Digestive Anatomy Flashcards
(139 cards)
1
Q
What is nutrition?
A
the process by which an animal takes and utilizes food substances
2
Q
What is a nutrient?
A
any chemical element or compound in the diet that supports normal life processes
3
Q
What are the nutrient categories?
A
- vitamins
- minerals
- water
- protein
- lipids
- carbohydrates
4
Q
What are the required nutrients?
A
- water
- protein
- minerals
- vitamins
- energy (composed of lipids and carbs)
5
Q
What are the 3 functions of a nutrient?
A
- structural role
- energy source
- regulation
6
Q
Whats an example of a nutrient performing a structural role?
A
lipid bilayer, minerals used for bone health
7
Q
Whats an example of a nutrient performing a energy role?
A
cells need ATP which they get by breaking down carbs and lipids
8
Q
Whats an example of a nutrient regulating?
A
vitamins regulate enzyme activity or function in gene transcription
9
Q
What is feedstuff?
A
any material used for feed (individual components)
10
Q
What is a diet?
A
mixture of feedstuffs that supplies nutrients to the animal
11
Q
What is a ration?
A
daily allowance/amount of feed provided to an animal
12
Q
What is a meal?
A
feed thats consumed by an animal on a regular basis
13
Q
What is feeding behavior?
A
what material the animal is consuming
14
Q
Carnivorous Feeding Behavior
A
adapted to consuming meat based diets/feedstuffs
-simple, short digestive tract
ex: cats
15
Q
Omnivorous Feeding Behavior
A
adapted to consuming a combination of plant & meat based food stuffs
-simple, longer digestive tracts
ex: dogs, chickens, pigs
16
Q
Herbivorous Feeding Behavior
A
adapted to consuming plant material
-most complex digestive tracts bc of microbial fermentation
ex: cows, horses, sheep, goats, rabbits, rodents
17
Q
What are the ruminant feeding strategies?
A
1: Concentrate selectors
2: Bulk and Roughage eaters
3: Intermediate feeders
18
Q
Concentrate selectors
A
select the more nutrious, lower fiber parts of plants
-less microbial fermentation so smaller rumens
ex: deer, giraffes
19
Q
Bulk and roughage eaters
A
consume large quantities of high fiber material
-large rumens
ex: cows
20
Q
Intermediate feeders
A
can adapt to either a concentrate selector or bulk & rougher
21
Q
Mouth
A
-prehension
-mastication
-salivation
-formation of bolus
-swallowing
22
Q
prehension
A
obtaining food (using lips, tongue, teeth)
23
Q
mastication
A
mechanical breakdown of food (teeth)
24
Q
salivation
A
-begins the breakdown of starch
-moistens food
-kills microbes
25
esophagus
transports food bolus to the stomach
26
stomach
secretion of digestive enzymes enzymes/ HCL to begin chemical digestion
27
small intestine
-chyme/digesta enters from the stomach
-pancreas secretes digestive enzymes into duodenum
-chemical digestion continues
-absorption of nutrients occur
28
What does the duodenum secrete?
cholecystokinin
29
What does Cholecystokinin do?
acts on pancreas to to secrete digestive enzymes and the gallbladder to secrete bile into duodenum
30
What is the surface of the SI?
epithelial tissue
-epithelial cells/ villi
-microvilli
-brush border
31
Whats a villi (projection) consist of?
simple columnar epithelial cells are arranged into villi
32
Where are microvilli (tiny projections) found?
apical surface of the epithelial cell
33
What are glycoalyx?
mesh like projections on top of microvilli
34
What makes up the brush border? What happens there?
both the glycoalyx and microvilli
this is where digestion ends and absorption starts
35
What are the three parts of the large intestine?
1. colon
2. cecum
3. rectum
36
What happens in the colon?
water absorption
37
What does the cecum deal with?
microbial fermentation
38
What happens in the rectum?
formation of feces
(which gets excreted through the anus)
39
What does the crop do?
stores food and moistens food
40
What does the proventriculus?
beginning of chemical digestion
41
What does the gizzard do?
mastication/mechanical digestion
42
What happens in the pair of ceca?
microbial fermentation
43
Whats the cloaca do?
common opening for digestive, reproductive, & urinary tracts
44
Whats the vent?
exterior opening
45
In a ruminant the esophagus empties into the
reticulo-rumen junction
46
What happens in the reticulum?
traps foreign material
47
Whats happens in the rumen?
- microbial fermentation
- produces volatile fatty acids that are absorbed through the rumen wall
48
What does the omasum do?
filtration by particle size
49
What happens in the abomasum?
chemical digestion
50
What are the advantages of a ruminant compared to monogastrics?
-utilization of fibrous foods
-microbes produce protein from ammonia & carbon sources
-microbes produce all B vitamin & vitamin K
51
What are the disadvantages of a ruminant compared to monogastrics?
-energy loess due to heat & gas production
-loss in protein quality due to synthesis of microbial protein
52
protein quality in ruminant
high quality is a waste bc the microbes change the structure of the amino acids
53
Foregut fermenters
-have stomach compartment where microbial fermentation occurs
-do not have stomach compartments
ex: hippo, sloths
54
Colon fermenters
majority of microbial fermentation occurs in enlarged colon
ex: horses
55
Cecal fermenters
majority of microbial fermentation occurs in enlarged cecum
ex: guina pigs, rabbits
56
Cecal fermenters have 2 types of feces
1. hard pellets (normal)
2. soft pellets: result from contractions of cecum consumed directly from anus
57
Whats coprophagy?
eating feces
58
What are the advantages of hindgut compared to ruminator?
-better adapted to high fiber, low quality diets
-rate of passage is not regulated by omasum
-higher rate of passage that allows for higher consumption
59
What are the disadvantages of a hindgut compared to ruminants?
-nutrients provided from fermentation are less available
-microbes get less nutritious substance for fermentation
60
Evaluating feeds: What do we need to know in order to efficiently utilize feeds?
-nutrition composition
-digestibility
-dry matter/as fed
-cost
-presence of toxins/ inhibitors
61
Feedstuff sampling
values of nutrient content are of no practical use if the sample tested is not representative of the feedstuff as it is fed to animals
62
Sampling hay
use hay probe which bores into bale of hay
-do 10-20 times
63
Pasture sampling
using 1ft by 1ft square & cut to grazing height
-do 10-20 times
64
Grain test
use grain probe for 10-20 samples
65
Feed microscopy
checks for contamination
used for regulatory purposes
66
Proximate analysis of feeds
standard system of chemical methods of feed analysis
67
Dry matter
drying feed sample to constant weight
-getting a dry sample allows you to measure amount of water in sample
68
Nutrient concentrations are
always higher on a DM basis
69
Crude protein
estimated by measuring nitrogen content of feed multiplied by factor of 6.25
-estimates protein composition through measuring nitrogen
70
Ether extract
crude fat estimate
-extract fat from sample with ethyl ether
-will extract all facts in sample, including waxes which are not digestible
71
Ash
measures inorganic portions (minerals)
-quantitive measure only
72
Crude fiber
not a reliable method and not very accurate
-estimates indigestible portion
73
NDF
-neutral detergent fiber
-uses a neutral detergent to solubilize cell contents
-leaves hemicellulose, cellulose, and lignin
(not digestable in monogastrics)
74
ADF
-acid detergent fiber
-uses an acid detergent to solubilize hemicellulose
-leaves cellulose and lignin (true fibrous components)
75
Nitrogen-free extract
estimates available carbohydrates
-a calculated value
NFE = 100 - (water + CP+ CF+ EE+ ash)
76
Estimating the energy content of feeds
total digestable nutrients (TDN)
sums all fractions of feed that are digestible
77
Determination of specific nutrients
proximate analysis gives general indication of nutrient content
-can measure individual amino acids, minerals
78
Energy content of feed is determined by what?
a bomb calorimeter
-tells us nothing about how energy can be used by an animal
79
What is digestible energy?
gross energy- fecal energy
-how much energy is digested and absorbed
80
What is metabolizable energy?
digestible energy - urine energy - gas energy
-how much is available for cells to use for metabolsim
81
What is net energy?
metabolizable energy - heat increment
-how much is available minus all loses and the expense of use of energy
82
Net energy options
-production
-maintenance
83
Assessing digestabilibty options
-total collections in metabolism crate
-using collection bags
-nylon bags (ruminants)
-using fecal marker
-illeal digestibility
*methods yield apparent digestibility not true digestibility
84
total collections in metabolism crate
feed the animal a known amount of the feedstuff then collect all the feces
-measure the nutrient content of the feedstuff & feces
-calculate % digestibility
85
using collection bags
feed animal feedstuff & collect feces in bags attached to the animal
-measure nutrient content of feedstuff & feces
-% digestibility (for each individual nutrient)
86
Nylon bags
put feedstuff in bag and insert bag into rumen
-remove bag over set amount of time
-measure nutrient concentrations of the feedstuff vs what is left in the bag to determine rumen digestibility
87
using fecal markers
add known concentration of an indigestible marker to the feed
-collect feces when marker appears in the feces
-compare nutrient concentration to fecal marker concentration
88
Illeal digestibility
feed animal
collect contents of the ileum to determine digestibility
89
true digestibility
accounts for endogenous losses throughout the digestive tract
-measure apparent digestibility & then use a correction factor that is species specific
90
Feed manufacturing
-process of converting raw materials into balanced diets
-produced in feed mills
-usually pelleted or meal type feed
91
Specialty feeds
horse, rabbit, llama, pet foods, calf milk replacers, calf growers rations
92
Modern feed mills are
computer controlled
93
Least Cost Rations
-select lowest cost feedstuffs
-feedstuffs that make up the ration will change overtime depending on the costs of feedstuff
94
Association of American Feed Control Officials
-set standards for quality and safety of animal feed and pet food
-establishes ingredient definitions
-not a regulatory organization
95
FDA
sets and enforces animal feed regulation
96
Feed label information required by law
-net weight
-product name, brand name
-guaranteed analysis
-common name of ingredients
-name and mailing of address of manufacturer
-directions for use
-precautionary statements for safe use
-nutritional adequacy statement
-species the food is for
97
Guaranteed analysis
required to have:
-min % crude protein
-min % crude fat
-max % crude fiber
-max % moisture
*expressed on an as fed basis
98
labels without maximum % moisture are assumed to be air dried
10% moisture
90% DM
99
Limitations of information on feed tag
-no info regarding protein quality
-digestible or metabolizable energy value is not known
100
use of drugs in fed is regulated by the FDA
-degree of regulation based on potential risk to humans from drug residues
-all drugs placed into categories based on risks
101
feed mixing
much feed manufactured on farms as opposed to commercial feed mills
102
feed mixing equipment
-raw materials ground
-efficiency of mixing influenced by order of addition of ingredients
103
how to mix feeds
-first add ingredients that make up majority of diet
-next add liquids slowly
-then add ingredient that make up less than 2.5% of fat
-mix for 15-20 mins
104
Pelleting
forcing mixed feed ingredients through a pellet pie
105
Advantages of pelleted feeds
-increases bulk density
-increases feed intake
-prevents sorting
-reduced dust
106
What's the biggest concern with pellet quality?
crumbling
107
Feed is preconditioned with steam before pelleting
activates functional properties in feedstuffs allowing pellet binding
-can add pellet binders to hold pellets together
108
What has good functional properties?
wheat gluten
109
What has bad functional properties?
corn, sorghum, rice, oats
110
True of false: rarely feed whole grains or seeds
true
111
other processing methods
-grinding in hammermill
-dry or steam rolling
-flaking
-popping
-micronized grains
-tempering
-extrusion
112
feed efficiency
represents how well an animal can convert feed to product
-the closer the feed efficiency is to 1, the more efficient the animal is at converting feed to product
*product output/ feed input
113
feed conversion factors
amount of feed: amount of product
114
feeding trials
feed intake measurements
-have animals in pens
-feed each pen a known amount of feed
-next day, measure feed refusal
-difference b/w what was fed vs refusal is daily FI
115
Maximum feed intake can only be achieved w/
access to free choice water
(separate and access at all times)
meanwhile Ad libitum is not separate
116
What feed properties may affect feed intake?
-palatability
-energy
-protein/amino acid concentration
-forage composition
others: temperature, pregnancy, conditioning, body size, smell, fatigue
117
Palatability
taste, olfaction, texture
118
Feed preference tests can be performed
-2 different feeds on scales
-give animal access to both feeds at the same time
-animal eats more of what the animal prefers
119
If feeds are sufficiently palatable, dietary energy concentration will
control voluntary FI
-animals will eat to meet their energy requirements
120
distension feedback
-stomach distends as it fills with food
-receptors on stomach wall will send signals to satiety centers in brain to stop eating
121
With a low energy/fibrous diet
the stomach fills quickly
122
high energy diets
do not provide as much distension feedback as low energy diets
123
Chemostatic feedback
increases in blood metabolites will signal to satiety centers to stop eating
-glucose, VFA
124
What is rumen fill/distension feedback affected by:
-NDF
-water content
125
NDF
higher NDF, the more space it will take up in rumen causing distension feedback
126
Water content
higher water content of forage, the bulkier the forage will be causing distension on feedback
127
What is feed intake affected by in monogastrics
essential amino acids
128
What is feed intake affected by in ruminants
-bypass protein (bypasses microbial fermentation) : increases FI
-nitrogen: select feeds with higher N content
129
Environmental temperature affects on feed intake
FI increases as temp decreases
130
Comfort zone of an animal
range of temperatures where metabolism is at a min
131
When temps go below comfort zone,
feed intake increases as metabolism increases to maintain body temp
132
Heat increment of feedstuff
extra heat produced due to the metabolism of a nutrient
-protein has the highest
133
Reproduction FI
-decrease in FI during late gestation
-increase in feed intake during peak lactation
134
Neophobia
reluctance to accept a new food
135
aversive conditioning
train to avoid certain foods
136
how does metabolic rate affect FI
animals w/ increased metabolic rates consume more food per unit of BW
137
metabolic body size =
(BW) x .75
-can use to compare FI across species
138
how does smell play a role?
animals may reject a feed without even tasting it
139
how does fatigue play a role?
animals may become fatigued in seeking, ingesting, chewing, and ruminating feed
