Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

S + F 2 > 9. The rumen complex > Flashcards

9. The rumen complex Flashcards

1
Q

what is the purpose of fermentation?

A
  • transforms forage into the simple sugars that rumen microorganisms can use for growth
  • structural carbohydrates are broken down by rumen microbes
  • microbes ferment forages and produce volatile fatty acids which is a major energy source
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what percentage of energy can herbivores derive from microbial breakdown?

A

70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what volatile fatty acids are essential in the rumen complex?

A
  • butyrate
  • propionate
  • acetate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what re the 3 stages of rumen development?

A
  • pre- ruminant
  • transitional
  • ruminant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the oesophageal groove?

A
  • muscular structure
  • found at lower end of oesophagus
  • when closed it from a tube so milk can go directly into the abomasum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does the oesophageal groove prevent?

A

milk being fermented or soured by ruminant micro-organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how much milk replacer should calves be fed?

A

5-6 litres daily: 13-15% birth weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

when do you start feeding concentrates?

A

from 3-4 days old

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does feeding concentrates do?

A
  • increases butyrate and propionate
  • ‘digested’ in the rumen
  • increases papillae number and size (rumen absorptive ability)
  • high energy (reduces gut fill)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what problems can arise from only feeding concentrates?

A
  • hyper- keratinisation
  • clumping of papillae
  • decreased rumen motility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how long should you feed concentrates for?

A

3-4 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

why must concentrates be fed for 3-4 weeks?

A

the rumen isn’t developed enough for fibre fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the advantages of fibre?

A
  • stimulates rumination and saliva production
  • muscular development of rumen
  • increases pH
  • reduces keratinisation
  • increases DMI and size of rumen
  • improves post weaning total DMI
  • produces acetate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where is the effect on concentrates on development of papillae most noticeable?

A

Dorsal and ventral sacs of rumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how many days does it take for papillae to develop?

A

21

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

when are calves usually weaned?

A

4-8 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what percentage of hay should be fed with concentrates?

A

10%

18
Q

how many months does it take for rumen maturity?

A

4-6 months

19
Q

why feed hay pre- weaning?

A
  • promotes rumination
  • muscular growth and health of rumen
  • reduces acidosis
  • maintains rumen pH
20
Q

when is the transition period from mono gastric to ruminant?

A

over 4 weeks:
- 2 pre- weaning
- 2 post-weaning

21
Q

Why are bacteria/protozoans needed to digest fibre?

A
  • Fibre = carboyhydrate
  • Consists of glucans which are β-linked so
    can’t be digested by mammalian enzymes
  • Fermentation breaks the bonds.
22
Q

How much bacteria, protozoa and fungi can be found in the rumen?

A

Bacteria: 10 billion/ml

Protozoa: 1 million/ml

Fungi: 1000/ml

23
Q

which part of the stomach is glandular?

A

abomasum

24
Q

what shape is the abomasum?

A

j- shaped

25
Q

what side of the animal do you find the rumen?

A

left

26
Q

how does the rumen work?

A
  • Fermentation vat
  • cycle of contractions: 1-3 a minute
  • belching removes the fermentation gases
27
Q

what is the main fermentation gas?

A

methane

28
Q

how much gas is produced every hour in a cow and sheep/goat?

A

Cow: 30-50 litres/hour

Sheep/goat: 5 litres/hour

29
Q

what does the reticulum do?

A
  • traps large feed particles
  • makes sure they don’t enter next section before they are digested
  • regurgitation of ingesta
  • honeycomb structure
30
Q

what percentage of the rumen is water?

A

80%

31
Q

what is the role of the omasum?

A
  • rumen is 80% water, folds of the omasum squeeze out the water from the feed and ensures the water stays in the rumen
32
Q

what happens in the abomasum?

A
  • low pH
  • enzymes digest the proteins in the feed
  • AA’s then absorbed in small intestine
33
Q

How does a cow swallow + regurgitate its food?

A
  • Swallows fibre, rips up using tongue
  • Regurgitates and chews (to allow it to move to an area of safety)
  • ruminates until food is small enough to pass out of the rumen
  • Chewing cud = smaller particle size = more SA available to micro-organisms = efficient digestion.
34
Q

how much saliva does a cow produce?

A

150-250l

35
Q

what percentage does saliva neutralise the acid produced in the rumen?

A

30%

36
Q

what is the pH of saliva?

A

8.2

37
Q

what percentage of life do cows spend ruminating?

A

30%

38
Q

what are the food layers in the rumen?

A
  1. Layer of gas on top formed from fermentation
  2. Plant fibres (large particle size)
  3. ‘Soupy’ layer (fibre = smaller particle size)
  4. Very small fibre particles + cereals (ready to exit to omasum).
39
Q

What happens to plant carbohydrates in the rumen?

A
  • Bacteria bind to fibre + carbs broken down to smaller molecules
  • Glucose + monosaccarides released - absorbed by bacteria
  • Glycolysis releases pyruvate
  • Pyruvate is oxidised to VFAs.
40
Q

How is plant protein digested in the rumen?

A
  • bacteria bind to fibre - plant cell was and the protein Is broken down to small peptides
  • broken down to Amino acids which is used by bacteria. Most deaminated to ammonia and VFA
  • ammoni and VFA used to make bacterial protein
  • bacteria pass into small intestine, protein digestion provides amino acids for the cow
41
Q

what does rumen degradable protein (RDP) do?

A
  • feeds rumen bacteria
  • ensures adequate supply of microbial protein
42
Q

what does rumen undegradable protein (RUDP) do?

A
  • passes through the rumen unchanged
  • digested in small intestine

S + F 2 (30 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions