Rumen Anatomy

Question 1

What are the 5 major functions of the ruminant digestive system?

Answer 1

1. Ingestion
2. Chewing (mastication and ensalivation)
3. Swallowing (deglutination)
4. absorption of nutrients
5. elimination of solid waste (defecation)

Question 2

What is the function of salivary glands and saliva?

Answer 2

1. some enzymes (like pre-gastric esterase in young)
2. buffer secretion
3. moisten and lubricate feed
4. recycling of N and minerals
5. Water balance
6. bloat prevention

Question 3

What factors affect salivary secretion?

Answer 3

1. dietary fiber concentration
2. diet particle size
3. diet moisture level

Question 4

What is the esophageal groove and what is its purpose?

Answer 4

channel between esophageal opening and reticulo-omasal orifice

lets milk bypass rumen when it closes

Question 5

Structures of rumen

Answer 5

Made of 5 sacs
a. cranial sac
b. ventral sac
c. ventral caudal blind sac
d. dorsal caudal blind sac
e. dorsal sac

Question 6

Structures of reticulum

Answer 6

a. cardia valve connects it to esophagus
b. reticulo-omasal orifice connects it to rumen
c. esophageal groove connects esophagus to reticulo-omasal orifice

Question 7

What is the purpose of the honeycomb lining of the reticulum?

Answer 7

sieve out large particles for mastication

small particles that collect in honeycombs are pushed into reticulo-omasum orifice

Question 8

Does the animal secrete digestive enzymes into the rumen and reticulum?

Answer 8

no digestive enzymes into the rumen

Question 9

What is hardware disease?

Answer 9

heavy objects trapped in the reticulum has the potential to pierce the heart

Question 10

What is the purpose of rumen papillae?

Answer 10

increase surface area for greater absorption of nutrients

Question 11

What damages rumen papillae and what can result from that damage?

Answer 11

excessive acid production or lack of physical scratching can lead to irregular growth, damage, and inflammation (parakeratosis)

Question 12

If bacteria and toxins cross rumen wall it can cause ________________

Answer 12

liver abscess

Question 13

What are 2 ways that coarse particles are prevented from entering the omasum?

Answer 13

claws and ROO

Question 14

How is flow from the reticulum to the omasum controlled?

Answer 14

it is controlled by reticlo-omasal orifice. Digesta movement is associated with rumen contractions

Question 15

What are the 5 major events involved in digestive motility?

Answer 15

1. Regurgitation
2. Re-mastication, re-ensalivation
3. Deglutition (swallow)
4. Eructation
5. Contracts of rumen and GIT

Question 16

Why do ruminants ruminate?

Answer 16

predator theory: hide to avoid predators
particle size reduction: break impervious coating of plant material

Question 17

When do animals ruminate?

Answer 17

when the animal is resting

Question 18

What causes bloat?

Answer 18

failure to eructate

Question 19

Types of bloast

Answer 19

1. Ruminal (Foamy or Free gas)
2. Abomasal