Lecture 55- Ruminant Digestive Physiology 2

Question 1

How does milk bypass the rumen at birth?

Answer 1

Esophageal groove

Question 2

What is the makeup of the rumen at birth?

Answer 2

Rumen is the same size as the abomasum
No microbes
Thin wall with short papillae and undeveloped pillars

Question 3

What is the make up of the rumen by 3 weeks?

Answer 3

-calves start to ingest forage and concentrate (grain)
-microbes start to establish (cow licks the calf, pick up microbes from environment)
-rumen enlarges (mucosa transforms, papillae grow)

Question 4

What is formation of the esophageal groove stimulated by?

Answer 4

Chemical (milk)
ADH
Suckling

Question 5

Why is the esophageal groove important in bypassing forestomachs?

Answer 5

Milk is poorly digested in rumen

Question 6

What is the anatomical structure of newborn/young calf’s esophageal groove?

Answer 6

Esophageal groove connects the cardia region to omasum

Pharyngeal afferent neuronal pathways

Question 7

What gas does rumen fermentation produce?

Answer 7

65% CO2
25% CH4
7% N

Question 8

What are the major gases that the rumen releases?

Answer 8

CO2 and CH4

Question 9

What are the 5 F’s of abdominal distension?

Answer 9

Fart
Fluid
Flood
Fetus
Fat

Question 10

What are the four different types of varieties indigestion syndrome?

Answer 10

Type 1: free gas bloat/failure to eructate
Type 2: failure of transport out of rumen
Type 3: failure of transport out of abomasum
Type 4: Indigestion associated with advanced pregnancy

Question 11

What is vagal indigestion syndrome?

Answer 11

Gradual development of abdominal distinction secondary to rumenoreticular distinction

(Diseases resulting in injury, inflammation, or pressure on vagus nerve -> signs of vagal indigestion)

Question 12

What is free gas bloat (secondary ruminanal tympany) cause?

Answer 12

Esophageal obstruction (Choke)
Interference in nerve pathways involved in education
Grain overload leading to esophagitis and rumen it is
Interfering with eructation

Question 13

What is the treatment for free gas bloat?

Answer 13

Stomach tube to relieve gas pockets

Question 14

What is the definition of bloat (ruminants tympany) ?

Answer 14

Overdistension of the rumenoreticulum with gases of fermentation

Question 15

What is frothy bloat (primary ruminants tympany) ?

Answer 15

Frothy—foam mixed with ruminal contents

Froth gets up against cardia region + eruction cant occur b/c gas accumulation bubbles
Gas pressure increases and put pressure on diaphragm

Question 16

What are three contributing factors to frothy bloat?

Answer 16

1. High legume diets
2. Feedlot cattle (fine particle size of diet can allow bubbles to form)
3. High-risk pastures

Question 17

What is hardware disease?

Answer 17

Cows are indiscriminate eaters
Heavy material/foreign objects fall into reticulum during primary rumen contractions

Question 18

What are two contributing factors to a displaced abomasum?

Answer 18

1. Hypomotility
2. Peripatetic to changes in location of intra-abdominal organs

Question 19

Where is the abomasum located?

Answer 19

Suspended loosely by greater and lesser momentum in right front quadrant of abdomen

Question 20

What does a right displaced abdomen lead to ?

Answer 20

Volvulus and ischemia

Question 21

How does hypomotiilty contribute to a displaced abomasum?

Answer 21

High grain diet, less motility, gas flows into abomasum

If rumen mat is absent -> rumen contractions slow/stop -> abomasum contractions slow/stop -> allows gas to build up, abomasum lifts and displaces

Question 22

What is rumen pH determined by?

Answer 22

-intake of fermentable carbohydrates
-buffering capacity of rumen
-rate of VFA absorption

Question 23

What are the steps to development of SARA?

Answer 23

1. Shortage of amylolytic bacteria allows S. Bo is to grow and produce lactic acid
2. Lactic acid builds up, pH drops
3. Clinical signs not as severe, but feed intake decreases and milk production stops

Question 24

What is subacute rumen acidosis (SARA)?

Answer 24

PH drops not as severe and due to overall accumulation of VFA
Lactic acid production starts and will accumulate

Question 25

At what pH does acute acidosis occur?

Answer 25

<5.5

Question 26

What is acute acidosis?

Answer 26

Lactic acid accumulation
PH depression extreme
Some lactic acid absorption into blood

*VFA absorption is impaired and bacteria invade rumen wall

Question 27

What is the treatment/prevention for SARA and acidosis?

Answer 27

Feed ionospheres (inhibit lactic-acid producing bacteria), buffers, lactic-acid utilizing bacteria