Introduction, properties and functions of nutrients Flashcards
Define nutrition
science that interprets the interaction of nutrients and other substances in food that influence the maintenance, growth, development, reproduction and health of animals
what does nutrition include
- food/feed intake (+ feeding behavior)
- digestion, absorption, assimilation, metabolism of nutrients
- excretion of metabolites
define nutrient
compounds in food essential for life and health
function of nutrients
- provide energy for physiological processes
- building blocks for repair and growth
what are the origins of most nutrients
plant origin (can be direct or indirect)
what is the importance of animal nutrition
most animal feed is unsuitable for human consumption
- pastures: areas not adequate for agriculture
- recycling: distillers grains, corn screenings
transformation to high quality food (suitable for humans)
3 steps of nutrient transformation
- food intake
- digestion, absorption, assimilation and metabolism of nutrients
- excretion of metabolites
metabolism
comprises all chemical reactions in living organisms to generate energy, building blocks and elimination of waste at a cellular level
catabolism
degradation/ breakdown compounds/ nutrients = energy/ building blocks
is catabolism exergonic or endergonic
exergonic reactions (release energy, including heat)
define anabolism
constructs molecules from smaller units
is anabolism exergonic or endergonic
endergonic
does anabolism use ATP
yes, endergonic reactions use energy/ATP
what does anabolism do
builds tissues = growth
what is anabolism powered by
catabolism
what contributes to diet formulation in practice
animal requirement for nutrients, proxies and feed composition (feed analysis)
what do nutritional requirements depend on
each individual animal’s specific and unique genome, its environment and its stage in life
how much of the diet is allotted for energy
80% - is a major nutritional need
how much of the diet is allotted for protein
<20%
how are nutritional requirements determined
under controlled environment/ ideal conditions
examples of how nutritional requirements can be determined under controlled environment/ ideal conditions
resp/ calorimetry chambers
what are some factors that can cause variability in nutritional requirements
variability due to stress, genetics, breeds, individual uses (ex. residual intake, methane production)
what is precision livestock nutrition/feeding (precision farming)
precisely match nutrient supply to requirements to prevent over or under supply
what are 2 methods of applied nutrition
- box/pearson square method
- linear programming
describe the box/ pearson square method
2 ingredient mixtures or single nutrient balance (TDN, CP, ME, vit, min)
describe how linear programming can be used in applied nutrition
multiple nutrients simultaneously for least cost formulation (most common) or mathematical modelling
what is it called when nutrient requirements exceed nutrient intake
deficiency
what is it called when nutrient intake exceeds the nutrient requirements
toxicity
what are some factors related to the animal that contribute to nutritional balance
species, sex, age, physiological status/ stage, breed, health
what are some factors related to the environment that contribute to nutritional balance
temperature (TH index), feed quality and availability, water, shade, management practices
what are some health problems that contribute to nutritional imbalances
obesity, type II diabetes, deficiencies
what environmental impacts (pollution) can contribute to nutritional imbalance
excess nitrogen
what is the highest cost in animal production
feed
what is the most common nutritional disorder in dogs, cats and horses
obesity
what can cause feed toxicities
environmental contaminants, bacterial contaminants, fungal contaminants, mycotoxins, plant toxins, weed seeds, animal toxins, undeclared additives
what are the most common nutritional problems
mineral and vitamin deficiencies
what are the digestive processes of the gastrointestinal tract
ingestion, propulsion, digestion (mostly small intestine, can be mechanical or chemical), absorption, excretion
where does most nutrient absorption take place
microvilli in small intestine
where does most water and electrolyte absorption take place
large intestine
where do absorbed nutrients go
circulation then liver
name the animals that are monograstric
dogs, cats, pigs, humans
which animals are ruminants
cattle, sheep, goats, camelids (kinda)
which animal is a pseudorum
camelids
name 2 hindgut fermenters
rabbits, horse
name some animals that have avian digestive system
chicken, turkey, duck
what is considered the foregut in monogastrics
salivary glands, mouth, pharynx, esophagus, stomach and liver
what is the role of the foregut in monogastric species
ingestion, mastication, digestion
what is included in the midgut of monogastric species
small intestine (duodenum, jejunum, illeum) and pancreas
what is the function of the midgut in monogastric species
digestion and absorbtion
what is considered the hindgut in monogastric species
colon, cecum, anus
what is the function of the hindgut in monogastric species
reabsorption, storage, excretion
dogs and cats are what kind of monogastric animals
monogastric carnivores with limited post-gastric fermentation
describe mastication in dogs and cats
large canines and incisors for tearing/ shearing in vertical plane but little/ no chewing activity
what kind of stomach do dogs and cats have
simple stomach, not capable of digesting high fibre diets (forage; plants)
describe the intestinal tract in dogs and cats
short compared to other species
where does most absorption take place
jejunum
what foods do dogs and cats have limited ability in digesting
grains and fruits
pigs are what kind of monogatric animal
monogastric omnivore
what kind of stomach do pigs have
simple stomach
can pigs utilize fibre, why?
Yes in moderate amounds because it can be fermented in their cecum and colon
what is special about the cecum and colon in pigs
have sacculations/ haustra: longitudinal muscle bands for prolonged digesta retention
what are the functions of the avian foregut
ingestion, storage, digestion, maceration
what are the components of the avian foregut
salivary glands, pharynx, beak, esophagus, crop, proventriculus, gizzard, liver
what are the functions of the avian midgut
digestion and absorption
what are the components of the avian midgut
liver, small intestine
what are the functions of the avian hindgut
reabsorption, storage, excretion
what are the components of the avian hindgut
cecum, colon, cloaca
what is the avian digestive system classified as
modified monogastric
what replaces the lips and teeth in a bird
beak - no chewing
function of the crop
stores and softens feed prior to entering stomach
does the crop aid in digestion
no (negligibly)
the crop is an enlarged area of the ___
esophagus
the proventriculus is a ______ part of the ______
…is a glandular part of the stomach
function of the proventriculus
secretes digestive juices (may store food in carnivore avian species)
the gizzard is a _____ part of the ______
… muscular part of the stomach
function of the gizzard
grinding and mixing food
function of the koilin membrane in the gizzard
creates an abrasive surface
2 things inside the gizzard to help with the grinding and mixing of food
grit (small stones) and koilin membrane
function of the branched cecum in birds
some post-gastric fermentation
function of the cloaca
receives fecal and urinary waste
which tracts is the cloaca the common opening for
common chamber for opening of GI, urinary and reproductive tracts
do avian species create uric acid or urea
uric acid (insoluble)
What are the components of the ruminant foregut
salivary glands, mouth, pharynx, esophagus, reticulum, rumen, omasum, abomasum, liver
what is the function of the ruminant foregut?
ingestion, mastication, fermentation, digestion
what are the components of the ruminant midgut
duodenum, pancreas, jejunum, illeum
what are the functions of the ruminant midgut
digestion and absorption
what are the functions of the ruminant hindgut
resorption, storage, excretion
3 examples of ruminants
cattle, sheep, goats
what is fermentation pre or post gastric in ruminants
pregastric
what is different about the mastication in ruminants
have specialized premolars and molars (upper dental pad in cattle) for shearing and grinding
how many times do cows chew their cuds a day
~50,000 times
what is the importance of rumination
break down forage into small particles, stimulate salivation and rumen contractions
what is the reticulo-rumen
large anaerobic fermentation chamber (micro-org)
what compounds are contained within the reticulo-rumen
volatile fatty acids (VFA) (acetate, propionate, butyrate) + CO2 and CH4 (belching/eructation)
what is the omasum lined with
folds (leaves)
what is the function of the omasum
VFA/H2O absorption, small feed particles
what is the abomasum also known as
true glandular stomach
what is the function of the abomasum
secretes HCL and enzymes (lysozymes) to aid nutrient breakdown (plot)
is there alot of fermentation taking place in the cecum and colon of ruminants
no, limited
true/false: ruminants begin life as monogastric
true! calves feed on milk (reticular/ oesophageal groove)
what kind of ruminant are camelids
pseudo-ruminants
what do pseudo ruminants do better than regular ruminants
ability to extract nutrients and water from feedstuffs better
what kind of environments do pseudo-ruminants typically live?
survive in harsh, dry, nutrient poor enviro
how many compartments do pseudo-ruminants have for feeding and processing
3 (C1-3)
describe C1 in pseudo-ruminants
largest portion (cranial and caudal sac)
describe C2 in pseudo-ruminants
smallest portion, glandular cells, similar function to glandular saccules
describe C3 in pseudo-ruminants
tubular structure, highly absorptive
describe the cranial vs caudal portions of C3 in pseudo ruminants
cranial 80%: folds with glandular epithelium (sim. to gland saccules) +
terminal 20%: gastric glands releasing HCL and proteases
what is considered the true stomach in psedo-ruminants
the caudal 20% of C3
which compartments of fermentation are responsible for rhythmic contractions with eructation (belching) and regurgitation
C1 and C2
which components of the GI are considered the foregut in hindgut fermenters
mouth, pharynx, esophagus, stomach, liver, salivary glands
what are the functions of the foregut in hindgut fermenters
ingestion, mastication, digestion
components of the midgut in hindgut fermenters
duodenum, jejunum, illeum, pancreas
function of the midgut in hindgut fermenters
digestion, absorption
functions of the hindgut in hindgut fermenters
fermentation, reabsorption, storage, excretion
components of the hindgut in hindgut fermenters
cecum, colon, anus
what kind of monogastric herbivores are equids and rabbits
monogastric herbivores with extensive post-gastric fermentation
describe the stomachs in hindgut fermenters
simple stomach incapable of utilization of forage based (high fibre) diets
describe the cecum and colon in hindgut fermenters
voluminous-sacculated (haustra)
describe the function of the cecum and colon in hindgut fermenters
extensive fibre fermentation - VFA absorption
is the cecum and colon of hindgut fermenters good at absorbing microbial protein
no
T/F: hidngut fermentation is less efficient than in ruminants
true
do horses possess a gall bladder
no, associated to meal frequency (many small meals
what species is the margo plicatus present in
horse
where is the margo plicatus located
between the non-glandular and glandular stomach
how is feces separated in rabbits
peristaltic contractions separate fiber via size and density into two faeces
describe the components of hard faeces of rabits
indigestible fiber
what are cecotropes
soft faeces: re-injested adn re-digested (bacterial prot and vitamins from caecum)
what does the presence of soft faces indicate
disease, stress or nutritional issue