Exam 1 Flashcards
Nutrition definition: utilization of foods by living organisms for _______. (5)
growth, reproduction, production, performance, and maintenance of health
What are nutrients?
substances and/or qualities of foods required for life, growth, maintenance, and repair of body tissues
What are the 2 broad groups of nutrients?
organic compounds
inorganic elements
Examples of nutrients as classes of substances (4)
Fiber
Energy
Omega-3 fatty acids
Vitamin A
What “nutrient” class of substances is = bioavailable chemical bond energy in organic substances?
energy
What “nutrient” class of substances is = many substances that are variably water soluble + fermentable by GI tract microbes?
fiber
What “nutrient” class of substance is = fatty acid w/ double bond between 3rd & 4th carbons from methyl terminus?
omega-3 fatty acids
What “nutrient” class of substance is = organic substances that have varying vitamin A activity?
Vitamin A
What is an “essential nutrient”?
substance required for life that can’t be synthesized or synthesized in sufficient amount
A “conditionally-essential nutrient” is a substance that is essential under certain conditions such as ____ or ____.
physiological stage or disease state
What are the 6 essential nutrients for most animals?
- water
- energy
- amino acids
- minerals
- vitamins
- fatty acids
What is the essential nutrient with the greatest mass of daily intake?
water
Which essential nutrient has the greatest mass of a diet when water is not considered?
energy
Which nutrient is half essential, half conditionally-essential and in about 20 diets?
amino acids
Which essential nutrient is classified by quantity of dietary requirement?
minerals
List a few examples of macrominerals
Ca, P, K, Cl, Na, Mg, S
List a few examples of trace or microminerals
zinc, iron, manganese, copper, molybdenum, iodine, selenium, cobalt, chromium
Which essential nutrient is an organic compound with low concentration that are variably provided in foods and broadly classified by solubilities?
vitamins
What are the 2 classes of vitamins?
fat soluble vitamins
water soluble vitamins
Which vitamins are fat soluble?
vitamins A, D, E, K
Which vitamins are water soluble?
thiamin, riboflavin, niacin, biotic, folic acid, pantothenic acid, B6, B12, C
Which essential nutrient is most abundantly in diet esterified in triacylglycerol?
fatty acids
2 categories of fatty acids
Omega-6 or n6 series
Omega-3 or n-3 series
Which category of fatty acids are a-linolenic acid, EPA, DHA in?
omega-3 or n-3 series
Which category of fatty acids are linoleic acid and arachidonic acid in?
omega-6 or n-6 series
Nutrients must be provided in proper _____ and _____ relative to one another.
amounts
proportions
Deficiency (too little), excess (too much), or disproportion of nutrients = _______.
malnutrition
Nutrient amount and proportion needs to vary with ______ and _____.
physiological state
diseased states
What are 4 examples of physiological state important for varying nutrient amount & proportion?
- growth
- maintenance
- gestation
- lactation
What is “a concept of animal response to nutrient intake”?
optimal nutrition
For optimal nutrition, nutrients are provided in amounts of proportions that optimize a ______ or ______ important response.
physiologically
economically
The Nutrient-Animal Response Relationship Curve has ______ on the x-axis and ______ on the y-axis.
concentration of a nutrient
animal response
What is the portion of the Nutrient-Animal Response Relationship Curve when the response variable increases with increasing nutrient concentration?
deficiency range
The deficiency range of the nutrient-animal response relationship curve indicates the diet has ______.
too little nutrient
What is the part of the Nutrient-Animal Response Relationship curve where the response variable increases with increasing nutrient amount, but with diminishing returns with further increases in nutrient amount?
suboptimal range
(T/F) The suboptimal range of the nutrient-animal response relationship curve is never desired for companion animals.
False - condition usually not desired
Suboptimal range sometimes is sought for _____ or _____.
health or economy
What is the part of the nutrient-animal response relationship curve where the response does not change with increasing nutrient amount?
optimal range
What is the part of the nutrient-animal response relationship curve where the response decreases with increasing nutrient amount?
excess range
Which condition is usually desired on the nutrient-animal response relationship?
optimal range
Excess of a nutrient may cause _____ of another?
deficiency
Determining optimal nutrient concentration can be difficult because why?
- more than one response variable can determine the optimal nutrient amount
- body reserves of nutrient affect response to dietary concentration
What is “nutrient requirement”?
minimum dietary amount of highly bioavailable nutrient that optimizes a response important to physiological function
What term means “readily obtained from diet for use in tissues”?
bioavailable
A highly bioavailable nutrient is efficiently _____ and ____.
digested
absorbed
A nutrient requirement varies with _______.
physiological state
Nutrient requirements for lactation are usually (greater than / less than) nutrient requirement for growth.
greater than
What is the “minimum dietary amount of a nutrient that should be presented in practical formulation that maintains health”?
nutrient allowance
Nutrient allowance is for ____, not a single response variable.
health
Nutrient allowance is typically (greater than / less than) its corresponding nutrient requirement.
greater than
(T/F) Nutrient requirement = nutrient allowance + safety factor.
False: nutrient allowance = nutrient requirement + safety factor
Why is a safety factor used in determining nutrient allowance? (4)
- bioavailability < 100%
- nutrient content of ingredients varies
- individuals vary in ability to assimilate nutrients
- nutrient requirements are extrapolated across species
Shortfalls of nutrient allowances (regarding safety factors) (3)
- SFs theoretical, not empirical
- SFs based on incorrect assumptions (bioavailability & nutrient contents in ingredients)
- SFs don’t account for dietary interactions that affect bioavailability
(T/F) There is no one best diet or food for any animal species.
True (many combos can suffice)
(T/F) Knowing nutrient composition of any diet with complete certainty is simple.
False - difficult
What are 3 useful estimates of dietary nutrient composition?
- proximate analysis
- guaranteed analysis
- average nutrient content
Proximate analysis is also known as _____.
Wende Analysis
Proximate analysis is a __________ of dietary nutritional value, used by regulators.
crude estimation
What 6 physical-chemical characteristics are used for Proximate Analysis?
- moisture
- crude fat
- crude fiber
- ash
- crude protein
- nitrogen free extract (NFE)
What is a good estimate of water content of a diet?
moisture
What is a rough estimate of dietary fat?
crude fat
What is a rough estimate of dietary fiber?
crude fiber
What is a rough estimate of dietary mineral content?
ash
What is a rough estimate of protein content in a diet?
crude protein
What is a rough estimate of the digestible carbohydrate content of a diet?
nitrogen free extract (NFE)
Nitrogen free extract is the weight of “as is” (plus/minus) the sum of weights of moisture, crude fat, crude fiber, ash, and crude protein.
minus
What is “a listing of proximate analysis results” and other assay results ‘guaranteed’ by the manufacturer”?
guaranteed analysis
Guaranteed analysis is of value but limited because results of the “analysis” are: (3)
- minimums or maximums
- often incomplete listings
- derived from proximate analysis
What is better than proximate and guaranteed analyses for assessing nutritional adequacy?
average nutrient content
The bulk of ___ is used for fulfilling an animal’s need for energy.
dietary dry matter weight
What is the primary cost of feeding animals?
provision energy
What is the variable of primary importance of deciding how much diet is to be fed?
energy
All nutrients much be provided in proper _____ to dietary energy.
proportion
(T/F) Animals eat for a sensed deficiency of other nutrients like proteins, minerals, or vitamins.
False!
Why do animals eat?
for energy
What does the energy density of a diet determine?
whether concentration of a nutrient in a diet is adequate
4 ways the energy value of diets are quantified (4)
- calorie
- kilocalorie
- megacalorie
- joule
What is “the amount of heat required to raise the temp of 1g of water from 14.5 to 15.5 C.
calorie
(T/F) The calorie is too small for general use in nutrition.
True!
What is the standard abbreviation for kilocalorie? How many calories are in a kilocalorie?
kcal
1000 calories
How many kilocalories are in a megacalorie?
1000 kcal
What is the “international standard energy unit”?
joule
What 4 systems are used to measure diet energy content?
- gross energy (GE)
- digestible energy (DE)
- metabolizable energy (ME)
- net energy (NE)
What is the energy value of a diet estimated from heat released from complete combustion in oxygen atmosphere?
gross energy
Gross energy represents a theoretical ________ energy that can be obtained from a foodstuff.
maximum possible
Gross energy can be estimated without a bomb calorimeter by using assumed _______ for protein, fat, and carbohydrate.
average gross energy values
Crude protein gross energy value (GE)
5.65
Crude fat gross energy value (GE)
9.40
Carbohydrate (nitrogen free extract) gross energy value (GE)
4.15
(T/F) The gross energy of a food gives little information of the actual energy available to an animal.
True
Digestive Energy =
DE = gross energy of food minus gross energy of feces
DE = GEfood - GEfeces
Digestible energy is sometimes termed _____ because feces contain more than undigested food.
apparent digestible energy
Digestible energy calculation accounts for _______.
digestibility of protein/fat/carb
uses “digestibility coefficients”
Digestibility coefficient of crude protein
0.861
Digestibility coefficient of crude fat
0.951
Digestibility coefficient of carbohydrate
0.764
What is the definition / equation for Metabolizable Energy (ME)?
ME = gross energy food minus gross energy feces/urine/combustible gases
ME = GEfood - (GEfeces + GEurine + GEgases)
Why can’t all energy in food be used in metabolic processes? (2)
- some chemical bond energy lost in urine
- some food energy lost in fermentation by microbes
What two combustible gases can some chemical bond energy in food be lost from?
methane
hydrogen
Which species does substantial microbial fermentation occur in?
ruminants
those with extensive post-gastric fermentation
Metabolizable energy values are also known as ________ and are assigned to protein, fat, and carbohydrate.
physiological fuel values
Crude protein physiological fuel value
3.5
Crude fat physiological fuel value
8.5
Carbohydrate physiological fuel value
3.5
Metabolizable energy values assigned to protein/fat/carb for human diets are (greater/less) than those for dog/cat diets because digestion coefficients of dog/cat are assumed to be (more/less) than human food.
greater
less
Metabolizable energy values of protein/fat/NFE are also known as __________.
modified atwater factors
The total digestible nutrient system provides energy index value for diets for what kind of animals?
herbivores
Total digestible nutrient system (TDN) estimates in terms of _______-equivalent energy.
carbohydrate
Total digestible nutrient system usually (underestimates/overestimates) available energy.
overestimates
What two energy types are usually overestimated in Total Digestible Nutrient System?
carbohydrate energy
fiber energy
The Net Energy (NE) of a diet was developed for estimation of energy requirement in growing animals, particular in ______.
cattle
How does the Net Energy (NE) differ from Metabolizable Energy (ME)?
subtracts heat increment
(energy loss in heat)
Heat increment (used in Net Energy) is also called ______.
specific dynamic action
Heat increment varies based on what?
physiological state
(T/F) Heat increment for maintenance is greater than gain.
False - gain > maintenance
What state is “when body mass & energy content is constant”?
maintenance state
(T/F) In the Maintenance State: energy of food is completely utilized (no net storage or loss) and all energy released from food is released as heat.
True
What is “the amount of energy required to sustain the maintenance state”?
maintenance energy requirement (MER)
MER (maintenance energy requirement) is a sum of what 4 categories?
- heat increment
- basal metabolism
- physical activity
- body temp regulation
Heat increment is energy used in _____, _____, and ______ of food.
digestion
assimilation
metabolism
Heat increment of ruminants is (small/large) and (greater/less) than 30% of the MER.
large
greater
Due to the heat increment, feeding ruminants is (advantageous/hindrance) in cold temps, while (advantageous/hindrance) in warm temps.
advantageous
hindrance
What is the largest component of MER (maintenance energy requirement)?
basal metabolism
Basal metabolism is mostly processes of _______.
cellular maintenance
What term refers to “the energy need/use of basal metabolism”?
basal metabolic rate (BMR)
What 4 conditions is BMR determined from?
- post-adsorptive state
- awake
- at rest
- thermoneutral environment
BMR = __ x Mkg^__.
BMR = 70 x Mkg^0.75 (kcal/day)
BMR on a per kilogram basis (increases/decreases) as animal body mass (increases/decreases).
decreases
increases
What is a commonly use approximation of BMR?
resting energy requirement (RER)
Because most hospitalized animals are minimally active and not eating much, what equation is used to estimate RER (resting energy requirement)?
BER equation
RER (~=BMR) = 70 x Mkg^0.75 (kcal/day)
For animals between ___ and ___ kg, a common linear transformation of RER equation is used.
2 & 45
What is the linear transformation of RER equation used for animals 2 to 45 kg?
RER = 30 x Mkg + 70 (kcal/day)
(T/F) Energy of physical activity is variable in animals at the maintenance state.
True
What are 2 examples of thermal regulation in cold environments?
shivering & non-shivering thermogenesis
What are 3 examples of thermal regulation in hot environments?
panting
gular fluttering
sweating
Using body weight, an equation is calculated using a(n) _______ to estimate MER. (MER = RER x ______).
activity factor
Activity factor for neutered adult dogs
1.6
Activity factor for intact adult dogs
1.8
Activity factor for inactive/obese prone adult dogs
1.2 - 1.4
Activity factor for neutered adult cats
1.2 - 1.4
Activity factor for intact adult cats
1.4 - 1.6
Activity factor for inactive/obese prone adult cats
1.0
Adult ______s for which MER is unknown, MER is roughly twice RER.
mammals
MER = RER x ~2
(T/F) Great variation is observed in MER within populations of animals.
True
Variation in MER within populations of animals is due to ______ and ______ differences.
activity & energy efficiency
Growth is more energetically demanding than maintenance because:
support current body tissues +
expand body tissue mass
Energy requirement for growth varies with ______.
maturity
MER during weaning
2.0
MER at 40% grown
1.6
MER at 80% grown
1.2
(T/F) DERgrowth (daily energy requirement during growth) requires re-estimation depending on body condition.
True
What two things are more energetically demanding than maintenance and growth?
gestation + lactation
Why are gestationlactation more energetically demanding than maintenance/growth? (2)
- energy put into products
- energy expended in making of products
DERgestation of dogs does not need to increases much above MER until _____.
last third of gestation
(T/F) DERgestation of cats increases substantially from conception to gestation.
False - linear!
Which physiological state has the most demanding daily energy requirement?
lactation
DERlactation greatly increases with increasing ______.
litter size
For determining DER during pregnancy, use a multiplier of MER depending on _______.
gestational stage
For determining DER during lactation, use a multiplier of MER depending on ______.
litter size
The energy requirement in illness/injury is often (lower/higher) than MER.
lower
(T/F) The energy requirement in most illness/injury states “initially” should be assumed to be no more than RER.
True
____ can be used to estimate ideal weight for overweight patients.
RER
Purina 9-point BCS: what percent of body fat does a patient have from score 5/9-9/9?
5/9: 20%
6/9: 25%
7/9: 30%
8/9: 35%
9/9: 40%
When can patients be fed above RER (still not greater than preg/lactation/growth)?
very severe injury
The increase in energy requirement in severe injury is usually only as great as ____.
MER
(T/F) Underfeeding patients can be worse than overfeeding.
FALSE - overfeeding can be worse
Why can overfeeding be worse than underfeeding?
- regurg/V+/D+ (feeding tube/catheter)
- metabolic derangements
What are a few examples of metabolic derangements that can occur with overfeeding of patients?
hypokalemia
metabolic acidosis
hyperglycemia
over-hydration
Which type of animal are carbs essential? Which are mostly non-essential?
herbivores
dogs/cats
Bioavailable carbohydrate is (less/more) expensive energy than protein/fat.
less
Bioavailable carbohydrate is substituted for fat/protein in some diets for what purpose?
therapeutic diets to manage disease
Bioavailable carbohydrate is conditionally essential in dogs when ____ is marginal.
dietary protein
(T/F) Bioavailable carbohydrate is conditionally essential in cats when protein is marginal.
False - not nutritionally essential
When dietary protein is low, what are 2 benefits for carbohydrate in cat diets during lactation?
- reduce lactational weight loss
- reduce mobilization of protein in lactation
3 types of commercial dog/cat foods with carbohydrate
- extruded/expanded dry (kibble)
- semi-moist
- canned/wet
Kibble/dry-type diets contained >30% carbohydrate as _____.
starch
Extrusion of dry diet types requires that ingredients contain sufficient starch to form _______?
gelatinized-dough
What are two reasons carbohydrates are used in semi-moist diets?
preservatives
humectants
Two examples of carbohydrates in semi-moist diet?
sucrose
high-fructose corn syrup
(T/F) Propylene glycol is a non-carbohydrate humectant alternative for dog and cat foods.
False - NOT in cat food!
Propylene glycol induces oxidative damage in ______ of cats and causes what disease?
RBCs
Heinz bodies / anemia
(T/F) Canned cat food but not dog food is typically low in carbohydrate.
True
Saccharides are carbohydrates that are made of what two chemical compoounds?
polyhydroxy aldehydes
ketones
Carbohydrates are (first/second) reaction derivatives.
first
What is an example of a first reaction derivate of carbohydrate which is a phosphate-containing saccharide found in cereal brans?
phytates
Phytates substantially bind _____.
cations
4 types of carbohydate polymers
monosaccharides
disaccharides
oligosaccharides
polysaccharides
3 important monosaccharides
hexoses (glucose, fructose, galactose)
3 important disaccharides
lactose
sucrose
lactulose
What type of carb polymer has 3 to 10 monosaccharides?
oligosaccharide
Two examples of oligosaccharides
raffinose
stachyose
Two main classes of polysaccharides
starches
fibers
3 examples of starches
amylose
amylopectin
glycogen
4 examples of fibers (polysaccharide)
hemicellulose
cellulose
pectins
gums
Chemical structure of lactose (linkage + 2 molecules)
B 1,4 linked glucose + galactose
What disaccharide is not readily digested in adults?
lactose
Chemical structure of lactulose (linkage + 2 molecules)
B 1,4 linked galactose + fructose
Which disaccharide is the primary carb in milk?
lactose
Lactose contributes to ____ and ____ of milk.
energy
osmolarity
What species does not digest lactose?
birds
Why is lactose not readily digested in adults?
animals have alpha 1,4 linkages that are digested, while lactose has B 1,4
Which disaccharide is used clinically and not absorbed/digested/hydrolyzed by mammalian enzymes?
lactulose
Sucrose chemical structure (linkage + 2 molecules)
a 1,4 linked glucose + fructose
(T/F) Cats are indifferent to sucrose/sweet substances.
True
If sucrose is too high, cats can develop _____.
fructosuria
Which disaccharide has a positive effect on the acceptability of food and digested by dogs & cats but can cause dental cavities?
sucrose
Starch chemical structure (linkage + molecules)
a 1,4 + 1,6 linkages of glucose
Starch can be in straight chains (_____) or chains with branches (______).
amylose
amylopectin
______ occur in semicrystalline granules that are variably resistance to _____.
plant starches
digestion
______ cause gelatinizing of starch granules which increases ____ of starches.
high moisture/heat
digestibility
What is “a proteinacous by-product starch extraction from grains?
gluten
Glutens have (low/high) water solubility but structure varies with grain.
low
(T/F) Wheat gluten is often associated with food hypersensitivity in dogs.
False - rarely
Why are plant starches not well tolerated in neonates?
lack sufficient amylase activity to readily utilize starch
Which polysaccharide is densely packed, water-insoluble material in plant cell wall fibrils?
cellulose
Cellulose chemical structure + molecule
B 1,4 linkages of glucose
Cellulose’s structure prevents digestion by ____ enzymes
animal
_______ slowly ferment cellulose
GI microbes
Why can microbes ferment cellulose while they cannot be digested by animal enzymes?
microbes produce B 1,4 glucosidases unlike animals
Organic acids from cellulose by microbes fermentation are a substantial energy source for what kinds of animals?
ruminants
post-gastric fermenters
Which polysaccharide is chemically/structurally different from cellulose with 50 to 200 units in length with branching?
hemicellulose
Hemicellulose is (soluble/insoluble) in water and (can/cannot) be digested by animals.
insoluble
cannot
Which polysaccharide is found in plants but DOES provide good water solubility (unlike cellulose/hemicellulose)?
pectins + gums
Which polysaccharide is a water-insoluble polymer of amino sugars found in fungi, yeast, and invertebrates?
chitin
(T/F) Chitin is not digested by animals but fermented by GI microbes.
True
What substance is “structurally diverse, considered to be remnants of edible plant cells including polysaccharides, lignin, other substances resistant to digestion by animal host”?
dietary fiber
What are 3 examples of non-polysaccharide dietary fibers?
lignin
cutins & suberins
What dietary fiber gives a “woody” quality to plants and water insoluble?
lignin
(T/F) Lignin cannot be digested by host OR GI microbes.
True
What dietary fibers give “waxy” qualities to plants?
cutins + suberins
What non-polysaccharide dietary fiber is polyfunctional phenol polymers infiltrated through cellulose of plant cells?
lignin
3 properties of dietary fiber
- not digested by host
- variably water soluble
- variably fermentable by GI microbes
4 uses of dietary fiber in dogs/cats
- weight reduction
- treat chronic diarrhea
- up fecal bulk/moisture
- manage diabetes mellitus
Term for “categorical reference to lipid in food”
fat
Term for “food lipids that are liquid at room temperature”
oils
Term for “food lipids are that solid at room temperature”
fats
Food lipids are (soluble/insoluble) in organic solvents.
soluble (ex. ether)
Most dietary fat is _______ (structure)
triacyglycerol
_____ is the largest body store of triacylglycerol.
adipose
Lipid structure
glycerol backbone + fatty acid chains
The functional importance of dietary fats is provision of ______ and _____.
energy and nutrients
Fat has ____ times more ______ energy than protein & carbohydrate on a weight basis.
2.25
metabolizable
Fat is used to increase dietary energy ______ for certain conditions.
density
Fat increases energy density/mass of diet for what conditions?
lactation, growth, physical performance
clinical conditions (assisted feeding, can’t chew, aged horses)
2 essential fatty acids that dietary fat provides
omega-6 & omega-3 fatty acids
Dietary fat is essential for absorption of some ______.
vitamins
Which vitamins are fat-soluble?
A, D, E, K
Reason fat is used that is non-essential
feed palatability modifier
A positive palatant for dogs/cats is fat of (plant/animal) origin.
animal (NOT plant)
(T/F) Fat of animal origin is more expensive than carbohydrate.
True
What undesired effect is promoted by fat of animal origin?
weight gain
(T/F) Fat use is abundant and useful in ruminants.
False - limited inclusion but useful
Basis for lower limit of dietary fat is ____ to ___% dietary dry weight.
2 to 5
(T/F) Essential fats are polyunsaturated.
True
What does fat reduce in ruminant diets that makes it useful?
dustiness (improves diet + energy intake)
Fat in ruminant diets is reduced to ___ to ___% because of depression of what?
5 to 7
rumen microflora
How many carbons are present in essential fatty acids?
18 carbons or longer
Essential fatty acids are identified by their _____ length and position/number of ______.
chain length
double bonds
Saturated fatty acids have ____ double bond(s) and monounsaturated fatty acids have ___ double bond(s).
no
1
Term for “fatty acids with two or more double bonds”
polyunsaturated fatty acids (PUFAs)
The numbers after the delta symbol in chemical numbering system are positions of double bonds counting from and including the _______ of the fatty acid.
carboxyl carbon
What 2 numbering systems do nutritionists use for fats?
omega
methyl-end
The first number in chemical numbering systems indicate the number of _____. The number after the colon is number of _____.
carbons
double bonds
(T/F) Animals have desaturases that can introduce double bonds beyond 9 carbons from carboxyl end of fatty acid.
FALSE - do not have
Animal don’t have desaturases that can introduce double bonds beyond __ carbons from the _____ end.
9
carboxyl end
Term for “enzymes that introduce double bonds”
desaturases
A (cis/trans) isomer of desaturases is formed in animals.
cis (NOT trans)
Animals have physiological needs for ___ carbons and greater fatty acids with double bonds at the ___ or ___ positions.
18
n-3 (or w-3)
n-6 (or w-6)
(T/F) Animals can synthesize 18 carbons with greater fatty acids with double bonds at the n-3 and n-6 positions.
FALSE - cannot synthesize!
Animals can synthesize fatty acids up to ___ carbons in length.
16
(T/F) Animals can elongate essential and non-essential fatty acids from carboxyl end up to 24 carbons in length.
True
What enzymes do animals use to elongate fatty acids?
elongases
What are the 3 essential fatty acids?
linoleic acid
arachidonic acid
omega-3 series fatty acids
Which essential fatty acid is required in the largest amount in diet?
linoleic acid
Chemical number of Linoleic Acid
C18:2w6 or C18:2n6
Which essential fatty acid is in many vegetable oils and fat from animals eating vegetable sources?
linoleic acid
Arachidonic acid chemical number
20:4w6 or 20:4n6
Which essential nutrient is essential for cats? Why?
arachidonic acid
lack delta-6 desaturase
Which essential fatty acid is “conditionally-essential” nutrient in neonates of some species?
arachidonic acid
Why are cats distinguished as obligate carnivores?
arachidonic acid does not occur in plants
3 essential fatty acids in the omega-3 series
a-linolenic acid
docosahexaenoic acid
eicosapentaenoic
What omega-3 series essential fatty acid is NOT found in plants?
docosahexaenoic acid
(T/F) It’s unclear if a-linolenic acid is essential nutrient apart from being a precursor to DHA & EPA.
True
Which acid is obtained mostly from plants and a precursor to DHA & EPA?
a-linolenic acid
Chemical number for a-linolenic acid
18:3w3
DHA + EPA synthesis from ALA are (slow/fast) in adults and nearly ____ in cats
slow
absent
(T/F) DHA + EPA synthesis from ALA are (adequate/inadequate) in neonates.
inadequate
(T/F) a-linolenic acid, DHA, EPA, are added to milk replacers.
False: ALA not, DHA/EPA variably added
Docosahexaenoic acid chemical number
22:6w3 or 22:6n3
Which omega-3 series essential fatty acid is in mammalian brain/retina?
docosahexaenoic acid
The highest demand for docosahexaenoic acid is during what?
expansion of brain mass (young developing animals)
What two essential fatty acids are abundant in marine animals, especially oils?
DHA + EPA
Eicosapentaenoic acid chemical number
20:5w3 or 20:5n3
3 main body uses of essential fatty acids
- lipoprotein synthesis
- reproduction
- brain function (brain mass)
________ are 20-carbon bioactive compounds that are important for cell structure & signaling.
eicosanoids
3 essential fatty acid deficiencies
- linoleic acid def
- n-3 FA deficiency
- arachidonic acid def.
Signs of linoleic acid deficiency (growth, skin, blood, metabolism)
decreased growth
testicles degenerate & anestrus
scaly skin
anemia/fragile RBCs
decreased energy efficiency
2 signs of n-3 FA deficiency
brain & sensory system dysfunction
2 signs of arachidonic acid deficiency (growth + reproduction
reduced growth rate
queen cannot maintain pregnancy
For dogs & cats, ___ to ___% of dietary metabolizable energy is recommended for dietary fat.
25 - 35
“Low fat” diet = (</>) ___% ME.
< 25%
“Hight fat” diet = (</>) ___% ME.
> 35% ME
Steps in calculation of dietary fat content estimate (3)
- crude fat x physiological fuel value
- divide by ME content
- multiply by 100 (percentage)
w6 & w3 fatty acids compete as substrates for lipid mediators important to what 2 processes?
cellular synthesis
signaling pathways
w6 “family”
linoleic acid + arachidonic acid
w3 “family”
a-linoleic acid + EPA + DHA
(T/F) Some eicosanoid derivatives from arachidonic acid have different bioactivities than some eicosanoid derivatives from EPA.
True
(High/low) ratio of w6 to w3 fatty acids in diets is suboptimal.
both
What 3 ways is manipulation of w3:w6 ratio used for management of disease?
- fish oils w/ DHA + EPA lowers ratio
- low ratio = reduce inflammation (osteoarthritis diets)
- low ratio = modulate renal blood flow (chronic renal failure diets)
(T/F) Too much fish oil is detrimental.
True - loose stool, coagulopathy
