DIFFERING DIGESTIVE
TRACTS
Proper nutrition of animals requires knowledge of the
digestive system, basic nutrients, and the ways in which
foods are formulated and marketed.
–Proper feeding and nutrition can prevent many health
problems and diseases.
-Good nutrition is especially important for pregnant
animals and animals recovering from surgery or illness.
- Understanding the different types of systems helps you
understand how to properly take care of the different
animals (what to feed them, how much, how often, ect)
TYPES OF TRACTS- RUMEN
Ruminants have four compartments to their stomach.
1. Rumen – “The Fermentation Vat”
a. Largest compartment
b. Makes up approximately 80% of the stomach’s
capacity
c. Contains millions of bacteria and
microorganisms that partially break down food
d. Bacteria and microorganisms transform lowquality protein and nitrogen compounds into
essential amino acids.
e. Food is regurgitated from the rumen,
rechewed in the form of a cud, and reswallowed
for further digestion.
2. Reticulum - “ The Honeycomb”
a. Inner walls are lined with membranes that are
divided into honeycomb-like compartments.
b. Foreign matter such as nails and wires is
filtered by the reticulum.- collects metal
THE OTHER TWO PARTS…
3. Omasum – “Manyplies”
a. Contains many folds
of tissue that line the
interior.
b. Absorbs water and
decreases the size of food
particles.
4. Abomasum – “True Stomach”
a. Secretes digestive
enzymes.
b. Functions similar to the
stomach of a nonruminant.
c. Functions as digestive
unit of calves until several
months old when
rumination begins.
Nonruminants
1. Food is passed from the mouth to the
esophagus to a single compartment stomach.
2. The stomach breaks down food by muscular
movement and digestive juices.
3. Digestive juices break down proteins and fats.
4. The primary site for digestion and absorption of
carbohydrates, lipids, and proteins is the small
intestine.
5. Undigested food passes from the small
intestine to the large intestine where water is
absorbed and lubricating mucus is added to aid
the passage of material through the large
intestine.
CECAL FERMENTERS
1. Horses, guinea pigs and rabbits are examples
of cecal fermenters. They have a large cecum
allowing them to consume moderate levels of
roughages.
2. Bacteria are present in the cecum to digest
roughages.
3. ALL other animals have a cecum but don’t use them
The Digestive Process:
1. Digestion is the process by which food particles are
broken down into nutrients. The five processes
involved in digestion are:
a) Mechanical digestion begins in the mouth
where food is chewed and broken down into
smaller pieces. Poultry have no teeth but use a
gizzard to grind and break down food. A
gizzard is a muscular structure of the
esophagus that contains grit.
b) Peristalsis is a muscular contraction of the
digestive system that causes food to move
through the digestive tract. Peristalsis occurs
as a wavelike movement.
Digestive Process
1. Digestion is the process by which food particles are broken down into
nutrients. The five processes involved in digestion are:
1. Mechanical digestion begins in the mouth
where food is chewed and broken down into
smaller pieces. Poultry have no teeth but use a
gizzard to grind and break down food. A gizzard is a muscular structure
of the esophagus that contains grit.
2. Peristalsis is a muscular contraction of the
digestive system that causes food to move
through the digestive tract. Peristalsis occurs
as a wavelike movement.
3. Chemical digestion involves enzymes and
acids to reduce food particle size and change
food particles into forms that the animal can
use. Some chemical digestion occurs in the
mouth with saliva, but most chemical digestion
take place in the stomach and small intestines.
THE PROCESS….
4. Absorption is the process by which nutrients move from the digestive tract into
the bloodstream. It takes place mainly in small intestine through villi (microscopic
structures that line the walls of the SI). In ruminants,some absorption takes place in
the rumen. Absorption occurs through the processes of diffusion and osmosis.
Nutrients diffuse (or move) from an area of high concentration to an area of low
concentration – IE from the digestive
tract to the bloodstream.
5. Metabolism is the process that removes nutrients from the bloodstream and
allows different organs of the body to use nutrients. Metabolism is responsible for
growth of bone, muscle, fat, skin and hair. It maintains body temperature and
proper functioning of organs. It also aids in repair of body tissue, production of milk
and young, and performance (work, sexual).
Nutrition:
Nutrition is receiving a proper and balanced food and
water ration so that the animal can grow, maintain its
body, reproduce, and produce.
Nutrients
Nutrients are substances or ingredients that are part of
the diet of an animal that help maintain good health
and promote growth.
a. Proteins
b. Carbohydrates
c. Fats
d. Minerals

The Feed Label:

The label on a bag of animal feed is packed with useful

and often misleading information. The trick is to be

able to read between the lines. To do that you must

know what to look for on any feed label.

The AAFCO (American Association of Feed Control

Officials) is an agency that develops and maintains

standards of uniformity for all aspects of animal feed

production and sales. They dictate what information

must be provided on the feed label.

Parts of the Feed Label

1. Manufacturer’s name

2. The name of the product

3. Phone number/address where manufacturer can

be contacted

4. Net weight of the product

5. Guaranteed analysis

Must contain the minimum percentage of

crude protein and crude fat, and the maximum

percentage of crude fiber and moisture.

6. Ingredient panel

Ingredients are listed in order from the

ingredient that is most abundant by weight to

the least abundant by weight.

7. Nutritional claim

• It is based on the idea that one food is

adequate for all stages of the animal’s life

• Scientific evidence shows that an animal’s

nutritional needs change during various

stages of life; therefore it is likely that the

nutritional claims are false. Foods could be

exceeding the required amounts of some

nutrients according to the AAFCO

(Association of American Feed Control

Officials) standards.

3. Price

• Can be very misleading.

• The best way to evaluate the cost is to

conduct a cost per feeding analysis.

• You get what you pay for! Low price

usually equals low quality!

4. Palatability

• Palatability is the primary characteristic by

which most animal owners judge a food.

• It does not relate to nutritional value.

• Gimmicks like “let the pet decide” are used

to induce a consumer to purchase a particular

food.

• Palatability Factors

a. Odor

b. People food
2. Calculating Dry Matter of a Feed
• Animal feeds can be dry, semi-moist, or
moist.
• Base your comparison of nutritional
content of two or more foods on dry
matter content.
• %Dry Matter =
(%Nutrient) / (100% Moisture) x 100
• Obtain a dry matter analysis from the
manufacturer since this information is not
required to be printed on the label.
• Converting nutrients to dry matter allows
for a more accurate comparison of feeds.
3. Maintenance Energy Requirements (MER)
• Knowing how much to feed an animal is
just as important as knowing what foods
are available and their quality.
• Nutrient requirements vary with age,
activity, production, reproduction and
environmental conditions.
• Maintenance energy is determined in
kilocalories per day (Kcal/day). A
kilocalorie is the caloric measurement
used for metabolic studies. It is the
amount of heat required to raise the
temperature of one kilogram of water one
degree Celsius. This is what people refer
to as a “calorie” when they discuss diet
and exercise.
• Maintenance energy requirements can
easily be calculated, but may need to be
adjusted based on the individual animal’s
lifestyle and body condition.