Nutrition Exam 2 Flashcards
1
Q
what is the most vital, abundant, and cheapest nutrient for animals
A
water
2
Q
how much of the body weight at birth is water
A
65-85%
3
Q
how much of the body weight at maturity is water
A
45-60%
4
Q
lack of regular water supply results in what
A
production problems
5
Q
animals must always have access to
A
good quality water supply
6
Q
water accounts for how much percent of blood
A
90-95%
7
Q
percentage of body water decreases with
A
- animal age
- body fat
8
Q
the greatest amount of water in the body tissues is present in what kind of fluids
A
intracellular
9
Q
intracellular fluids
A
- accounts for 40% or more of total body weight
- mainly in muscle and skin (most intracellular water is in muscle)
10
Q
extracellular
A
- mainly in intestinal fluids which occupy spaces between cells, blood plasma, lymph, synovial, and cerebrospinal fluids
- 1/3 of the total body water (about 6% is blood plasma)
11
Q
water can serve as what (3)
A
- a solvent
- a transport medium
- a dilutant
12
Q
what are 2 basic functions of water
A
- major component in body metabolism
- major factor in body temperature control
13
Q
transport medium
A
a medium of transportation of semisolid digesta in the GI tract for various solutes in blood, tissue fluids, cells, secretions, and excretion (such as sweat and urine)
14
Q
water serves to transport absorbed substances where
A
to and from their metabolism sites
15
Q
water is a substrate of _____ and a product of _____
A
water is a substrate of hydrolysis and a product of oxidation
16
Q
sources of water
A
- drinking water
- moisture content of feed
- metabolic water (water released through chem. reactions)
17
Q
what is free water
A
moisture content in feeds
18
Q
most dry feeds (grains, hay, etc.) contain how much free water
A
9-13%
19
Q
corn silage contains how much free water
A
65-75%
20
Q
metabolic water is produced when
A
fats, carbs, and proteins are metabolized and oxidized to CO2 and H2O
21
Q
metabolic water can account for how much total water intake
A
5-10%
22
Q
water requirements vary with
A
- heat production
- energy consumption
- dry matter consumption
- seasonal/environmental changes
(species, diet, pregnancy, lactation, tec. can also effect water requirements)
23
Q
what are the different amounts of water consumption in different animals
A
Cattle: 10-20 gallons/day
Horses: 10-20 gallons/day
Sheep: 1-3 gallons/day
Swine: 1-2 gallons/day
Poultry: 2:1 (water to dry feed ratio)
24
Q
water absorption in ruminants happens in what compartment of the stomach
A
rumen and omasum
25
in all species, where is water absorbed
ileum, jejunum, cecum, and colon
26
what causes water loss in the body
excretion (urine and feces), dissipation through skin, vaporization from lungs, sweat, production of milk and eggs
27
why can birds, sheep, and goats go longer without water than many other animals
b/c they excrete less water w/ their waste
28
extracellular water is higher in
males
29
water deficiency causes
- reduced feed consumption (resulting in reduced productivity)
-weight loss due to dehydration
- increased excretion of N and electrolytes
30
how much body water can an animal lose before dehydration occurs
10%
31
good quality water is between how many ppm of total dissolved solids and sulfates
- less than 2500 ppm of total dissolved solids
- less than 500 ppm of sulfates
32
water content in grains is what %
8-30%
33
water content in forage is what %
less than 5% in dry hay
over 90% in young grass
34
water content in silage is what %
65-75%
35
what factors can affect water intake
- temperature and humidity
- dry matter consumption
- dietary factors
- type of urinary system (mammal vs avian)
- water quality
36
what are the chambers in a ruminant stomach
- rumen
- reticulum
- omasum
- abomasum
37
what is the largest compartment in a ruminant stomach
rumen
38
why do ruminants regurgitate food
to break the feed down and increase the surface area for the microbes and enzymes to use
39
description of the rumen
- located on left side of body
- walls contain projections called papillae
- the fermentation chamber
- provides water soluble vitamins and vitamin K, amino acids, and microbial protein
- breakdown of fibrous feeds into VFAs occurs
- VFAs are absorbed through the walls and serve as an energy source
40
description of the reticulum
- not completely separated from the rumen
- walls lined w. mucous membrane w/ honeycomb shaped surface
- honeycombs trap hardware
- walls secrete no enzymes
- move feed into the rumen, omasum, and in regurgitation
41
what is eructation
belching
42
the interior of the rumen, reticulum, and omasum is covered exclusively with what
stratified squamous epithelium
43
explain how the VFAs undergo different degrees of metabolism
acetate and propionate pass through the epithelium largely unchanged, but almost all the butyric acid is metabolized in the epithelium to beta-hydroxybutyric acid (a type of ketone body`)
44
each milliliter of rumen content contains roughly:
- 10-50 billion bacteria
- 1 million protozoa
- variable numbers of yeasts and fungi
45
what does bacteria do for digestion
it carries out most of the digestion of sugars, starch, fiber, and protein in the cow
46
what does protozoa do for digestion
it swallows and digests bacteria, starch granules, and fiber
47
what does fungi do for digestion
they open plant fibers to make them more easily digestible
48
what are some benefits of fermentation
- cellulose and hemicellulose ferment into energy sources
- conversion of non-protein nitrogen (NPN) into protein sources
- synthesis of vitamin K and B
- microbes can attack toxic substances before they enter the rest of the system
49
cellulose can only be broken down by
microbes
50
what happens when microbes die or fall off into the small intestines
they are digested as a high-quality protein source
51
whereas non-ruminants get their protein from feed sources, what must ruminants do
convert their feed into readily available protein
52
in carnivores and omnivores, does fermentation generate few or many calories
very few
53
description of carbohydrates
- primary nutrient component of livestock feeds
- structural and energy reserve of plants
- 70-80% of dry matter of plants are carbs
- less than 1% of animal composition (blood glucose, muscle glycogen)
54
what is the carbohydrate ratioe
1:2:1 CHO
made up of 40% C, 7% H, and 53% O
55
what are the monosaccharides (1 sugar molecule)
- glucose
- fructose
- galactose
56
what are the disaccharides (2 sugar molecules)
- sucrose
- maltose
- lactose
57
what are the polysaccharides (10+ sugar molecules)
- starch
- cellulose
- glycogen
58
how much dry matter of plants are carbohydrates
70-80%
59
starch is made up of what 3 forms
- amylase: 14-30%
- amylopectin: 70-85%
- glycogen: small amounts in the liver and muscle
60
celluloses and hemicelluloses are major components of
plant fiber
61
what is needed to digest cellulose
cellulase
62
cellulose requires what kind of digestion
microbial
63
what linkages do animals need microbes to digest
they need microbes to digest beta linkages b/c they do not make the enzymes to digest them, they can digest alpha linkages without microbes
64
how are carbohydrates made available to cells
- ingestion of glucose or its precursors
- conversion from metabolites
- reactions in the body can make carbs as an end reaction
65
di- and polu- saccharides cannot be digested b/c
they must be hydrolyzed to monosaccharides
66
why can only monosaccharides be absorbed and not other saccharides
b/c monosaccharides are the simplest form of sugar and animals can only digest glucose
67
what are the components of the cell wall
- cellulose
- hemicellulose
- lignin
68
what does salivary amylase do in monogastrics
breaks down starches to maltose
69
pancreatic amylase hydrolyzes what linkages
alpha 1-4
70
what is produced by pancreatic amylase
mono-, di-, and poly- saccharides
71
what are the brush border enzymes
maltase, sucrase, lactase
72
what turns disaccharides into monosaccharides
brush border enzymes
73
what turns polysaccharides into disaccharides
pancreatic juices
74
sucrase turns sucrose into
glucose + fructose
75
maltase turns maltose into
glucose + glucose
76
lactase turns lactose into
glucose + galactose
77
what kind of animals do not have sucrase
ruminants
78
poultry do not have what enzyme
lactase
79
post-gastric fermenters like horses and rabbits can utilize large quantities of
cellulose
80
monosaccharides are absorbed primarily in what part of the digestive tract
duodenum and jejunum
81
carbohydrates are fermented by
microbes
82
in rumen fermentation, what takes the most and least time to ferment
cellulose takes the most time and sugars take the least time to ferment
83
hydrogen is produced in the rumen upon fermentation and is used for
- saturation of fatty acids
- combining with CO2 to produce CH4
- reducing sulfate or nitrate
84
describes cellulolytic bacteria (fiber digesters)
- they produce cellulase
- their primary substrates are cellulose and hemicellulose
- they prefer pH 6-7
- they produce acetate, propionate, little butyrate, and CO2
- they are predominate in animals fed a roughage diet
85
describe amylolytic bacteria
- they digest starches and sugars
- they prefer pH 5-6
- they produce propionate, butyrate, and sometimes lactate
- they are predominate in animals fed a grain diet
86
how is lactic acid formed
by the reduction of pyruvate
87
what are the VFA's
acetate, propionate, butyrate
88
what is acetate used for
energy and fatty acid synthesis
89
what is propionate used for
energy and gluconeogenesis (glucose synthesis)
90
what is butyrate used for
energy and helps convert rumen epithelial cells convert to ketone (beta-hydroxybutyrate)
91
what are the VFA proportions in a normal ruminants diet
60-70% acetic acid
15-20% propionic acid
10-15% butyric acid
92
what are the proportions of gasses in the rumen
60% carbon dioxide (CO2)
40% methane (CH4)
93
in the rumen, nitrate is reduced to
nitrite
94
what is nitrite
an intermediate product that is 10x more toxic than nitrate
95
how can nitrite cause asphyxiation
nitrite comes with hemoglobin to form methemoglobin and be absorbed into the bloodstream, but the methemoglobin cannot bind oxygen so it cannot carry it to the tissues
96
what is the difference between cranial and caudal fermenetation
cranial is pre gastric fermenters
caudal is hindgut fermenters
97
what are the abilities of cranial fermenters (cattle, sheep,and deeer)
- ability to digest and extract energy from cellulose
- ability to utilize the protein from fermentative microbes
98
what are the abilities of caudal fermenters (horses and rabbits)
- ability to digest and extract energy from cellulose
- ability to utilize dietary hexose sources directly
99
which VFAs are the major energy sources (through oxidation)
acetate and butyrate
100
which VFA is reserved for gluconeogenesis
propionate
101
which VFA is the major substrate for lipogenesis
acetate (but propionate is also lipogenic through glucose)
102
what is transamination
the transfer of an amino group from one molecule to another, especially from amino acid to keto acid
103
how can CHO convert to proteins
through transamination
104
fermentation of starch and cellulose in the lower digestive tract of nonruminants produces
VFAs
105
absorbed glucose and that resulting from gluconeogenesis can be stored in limited amounts as liver and muscle glycogen or converted to
body fat by breakdown to pyruvate
106
abnormal carbohydrate metabolism in animals is associated with
diabetes and ketosis
107
what methods are standard procedures for predicting the digestible energy content of feeds high in plant cell wall constituents
Van Soest NDF methods
108
what is the major constituent of plant cell walls
cellulose
