is absorbed directly from
rumen, reticulum and abomasum.
In non ruminant, Simple sugar are absorbed from
the intestine into the portal blood system and then
to liver in the form of glucose.

31. 2. Fat:
In ruminant,
 All short chain fatty acids or volatile fatty acids
produced from fermentation of lipids are largely
absorbed through the rumen wall.
 Long chain fatty acid, mostly saturated fatty
acid are absorbed in small intestine.
In non ruminant, Fat absorbed through intestinal
membrane in the form of fatty acids and
monoglycerides.
3. Protein: The main product of protein digestion is
amino acid and main site of absorption is small intestine.
Amino acid pass into portal blood and then into liver.

32. 4.Minerals: Mineral in the diet is absorbed across
the gastrointestinal mucosa and enter the blood.
Paracellular and transcellular mechanisms are used
by the gastrointestinal tract in absorption of
minerals.
Note: Paracellular transport is the movement of
substances across the epithelium through the intercellular
spaces between the cells. Transcellular diffusion is the
transport of molecules through both apical and basolateral
membrane

34. 5.Vitamins:
 Fat soluble vitamins are absorbed from the intestinal
lumen using the same mechanisms used for absorption of
other lipids largely by diffusion.
 Water soluble vitamins are absorbed both by simple
diffusion and by carrier-mediated transport, which is
sodium dependent for Non-ruminant.
 Vitamin synthesized by microbes are absorbed in the large
intestine or, in the case of ruminants, the rumen.

35. Thank you