1
Q
What are the 4 compartments of the rumen stomach?
A
rumen, reticulum, omasum, and abomasum
2
Q
What is the acidic portion of the stomach?
A
abomasum
3
Q
What are the 3 major classes of herbivores?
A
- Concentrate selectors
- intermediate feeders
- roughage grazers
4
Q
What are some species that are concentrate selectors?
A
deer and giraffes
5
Q
What are some species that are intermediate feeders?
A
sheep, moose, goats
6
Q
What are some species that are roughage grazers?
A
cattle, buffalo, camels
7
Q
Ruminants are also considered what?
A
pre-gastric fermenters
8
Q
What are some advantages of ruminants?
A
- can eat the most abundant organic molecule (cellulose)
- can eat, run, and masticate later to get away from predators
- Detoxification of secondary plant substances
- relieves the animal of their need for B-vitamins and amino acids
9
Q
Why does a ruminant need an external source of B vitamins and amino acids?
A
Rumen microbes synthesize B vitamins and high-quality protein
10
Q
Saliva is rich in what 4 things?
A
- Na (sodium)
- K (potassium)
- HCO3- (bicarbonate
- HPO4- (phosphates)
11
Q
Why does saliva need to be rich in these things for saliva production?
A
acts as an important buffer against rumen acids
12
Q
Swallowing saliva leads to getting what?
A
VFAs
13
Q
Saliva provides how much water (in %) is in the rumen?
A
70%
14
Q
Saliva contains what for nitrogen recycling?
A
urea
15
Q
What 2 types of buffering are a function of saliva?
A
bicarbonate and phosphate buffering
16
Q
What mechanism prevents bloat?
A
saliva production
17
Q
The production of more saliva increases what?
A
increases rumination
18
Q
What is the rumination reflex?
A
postprandial regurgitation of partly digested feed from teh reticulorumen
19
Q
Ruminants chew for how long each day?
A
10-11 hours
20
Q
Why do ruminants chew so much per day (3 things)?
A
- increases surface area for microbial digestion
- breaks down waxes and other compounds on the plant surface that can’t be digested
- Stimulate saliva production for buffers
21
Q
1 glucose produces how many pyruvate and hydrogen in its hydrogen-producing reaction?
A
2 pyruvate
4 hydrogen
22
Q
1 pyruvate produces how many hydrogen in its hydrogen-producing reaction as well as which other products?
A
2 hydrogen
1 acetate
1 CO2
23
Q
What are the 3 VFAs?
A
acetate, butyrate, and propionate
24
Q
How many hydrogens are in acetate?
A
2
25
How many hydrogens are in butyrate?
4
26
How many hydrogens are in propionate?
3
27
What is eructation?
removal of fermentation gases from the rumen
Belching/burping
28
What are the 4 fermentation gases?
1. CH4
2. CO2
3. NH4
4. N2
29
What is eructation stimulated by?
distension of the reticulum and rumen
30
If failure to eructate, what does it result in?
bloat
31
What is bloat?
high-pressure buildup of gases
32
Where does bloat occur?
area behind the last rib
33
Which animal is the esophageal groove functional in?
calves
34
What are the 3 structures that increase the surface area of the rumen?
Villi, microvilli, and mucosal folds
35
What are the 5 functions of the rumen?
1. fermentation vat
2. storage
3. physical mixing and breakdown
4. contains obligate anaerobic microbes
5. absorption of VFAs
36
What are the anerobic microbes in the rumen?
bacteria, protozoa, and other microorganisms
37
What happens to the many microorganisms every day in the rumen?
gets flushed out and remade through daughter cells
38
What structure does mechanical digestion to move feed around?
rumen
39
Most of a ruminant's diet gets converted to what?
microbial waste products (VFAs)
40
How many carbohydrates reach the small intestine?
little or none
41
Where is the rumen located?
left side of the abdomen
42
The rumen is lined with?
papillae
43
What is the central intermediate of microbial fermentation?
glucose
44
The reticulum has what kind of structure?
honeycomb
45
What is the main function of the reticulum?
mixing and regurgitation
46
Digesta can pass back and forth freely from the rumen to the reticulum, which is often called what?
reticulo-rumen
47
The omasum is lined with what?
laminae
48
What does the omasum do?
reduces particle size, absorption of water and VFAs
49
The laminae lining contains what?
muscular folds
50
Absorption of VFAs in the omasum prevents what?
buffering of the abomasum
51
Which stomach compartment has no secretions?
omasum
52
Which stomach compartment is the true glandular stomach?
abomasum
53
The abomasum functions similarly to the monogastric stomach but it secretes what?
gastric lysozyme
54
What is gastric lysozyme?
enzyme that efficiently breaks down bacterial walls (microbes)
55
The abomasum holds how many gallon in the cow?
4
56
The true stomach of the ruminant contains which 3 regions?
1. cardiac
2. fundic
3. pyloric
57
The pH decreases from 6 to what in the abomasum?
6 to 2.5
58
What does decreasing the pH do in the abomasum?
denatures proteins, kills most bacteria/pathogens, dissolves minerals, and gastric digestion
59
What are the 3 digestive secretions in the abomasum?
1. HCL
2. Pepsinogen
3. Rennin (Chymosin)
60
Digestion tends to decrease with ________ ________ _________.
increasing passage rate
61
What does passage mean?
the flow (speed) of undigested residues through the digestive tract
61
What factors affect digestibility?
plant maturity, feed processing, other feeds in the diet, type of microbes
62
The rate of passage depends on what 2 things?
1. particle size
2. density
63
Passage rate will only increase by what?
increasing feed intake
64
What 3 things will increase feed intake?
1. Animal size
2. Level of production
3. Environment
65
Bacteria account for how much (in %) of the total microbial mass?
60-90%
66
Bacteria have a _____ turnover time.
rapid
67
What are the 3 bacteria in ruminants?
1. cellulolytic
2. hemicellulolytic
3. amylolytic
68
What do the cellulolytic bacteria do?
digest cellulose
69
What do the hemicellulolytic bacteria do?
digest hemicellulose
70
What do the amylolytic bacteria do?
digest starch
71
Where does the extra ATP from the bacteria go?
VFAs (acetic acid, propionic acid, and butyric acid)
72
Protozoa account for how much (in %) of total microbial mass?
20-40%
73
Protozoa are _____ in size and have a ____ turnover
large, slow
74
Lambs and calves deprived of the ruminal protozoa show what?
depressed growth rate and are "poor-doers"
75
Protozoa use the same set of substrates as what?
bacteria
76
What is thought to play a role in limiting bacterial overgrowth?
That many species consume bacteria
77
Fungi has a relatively ____ number.
low
78
Fungi can digest what?
fiber
79
Is there an exact role for fungi?
unknown
80
What is the important end product of protein and non-protein nitrogen catabolism in the rumen?
ammonia
81
What is the end product of protein fermentation?
NH3 or NH4
82
What 2 things are utilized to synthesize microbial proteins?
1. ATP
2. Nitrogen
83
What 2 things are important for amylolytic bacteria?
1. Amino acids
2. Small peptides
84
What are the 4 things that ruminants provide to the microbes?
1. Housing and heating
2. Nutrition (feed and water)
3. Buffered neutral environments
4. Waste removals
85
How does waste removal occur?
1. short chain fatty acids (VFAs) are absorbed and provide energy to the host
2. Eructation of CO2 and CH4
3. Passage of indigestible feed residue and microbes to the hindgut
86
What are the 4 things that microbes provide for the host?
1. Digestion of cellulose and hemicellulose
2. Production of VFAs
3. Detoxification of poisonous compounds
4. Supply of B and C vitamins
87
Why don't ruminants need a high protein diet?
The microbes provide a provision of high quality protein to yield 50-80% of the nitrogen required by the ruminant
88
What is the percentage of absorbed Nitrogen from microbes?
50-80%
89
Increased microbial efficiency will provide what?
more microbial protein and reduce feed costs
90
Composition of bacteria is _____ digestible.
highly
91
What are the 6 characteristics of an ideal rumen fermentation?
1. rapid rate of fiber digestion
2. optimal ratios of fermentation acids
3. efficient microbes
4. rapid microbial growth
5. slow rate of protein fermentation and minimal NH3 accumulation
6. protection from toxic substances
Nutrition
flashcards
Decks in class (15)
# Cards
-
Gastric and Intestinal Digestion (E2)88
-
CHO and Monogastrics (E2)114
-
Ruminants (E2)92
-
CHO and Ruminants40
-
Rumen Acidosis60
-
Protein Introduction82
-
Protein Digestion Monogastric74
-
Protein Digestion/Metabolism Ruminant82
-
Lipid Introduction64
-
Lipid Digestion Monogastrics (E3)75
-
Lipid Digestion Ruminants37
-
Minerals145
-
Vitamins129
-
Bioenergetics83
-
CHO Metabolism85
