Exam 2 Flashcards
1
Q
roles of the large intestine
A
- microbial fermentation
- absorption
- expels waste
2
Q
define hindgut microbial fermentation
A
microbes fermenting “leftovers”, what the animal could not absorb itself (mostly fibers)
3
Q
What does the large intestine absorb?
A
main: VFAs
and water (electrolytes - macro minerals)
4
Q
What are crypts in the large intestine?
A
stem cells
5
Q
define feces
A
expelled in waste, what can’t be digested/absorbed
6
Q
define endogenous losses
A
expelled in waste, sloughed cells (dead epithelium, bile, enzymes, etc.)
7
Q
immune functions of the large intestine
A
motility, flushing it out
8
Q
What are the structural parts of the large intestine?
A
- mucosal tissue
- cecum
- large colon
- small colon
- rectum
9
Q
structure of the cecum
A
a “blind sac”, goes to no where, lots of fermentation
10
Q
What is the structure of the large colon?
A
leads to the rectum
11
Q
What is the structure of the small colon?
A
spiral
12
Q
What is the structure and function of the rectum?
A
- highly controlled sphincter
- nervous regulation
13
Q
What is the relationship between feces and water absorption?
A
the more water absorbed in the intestine, the harder and smaller the poop
14
Q
Why does the large intestine have lower surface area than the small intestine?
A
there are no vili in the large intestine, so there is a lower surface area
15
Q
Where is the pancreas located?
A
between the stomach and small intestine
16
Q
What is the function of the pancreas?
A
synthesize and secrete digestive enzymes (80-90% - exocrine) and metabolic hormones (5-20% - endocrine) and secretes bicarbonate into the small intestine
17
Q
What is the function of the digestive enzymes?
A
the pancreas secretes them in the duodenum into the gi tract (acts before small intestine enzymes)
- examples: proteases, lipases, amylases
18
Q
What is the function of metabolic hormones?
A
some regulate the gi tract, others metabolism
- example: insulin
19
Q
What is the function of bicarbonate in the small intestine?
A
- buffer (HCl)
- elevate the ph closer to 7 (neutral)
20
Q
What is the function of the liver?
A
- bile
- metabolism
- storage of some vitamins and minerals
- short term energy storage (glycogen)
- detoxification
21
Q
Where is bile stored?
A
gallbladder, unless the animal does not have one then it is stored in the liver
22
Q
What is the function of bile?
A
fat emulsification
23
Q
What is the function of detoxification in the liver?
A
metabolizing “non-nutrients”
–> hormones, alcohol, drugs
24
Q
What is the function of a gallbladder?
A
- found on the liver
- stores and releases in bile
(not present in all species)
25
What is the function of the kidneys?
not attached to gi tract, no direct secretion, but handles things the gi tract brings in
- detoxification (urea)
- excretion of waste (urine)
- water balance (electrolytes)
26
What is the function of the brain in the gi tract?
regulates the gi tract because it controls the nervous system
- highly involved in satiety
- produces metabolic and gi hormones
- target of hormones
27
define satiety
fullness, stop eating
28
define fermentation
microbial metabolism of organic compounds to obtain energy in and anaerobic environment
29
What are microbes?
bacteria (most) and Protozoa (largest in size)
30
What organic compounds are being fermented?
- carbohydrates
- carbon skeletons of AA
- glycerol backbones of triglycerides
31
What are the products of fermentation?
- ATP (for the microbes)
- coproducts (good=VFA, bad=CO2, CH4)
32
Where is fermentation located in a ruminant?
rumen, reticulum, omasum (and large intestine)
33
What are the 4 steps in the ruminant gi tract?
1. RRO (fermentation) --> complex foregut
2. gastric stomach
3. small intestine
4. large intestine
34
What is the importance of fermentation happening before the animal does digestion and absorption?
1. gives microbes a first chance to ferment nutrients
2. microbes from RRO are food (protein) for the animal
35
How are microbes killed?
HCl, they pass out/die and go into the stomach
36
Why is feeding a ruminant more complicated than feeding a monogastric?
feeding the microbes first and hoping we can get the nutrients to the animal
37
define coprophagy.
eating feces
38
define regurgitation.
throwing up, before rumination
39
deine rumination.
rechewing previously consumed feed (mostly fibers and long pieces of forage)
40
Why do ruminants ruminate?
to decrease particle size, increase surface area, and increase digestion
41
define eructation.
rid of gases, belch (prevent bloat)
42
define bloat and how it can become an issue
accumulation of gas, if an animal gets bloated they can suffocate and die
43
Where is most of the digesta located?
| ruminant
in the 4 stomach sections?
44
Does a ruminants stomach have a slow or fast passage rate?
slow passage rate
45
What is the order of the sections of the stomach complex?
1. reticulo-rumen
2. omasum
3. abomasum (gastric stomach
46
What are the layers of the stomach complex?
TOP - gas cap (CH4, CO2)
- fiber mat
- liquid (microbes and small feed particles)
BOTTOM - heavy material (rocks, metal, etc)
47
What is the fiber mat in the stomach complex?
fiber floats on top of the stomach liquid, makes it easier to regurg into the esophagus
48
What is the function of the pillar structures in the stomach complex?
promotes good mixing of the rumen and sections the stomach complex
49
Why are the reticulum and rumen called the reticulo-rumen?
the rumen and reticulum are continuous
50
What are the functions of the reticulo-rumen?
- main site of microbial fermentation
- house microbes
- absorption of VFAs and ammonia
51
Where is the main site of microbial fermentation?
| ruminant
reticulo-rumen
52
What makes the environment of the reticulo-rumen ideal for microbial fermentation?
- lots of water
- warm (102-108 degrees F)
- ph is variable
- no oxygen
53
Why is there a honeycomb structure in the reticulo-rumen?
we don't know why
54
How do we study microbes?
microbes are difficult to study because it is hard to simulate or enter their exact environment. However, now we can genotype them.
55
What are papillae?
structures in the reticulo-rumen that increase surface area and give microbes a home
56
Why would papillae change shape/size?
- top of the rumen has loose bumps (less absorption)
- mid-bottom of rumen have massive papillae because they are absorbing lots of nutrients
- diet: more fermentation=large papillae, not eating=small papillae
57
Is the rumen motile?
the rumen is very thick and muscular and constantly moving
58
describe the rumen epithelium
- covered in papillae
- NOT mucosal
59
What is the structure of the omasum?
it is a hard structure with NO papillae, but LOTS of nubs/folded tissue
60
What is the function of the omasum?
- controls passage to abomasum
- absorption of VFAs and NH3 (not yet absorbed)
61
Why does the omasum have so many folds?
to increase surface area, to increase absorption
62
What is the structure of the tissue in the abomasum?
it is mucosal
63
Which part of the stomach complex gets a continuous digesta flow?
abomasum
64
In a ruminant, what parts of the gi tract are similar to a monogastric?
- small intestine
- large intestine
65
Why would the stomach complex shrink?
if there is less nutrients coming in
- (passage rate will also decrease)
66
What are the microbe types named after?
what they do or break down
67
What are the goals of a microbe?
- survive
- grow
- reproduce
all of these use energy!! growth and reproduction uses AA and FA.
68
What are microbes made up of?
protein and fats
69
Where do microbes get their ATP from?
carbon skeletons, carbohydrates, and glycerol backbones
70
What carbohydrates can microbes degrade with enzymes?
- fiber
- starch
- sugar
71
Which type of carbohydrate do fibrolytic microbes degrade that have beta linkages?
fiber
72
Which type of carbohydrate do amyolitic microbes degrade that have alpha linkages?
starch
73
What is the main product of microbial fermentation of monosaccharides?
ATP
74
What are the coproducts of microbial fermentation of monosaccharides?
- VFAs
- CO2
- CH4
75
What is the structure of a VFA?
short chained fatty acid (2-8 chains)
76
What is a VFA?
- Volatile Fatty Acid
- not needed by microbes but can be used by the animal in glucogenoisis (for energy)
77
Are VFAs soluble in water?
YES, although they are fatty acids they have short chains
78
Is the ph of VFAs low or high?
low, they are acidic
79
Where are VFAs absorbed?
in the RRO epithelium (and large intestine)
80
If a ruminant is eating more starch, would it have a high or low ph?
LOW PH (5.5-6.5) because more VFAs are being produced and there is a quick rate of absorption
81
What are common VFAs?
- butyrate
- acetate
- propionate
82
If a ruminant is eating more fiber what is their ph?
NEUTRAL because fibers are more neutral materials
83
When changing an animals diet, why does it need to be done slowly?
the microbes need time to adapt (when there are less substrates for a type of microbes they will regress, so you need to introduce the new diet slowly to let the microbe population build back up)
84
What is the speed of fiber fermentation?
slower, fibers are harder to break down (chew, metabolize, lignin)
85
Where are fibers broken down if they escape the RRO?
fermented in the large intestine
86
What microbes and enzyme(s) break down fibers?
- fibrolytic
- cellulose
87
What microbes and enzymes break down sugars and starches?
- amyolytic
- amylase, sucrase, lactase
(can be used WITHOUT microbes)
88
What is the speed of starch/sugar fermentation?
faster, VFAs are produced rapidly
89
What is sub acute acidosis?
an animal has very low ph, caused by feeding too many starches/sugars
90
Where are starches/sugars digested if they bypass RRO?
small intestine and absorbed
(does not happen often)
91
What lipids do microbes hydrolyze?
triglycerides and phospholipids (to yield glycerol and FA)
92
What is yielded when microbes break down lipids?
fatty acids and glycerol (12-20 chained)
93
What is the product of fermenting a glycerol backbone from a triglyceride?
VFA
94
Can microbes break down fatty acids?
NO
95
3 things microbes can do to a fatty acid:
- biohydrogenate
- isomerize
- incorporated into the microbe (growth and reproduction)
96
define biohydrogenation
fats are saturated
(hydrogens are added changing all double bonds to single bonds)
97
define isomerize
changing the location of the double bonds
98
What are proteins?
strings of amino acids that fold
99
What enzymes to microbes use to break down proteins?
- proteases and peptidases
- deaminase
100
function of proteases and peptidases
enzymes that release AA and peptides
101
function of deaminase
enzyme that pulls off ammonia (NH3), leaving the rest of the amino acid (c-skeleton)
102
3 different groups of microbe likes:
1. AA, small peptides
2. NH3, (make AA themselves)
3. AA and NH3
103
What determines what a microbe likes?
dependent on what enzymes they have
104
define "microbe commune"
microbes work together, not every microbe is doing every job and every process, they share
105
3 things microbes do to amino acids
1. microbial protein synthesis (MCP) -- (priority)
2. catabolized (deaminated)
3. reamination/AA synthesis
106
define microbial protein synthesis
microbes change the AA to what they need
--> priority because it is used for growth and reproduction
- make microbial crude protein (MCP)
107
define deaminated
remove NH3 and leave c-skeleton
- NH3 used for AA synthesis
- c-skeleton is fermented
108
define reamination/AA synthesis
take NH3, add c-skeleton to produce an AA
109
What are deamination and reamination used for?
changing the AA profile
1. change AA profile to what they want/need
2. make AA from scratch
110
Can animals synthesize amino acids?
NO
111
Why is it useful that microbes can change the AA profile?
microbes can make AA profiles that are more similar to the animal making them more useful
--> turning urea and NPN to useless to useful
112
Where are proteins digested if they escape the rumen?
digested and absorbed in the small intestine
113
define NPN
Non-protein Nitrogen
--> something that is no an AA
114
What is the only part of a protein that is being fermented?
c-skeleton
115
define MCP
Microbial Crude Protein
--> animals can use MCP and absorb it as a protein (HCl kills the microbe and pepsin breaks it down and digests it, yield is more similar to an animal profile)
116
define bypass
if a feed particle escapes the RRO
117
What determines if a feed particle gets fermented or not (in the RRO)?
1. microbes are unable to degrade the particle
2. microbes don't have enough time to degrade the particle
118
What are some reasons microbes may be unable to degrade a particle?
- don't have the enzyme
- extra protection on the feed particle
119
define a rumen protected feedstuff
humans were able to change the nutrient to protect it from the microbes so that the animal gets the nutrients from it
120
What are we feeding rumen microbes?
- soluble carbs --> ATP
- RDP (ruminally degradable protein) --> AA + NH3
- NPN (non-protein nitrogen) --> NH3
- fatty acids --> grow and reproduce
121
What are we feeding the ruminant (abomasum and small intestine)?
- leftover feed
- microbes
- microbial products (VFAs)
122
What "leftover feed" is the ruminant fed?
- any starch or sugar that escapes the rumen
- RUP (ruminally undegradable proteins)
- lipids --> modified by microbes
123
define RDP
Ruminally Digested Protein
--> microbes can digest it
124
define RUP
Ruminally Undegradable Proteins
--> microbes cannot use/break down
125
What nutrients does the ruminant get from digesting the microbes themselves?
- MCP (microbial crude protein --> 80% CP)
- lipids
- VFAs
- NH3
126
Why do ruminants have a low blood glucose?
they rely on VFAs as an energy source
--> (VFAs make glucose)
127
What is a nutrient requirement according to the NRC/NASEM?
average for a group of similar animals based on physiological state
128
What is a nutrient requirement measured in?
amount/day
- kcal ME/d
- lb CP/d
129
Can an energy requirement be a percent?
NEVER use % or other concentration (mcal/kg)
130
For a population of animals, if they require less nutrients are they more or less efficient?
MORE efficient
131
For a population of animals, if they require more nutrients are they more or less efficient?
LESS efficient
132
Why do we feed the mean requirements to a population of animals?
average requirements will get you close to good efficiency
133
What does "individual differences in efficiency of nutrient nutrient utilization" mean?
all animals are unique in how they use nutrients
134
What affects overall nutrient requirement?
species, breed, sex, age, BW, physiological state, genetics, physical work, other production, body composition, health, previous nutrition, season, environment, individual differences
135
define deficiency
where there is too little of the nutrient/energy consumed and it results in lower animal performance
136
What are some effects of deficiency?
- lose weight
- slower growth and production
- negative physiological consequence (vitamin and mineral deficiency)
137
For what nutrients can you be deficient?
ALL nutrients
138
define toxicity
caused by too much nutrients/energy consumed causing a decrease in animal performance
139
What are some effects of toxicity?
- low growth and production
- decrease body weight (less likely)
- negative physiological consequence (copper or selenium toxicity)
140
What nutrients can be toxic?
NOT ALL nutrients (but many)
- difficult to get toxicity from micronutrients
- water soluble vitamins are easily removed through urine
141
If an animal is deficient, and you give it slightly more of the nutrient it is deficient in, would it be a greater increase or minimal increase in performance?
greater increase in performance
142
If an animal is in optimal performance range of nutrient input, and you give it slightly more of an input, would it be a greater increase or minimal increase in performance?
minimal increase in performance
143
define excess in nutrition
there is no change in performance, but nothing bad is happening to the animal
144
Why are livestock sometimes fed excess nutrients?
- intake for nutrient variation
- ingredients may be low in cost, high in nutrients
- ensure performance
145
What are some issues with excess?
- not as efficient (greater input, no change in output)
- close to toxicity amounts
146
What does NRC stand for?
National Research Council
147
What does NASEM stand for?
National Academy of Science, Engineering, and Math
148
What does the NRC and NASEM do?
they are a committee of scientists that author publications and define nutrient requirements based on research
149
How often do they publish nutrient requirements per species?
every 10-20 years
150
Why are nutrient requirements for poultry and swine not published as often?
often, poultry and swine companies use their own research and nutrient requirements based on the specific genetics their animals have
151
What protein nutrient requirements do we use for ruminants?
- metabolizable protein (MCP and RUP) or CP
--> protein delivered to small intestine
- RDP
- some AA
152
What protein nutrient requirements do we use for swine and poultry?
- AA, meet a certain level of CP
--> essential AA = LYSINE (most limiting)
153
What protein nutrient requirements do we use for horses?
- CP
- some AA (lysine)
(there is less known about horses)
154
What fat nutrient requirements do we use?
- essential FA (some species)
- otherwise mostly energy
155
What energy (coming from carbs, proteins, and leftover fats) nutrient requirements do we use?
- depends on species and production state
- NE > ME > DE
156
What vitamin and mineral nutrient requirements do we use?
- Ca and P !!
- trace and vitamins (location, species, production, etc)
157
Why are Ca and P important in a diet?
- promote growth
- lactation
- cell signaling
158
define energy
ability to do work
159
What does energy do in our bodies?
gives our bodies the ability to perform cellular processes (work)
160
define work (energy)
energy transferred from one place to another
(move energy where it is needed)
161
define heat
energy transferred from one place to another
(energy given off as heat)
162
What does "making energy" really mean in our bodies?
our bodies can make ATP, and energy carrier
(energy cannot be created)
163
What is the first law of thermodynamics?
energy cannot be created or destroyed, but can be converted between forms
(all energy goes somewhere)
164
What is the second law of thermodynamics?
the universe tends toward maximum disorder
(easier to degrade than synthesize)
165
What is ATP?
Adenosine Triphosphate
- the third (or extra) phosphate group gives it the extra energy
166
The conventional energy scheme partitions energy to describe 2 things:
1. feed (how much ATP an animal can get from a feed)
2. animal (energy requirements)
167
Why is the conventional energy scheme species specific after gross energy?
animals have different abilities to digest
ex: cattle get more (ATP) out of fibers than horses than pigs
168
define gross energy (GE)
total energy in the feed (bomb calorimetry)
169
define digestible energy (DE)
feed "energy" possible for the animal to use (actually digested and absorbed it)
170
define metabolizable energy (ME)
energy that an animal can use in further metabolism
171
define net energy (NE)
what the animal can use for maintenance and extra product/tissue formation
172
explain fecal energy
what cannot be digested and absorbed, the greatest loss in feeds
173
explain gaseous energy
gases coming from the animal (CO2) or the microbes in the LI and RRO (CO2 and CH4), biggest waste product, greatest in ruminants
174
explain urinary energy
minimal losses
175
explain heat increment of feeding (HIF)
- heat of digestion and absorption
- heat of fermentation
- heat of waste product formation and excretion
- heat of product formation
(considered a water but have benefits, ruminants have the most heat of fermentation)
176
What is NEm?
Net Energy Maintenance
1. basal metabolism
2. minimal voluntary movement
3. thermo-regulation
(no change in body size)
177
How can maintenance energy requirements vary?
species, age, BW, breed, sex, physiological state, season/temperature, previous nutrition, current nutrition
178
Are all energy used equally?
NO
179
What is energy used efficiently for?
maintenance rather than product formation
180
define NEr
retained/recovered/product formation
(growing, pregnancy, lactation, work, etc)
181
define what happens when NEm is lower than what the animal needs for maintenance
net energy loss
(not eating enough, losing weight) --> energy deficient
182
define maintenance
0 retained energy, body stays the same size
183
How do we quantify energy?
calories of joules
184
What are some ways we show calories?
kcal or mcal
185
calorie vs Calorie
calorie times 1000 = kcal or Caloire
186
In what two ways do we measure energy?
1. GE = burn it. subtract GE from loses (feed)
2. feed an animal different amounts of feedstuffs and measure animal performance and body weight
187
define monosaccharide
the monomer to a carbohydrate, a single 5 carbon or 4 carbon structure
188
define disaccharide
2 monosaccharides bonded together
189
define polysaccharides
100-1000s of monosaccharides bonded together
190
How many carbons does a pentose have?
5
191
How many carbons does a hexose have?
6
192
examples of pentose monosaccharides
- xylose
- ribose
- arabinose
193
examples of hexose monosaccharides
- glucose
- glalactose
- fructose
- mannose
194
Is there a greater quantity of hexoses or pentoses in feedstuffs and foods?
hexoses
195
examples of disaccharides
- sucrose
- maltose
- cellobiose
- lactose
196
What monosaccharides make up sucrose?
glucose + fructose
197
What monosaccharides make up maltose?
glucose + glucose
(by an alpha 1,4 bond)
198
What monosaccharides make up cellobiose?
glucose + glucose
(by a beta 1,4 bond)
199
What is the difference between maltose and cellobiose if they are both made of glucose?
maltose has an alpha 1,4 bond (starch) and cellobiose has a beta 1,4 bond (fiber)
200
What monosaccharides make up lactose?
glucose and galactose
201
Where do sucrose, maltose, and cellobiose come from?
PLANTS
202
Where does lactose come from?
ANIMALS - milk sugar
203
How do monosaccharides bond?
they will lose H2O and connect through the leftover oxygen
204
Where are polysaccharides commonly found?
found in high quantities in feedstuffs (in plants)
205
examples of polysaccharides
- starch (amylose and amylopectin)
- fiber (cellulose)
206
amylose structure
300-600 glucose strung together in a long chain without any branching
207
amylopectin structure
glucose strung together with branching
208
cellulose structure
100-1000s of glucose constructed in a dense and compacted way, used for the structure of plants
209
Why are plants mostly carbs?
because they perform photosynthesis (make hexoses)
210
What percentage of plants are CHO?
50-80%
211
What percentage of animals are CHO?
less than 1% (glycogen)
212
Carbohydrates general formula
CnH2nOn
213
What are hexoses used for in plants?
- sucrose = energy transport
- starch = energy storage (root, seed)
- cellulose = structure, cell wall
214
What are pentoses used for in plants?
- nucleic acids (DNA and RNA)
- protein
- lipids
215
CHO functions in plants
- energy transport and use (sugars)
- energy storage (starch)
- structure (fiber)
216
CHO function in animals
- energy transport, transfer, and use (blood glucose)
- energy storage (glycogen)
217
Where is glycogen stored in animal?
liver and skeletal muscle
218
Which is more energy dense: glycogen or fat?
fat
219
How much of an animals body is glycogen/CHO?
less than 1%
220
Where do non-ruminants digest CHO?
- small intestine
- large intestine (fibers and CHO not digested in SI)
221
Where do ruminants digest CHO?
- 1st --> ruminal fermentation (RRO) (fiber, starch, sugar)
- THEN --> small and large intestine
222
Where do non-ruminants absorb CHO?
- small intestine (monosaccharides)
- large intestine (VFAs)
223
Where do ruminants absorb CHO?
- RRO (VFAs)
- small intestine (monosaccharides)
224
How does blood glucose levels differ between ruminants and non-ruminants?
ruminants have lower blood glucose than non-ruminants because they have less glucose absorption in the small intestine. Ruminants get their glucose from VFAs absorbed in the RRO (gluconeogenosis).
225
Why do hindgut fermentors have such a wide range of blood glucose levels?
diet dependent
- forage = low blood glucose
- grain = higher blood glucose
226
How do neonatal (baby) ruminants blood glucose levels differ from adult ruminants?
babies do not have a functional rumen yet. When they are born, they will have a low bg similar to their mother and then it will increase to a non-ruminant range
227
list the 3 fates of absorbed carbohydrates in order of priority
1. provide energy now
2. short term energy storage (glycogen)
3. long term energy storage (adipose)
228
What metabolism is happening in the 1st Fate?
- glycolysis
- TCA (tricarboxylic acid) cycle
- ETC / Electron Transport Chain
229
What is going in and out of glycolysis?
- in: glucose (6 carbons)
- out: 2 pyruvate (3 carbons each)
230
What is going in and out of the TCA Cycle?
- in: Acetyl-CoA
- out: reducing equivalents (FADH2 and NADH)
231
What is going in and out of the ETC?
- in: reducing equivalents (FADH2 and NADH)
- out: ATP (~36)
232
How many steps goes glucose need to go through in the first fate of CHO to get ATP?
3
(glycolysis, TCA cycle, and ETC)
233
What metabolism is happening in the 2nd Fate?
glycogenesis
234
define glycogenesis
making glycogen, for short term energy storage (liver and skeletal muscles)
235
define glycogenolysis
breakdown of glycogen, using what was stored as glycogen
236
What metabolism is happening in the 3rd Fate?
lipogenesis
237
define lipogenesis
the production of fatty acids from acetyl-CoA (comes from glycogen)
238
What happens to the energy that is not used in the 1st fate or second fate?
whatever energy is not needed gets stored as glycogen or fat, all carbon gets stored that is not used or wasted (CO2 and CH4 = waste)
239
define adipose
fat, long term energy storage in the body
