Ruminant GI Tract

Question 0

Orientation of Stomach Compartments

Answer 0

Left side: Rumen, reticulum

Right side: Omasum, abomasum

Question 1

How many permanent upper incisors does a 3 year old ewe have?

Answer 1

None. All ruminants have 0 because they have a dental pad.

Question 2

Which side is a cannula always placed on and why?

Answer 2

Left. That’s where the rumen is.

Question 3

What is secreted into the rumen?

Answer 3

Nothing.

Question 4

Definition of Fermentation

Answer 4

Anaerobic digestion of feed material

Question 5

The three types of microbes that live in the rumen

Answer 5

Bacteria, Fungi, Protozoa

Question 6

Which animal enzymes can digest fiber?

Answer 6

None. This is why bacteria especially are needed.

Question 7

What is the main source of energy for ruminants?

Answer 7

VFAs–the microbial waste products.

Question 8

Which microbe is primarily responsible for digesting the ruminant’s dietary fiber?

Answer 8

Bacteria

Question 9

Characteristics of VFAs

Answer 9

Smell bad, soluble in water, volatilized easily.

Question 10

Where do VFAs go once they are absorbed through the rumen wall?

Answer 10

Enter the portal vein and go to the liver.

Question 11

What nutrients are absorbed through the rumen wall?

Answer 11

Only VFAs and water.

Question 12

How many bacteria are in the rumen (per mL of rumen fluid)?

Answer 12

10 billion

Question 13

How many protozoa are in the rumen (per mL of rumen fluid)?

Answer 13

100,000

Question 14

How do fungi aid in feed digestion?

Answer 14

They grow “roots” that help break food particles apart.

Question 15

Types of Rumen Bacteria

Answer 15

Hundreds and hundreds. The predominant type present will depend on what the animal is eating (grain vs. forage).

Question 16

What are you really feeding when you feed ruminants?

Answer 16

The microbes

Question 17

What pH level bothers the fiber-digesting bacteria?

Answer 17

Drops in pH below 6.0

Question 18

Where can the bacteria be located in the rumen?

Answer 18

Free-floating, feed adherent, or along the edge of the rumen wall.

Question 19

How much of the ruminal bacteria is feed adherent?

Answer 19

3/4 of it.

Question 20

What do feed adherent bacteria commonly digest?

Answer 20

Fibrous feeds

Question 21

What do free-floating bacteria commonly digest?

Answer 21

Starch and other soluble substrates.

Question 22

What types of bacteria live along the edge of the rumen wall?

Answer 22

Facultative.

Question 23

Characteristics of Facultative Bacteria

Answer 23

They CAN use oxygen. They have urease activity–they break amino groups off urea to make microbial protein.

Question 24

When does VFA build-up in the rumen occur?

Answer 24

Never since the VFAs are constantly absorbed through the rumen wall.

Question 25

The Three VFAs and the Number of Carbons in Each

Answer 25

Acetate (3 carbons), Propionate (2 carbons), and Butyrate (4 carbons)

Question 26

Predominant VFAs on a High Forage Diet

Answer 26

70% acetate 20% propionate 7% butyrate

Question 27

Predominant VFAs on High Concentrate Diet

Answer 27

55% acetate 35% propionate 7% butyrate *Have same amount of acetate as on high forage diet but have more propionate also which makes total amount of VFAs higher on a largely grain diet because the grain is so fermentable

Question 28

Gases Produced During Fermentation

Answer 28

CO2 and CH4

Question 29

How are the gases produced during fermenation gotten rid of and why can it be a good and bad thing?

Answer 29

Eructation. Losing carbons means losing energy. Losing hydrogen is good because it prevents the pH from getting too low.

Question 30

What can the animal do with the VFAs?

Answer 30

Propionate: the liver converts it to glucose then sends it to tissues for use Acetate: Goes directly to tissues for use, muscle uses it for main energy source Butyrate: ... it's not glucogenic

Question 31

What bacteria provide to the ruminant animal?

Answer 31

VFAs for energy, vitamins (all B vitamins), high quality protein.

Question 32

What happens to the ruminal pH after the sheep/goat eats a meal?

Answer 32

The pH drops.

Question 33

What pH inhibits fiber-digesting bacteria?

Answer 33

pH below 6

Question 34

What are amylolytic bacteria and what pH are they sensitive to?

Answer 34

Starch-digesting bacteria, more sensitive to higher pHs, not inhibited by the lower pH of eating a meal.

Question 35

What enzyme is secreted in the abomasum?

Answer 35

Pepsin

Question 36

What happens in the abomasum?

Answer 36

Microbes are killed because of the low pH because of hydrochloric acid and they start to get digested with the animal's feed.

Question 37

What enzymes are secreted in the small intestine and which ones are important?

Answer 37

Pancreatic lipase, pancreatic amylase, and pancreatic proteases. Only the proteases are really needed. Dietary protein and microbial protein must be broken down in the small intestine.

Question 38

What part of fat digestion/absorption takes place in the small intestine?

Answer 38

Fat is digested in the rumen and individual fatty acids are absorbed in the small intestine.

Question 39

How can fatty acids be broken apart?

Answer 39

Oxidation

Question 40

How are newborn ruminants considered according to their GI tract?

Answer 40

They are more like monogastrics since their rumen is not functioning.

Question 41

How long does it take for the rumen to develop?

Answer 41

6 weeks

Question 42

What stimulates ruminoreticulum development?

Answer 42

Eating fiber. The scratching of the solid feed stimulates the muscle contractions of the ruminoreticulum.

Question 43

What causes the papillae to grow?

Answer 43

VFAs

Question 44

What is another name for the reticular groove? What is the function of the reticular groove?

Answer 44

Esophageal groove. Milk bypasses the rumen via this groove and goes straight to abomasum to avoid being fermented in the rumen.

Question 45

How are nutrient requirements determined?

Answer 45

They are based on the intended purpose of the animal--->their production.

Question 46

What have dairy goats been genetically selected for? How are dairy goats fed?

Answer 46

High milk production and we feed them similar to dairy cows.

Question 47

What type of goats have lower nutrient requirements and why?

Answer 47

Brush/Spanish goats because they have fewer offspring and produce less milk.