Brainscape's Knowledge GenomeTM

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


See full index

Physiology III > Lecture 28: Forestomach Fermentative Digestion-2 > Flashcards

Lecture 28: Forestomach Fermentative Digestion-2 Flashcards

1
Q

Grazers or browsers: selectively feeding on highly digestible material

A

Browsers

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

What do grazers mainly eat

A

Grass

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

How do grazers and browsers handle the high concentration of tannins in their diet

A

Parotid gland produces proline-rich proteins which bind and neutralize tannins

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

Which has a larger parotid gland, browsers or grazers

A

Browsers

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

Browser or grazer: rumen content is not layered

A

Browser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the rumen structure/contents of the browser

A

No fiber mat, no stratification allowing fora more homogenous distribution of particles

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

Browser or grazer: high viscosity fluid, separation due to floatation/sedimentation less possible, gas bubbles evenly distributed

A

Browser

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

Browser or grazer: low viscosity fluid: separation due to flotation sedimentation and clear separation of gaseous layer

A

Grazer

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

What stimulates rumen papilla growth

A

VFA’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

VFA concentration is highest where __activity is highest

A

Microbial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the distribution of the ruminal papilla differ in the grazer and browser

A

Browsers have a more evenly distributed rumen papilla, whereas the papilla are greatest at the fiber mat water boundary in grazers where microbial activity and VFA’s are highest

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

Where browsers have the most papilla and greatest absorption of VFA in the dorsal, atrium or ventral rumen

A

Evenly distributed throughout all 3

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

Where are the most papilla and greatest absorption of VFA’s in the grazer rumen, dorsal, atrium or ventral rumen

A

Atrium which is boundary between fiber mat and sediment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does papilla size indicate activity in the rumen

A

Small papilla indicate decrease microbial activity and inappropriate pH, whereas large papilla indicates increase microbial activity

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

What epithelium layer are VFA’s absorbed through

A

Stratified epithelium

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

How does a long mean retention time affect utilization of fiber

A

Improves utilization of fiber

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

How does a long mean retention time affect feed intake

A

Restricts because the intake of roughage is limited mostly by the capacity of the forestomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Who has a greater mean retention time of particle passages through the rumen, browsers or grazers

A

Grazers have greater retention time for food particles through the rumen to have time for microbial fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Who has a longer fluid retention time in the rumen, grazers or browsers

A

Browsers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is it important for grazers to have a higher fluid throughput in the rumen

A

Water passing through rumen is needed to:
1. Wash out microbial proteins to SI to become available to calf (increase microbial yield)
2. Saliva contains bicarbonate buffer which will neutralize acidic rumen from VFA’s
3. Move sediment waste from the bottom that is taking up space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why is food particle throughout in rumen faster in browsers

A

Rely more on cell wall content (carbs and proteins) which is easily fermentable, unlike grazers which need to ferment fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Removing waste and microbes stimulates ___growth by maintaining appropriate conditions in the rumen. This increases ___ yield from the forestomach

A

Bacterial, microbial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Maintaining rumen activity promotes what phase of growth

A

Log phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is quorum sensing

A

Mechanism by which bacteria through small signal molecules called autoinducers regulate population density so as higher densities bacteria stop reproducing and making microbial protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 2 functions of the omasum

A
  1. Absorption of water, electrolytes, VFA and bicarbonate
  2. Transport of ingesta to abomasum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the absorption of water so important in the omasum

A

Needs to dilute solution before entering abomasum in order to optimize activity in abomasum and maintain pH2-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the function of omasal laminae

A

Surface extensions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Who has a greater water reabsorption, grazers or browsers and why

A

Grazers, because omasum is larger in size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Why does more water flow through grazers vs browsers stomachs

A

Helps remove waste and microbial protein and facilitates better fiber fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the end products of microbial production of VFA’s by breaking down cellulose and starch

A
  1. Acetate
  2. Proprionate
  3. Butyrate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the two ways in which VFA’s can be absorbed

A
  1. At pH at 6.8 VFA exist in dissociated form via the VFA/bicarb exchanger
  2. Lower pH, closer pK are absorbed via diffusion
32
Q

At what pH is VFA absorbed is dissociated form

A

6.8

33
Q

At what pH is VFA absorbed in undissociated form

A

Low pH closer to pKA

34
Q

What is the fate of acetate in the microbial production of VFA’s

A

Enter creb cycle as acetyl-CoA, form ATP and adipose tissue synthesis

35
Q

What is the fate of proprionate in the microbial production of VFA’s

A

Enter creb cycle as Succinyl-CoA resulting in gluconeogensis

36
Q

What is the main source of glucose in the ruminant and is important for milk production

A

Proprionate

37
Q

What is the fate of butyrate in the microbial production of VFA’s

A

Converted to B-hydroxybuturate and enter creb cycle as Acetyl-CoA

38
Q

How do cows help maintain pH and prevent rumen acidification

A

Saliva buffer with bicarbonate

39
Q

What type of feed generates larger amount of VFA’s in short period of time

A

Easily digestible carbohydrates like grain

40
Q

If the amount of VFA’s increase and lowers pH what microbes are favored and start producing what

A

Favored microbes producing lactic acid

41
Q

Describe the steps that can lead to rumenacidosis

A
  1. Carb overload
  2. Increase VFA’s
  3. Decrease pH
  4. Decrease lactate users(enzymes that can utilize lactate to control pH)
  5. Increase lactate producers
  6. Increase lactate
  7. PH decreases further
42
Q

Describe how an increase in VFA production can initially be beneficial but then is disadvantageous

A

1st 24hrs it will increase milk production and but then the low pH will not favor microbes that produce VFA’s but rather those that produce lactate acid and further decrease pH

43
Q

Describe how the decrease in pH increases milk production initially in rumenoacidosis

A

Initially VFA’s will go into undissociated form and will follow concentration gradient down, creating more propionate—> gluconeogenesis and increase milk production but then pH is too low to promote microbes producing VFA’s

44
Q

How can rumenacidosis cause variable appetite

A

Pain in rumen, decreased microbial activity

45
Q

How can rumenacidosis cause a drop in milk production

A

Not enough VFA’s delivered to make proprionate and undergo gluconeogenesis

46
Q

How can rumenacidosis cause diarrhea

A

Malabsorption because of the reduction of microbes

47
Q

How can rumenacidosis cause bloat

A

Decreased food intake but still producing gasses

48
Q

How does rumenacidosis increase breathing rates

A

Countermechanism to breathe off more CO2 to try and combat metabolic acidosis

49
Q

How can rumenacidosis cause laminitis

A

Metabolic acidosis and endotoxins which are fragments of bacteria that enter blood stream

50
Q

Where does glandular digestion begin

A

Abomasum

51
Q

What is the role of lysozymes in the abomasum

A

Break glycosidic bonds of bacteria wall, specifically 1,4 beta-linkages between N-acetylmuramic acid and N-acetyl D-glucosamine

52
Q

What component of the abomasum help to make use of microbial protein

A

Lysozymes

53
Q

What % of dietary protein is rumen degradable vs % bypass protein

A

Rumen degradable: 70-80%
Bypass proteins (20-30%)

54
Q

What is biological value

A

Measure for estimating how well a particular protein source is utilized

55
Q

What is considered high value protein

A

Food that contains animo acids similar to that of the host (ex: fish meal)

56
Q

What is downgrading of high biological value protein

A

Rumen degrades protein first via microorganisms and then used to resynthesizes bacterial protein that is available to animal (ex: fish meal)

57
Q

What is upgrading low biological value protein

A

Bacteria are able to use NPN to produce microbial protein

58
Q

What is the most important NPN

A

Urea

59
Q

How is urea recycle

A

Via saliva into rumen for usage by bacteria which turn it into microbial protein

60
Q

Why is adding chicken poop to diet a problem

A

Salmonella, Avian influenza

61
Q

Where is urea recycled to in ruminants

A

Large intestine and rumen via saliva

62
Q

Where is urea recycled in monogastric animals

A

SI and LI
Go ot LI for microbial digestion and go to SI just because it will eventually end up in large

63
Q

What transporters are used in urea recycling

A

Aquaporins (SI and LI)
Urea transporter B (UT-B) (LI only)

64
Q

Why is urea recycling important in hindgut fermenters

A

Salvage mechanism to improve nitrogen retention during times of protein deficits

65
Q

What determines the amount of microbial protein that reaches the small intestine

A

Amount of dietary crude protein and metabolic demand

66
Q

What determines plasma urea in a ruminant

A

Amount of microbial protein that reaches the small intestine in the presence of excess ammonia in rumen

67
Q

How can urea poisoning/ammonia toxicosis

A
  1. Rumen microbes convert NPN to ammonia via urea
  2. Ammonia is then combined with keto acids by microbes to produce amino acids
  3. If the rate of ammonia production or ingestion of ammonia exceeds microbe ability to utilize and form amino acids there is accumulation of ruminal ammonia
  4. Ammonia is normally detoxified by the liver but accumulation can overwhelm liver resulting in neurological symptoms
68
Q

What does ammonia do to ruminal pH

A

Exceeds 7.5–> alkaline indigestion

69
Q

How does accumulation of ammonia and increase pH affect ruminal contractions

A

Inhibited

70
Q

How does urea poisoning/ammonia toxicosis affect VFA,s microbial yield, milk or beef production

A

Decrease all

71
Q

Excessive intake of ____ can cause accumulation of ruminal ammonia and decrease of VFA’s

A

Crude protein

72
Q

What is a rumen drinker

A

Postnatal development of esophageal groove bypass reticulum to omasum, if this doesn’t happen then milk will spillover into rumen which is an easily digestible carbohydrate resulting in malfermentation

73
Q

What happens to the ruminal lining in rumen drinkers and why

A

Milk not shunted to abomasum and ends up in rumen will be fermented to lactic acid and decrease pH, causing inflammation, irritation and thickening of rumen which affects ability to contract and absorb nutrients (malnutrition, bloat, acidosis)

74
Q

What triggers formation of esophageal groove

A

Cephalic phase—>activation of PNS and milk let down

75
Q

How does the absence of suckling/ drinking milk out of bucket cause rumen drinking postnatally

A

Doesn’t activate PNS and cephalic phase which triggers esophageal groove

76
Q

How long do ruminants circumvent the rumen after birth

A

3 weeks

77
Q

When does a ruminant reach full adult morphology for functional fermentation

A

8 weeks

Physiology III (34 decks)

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