Module 1: Basics Of Animal Nutrition And Energy Flashcards
What is animal nutrition?
The science animals assimilate feeds and how the nutrients in the feeds are utilized for growth tissue repair and replacement and production of animal products
What are the two functions of animal nutrition?
- Maintenance Function: keeps animals healthy and alive through different nutrient needs
- Productive functions: reproductive growth (meat) lactation ( milk and eggs) reproduction
What are the 6 major reasons animal nutrition is important?
- product quantity
- product quality
- animal health - susceptibility to disease and speed of recovery
- reproductive success
- economics - cost of feed vs production
- environmental issues - GHG, methane, nitrogen and phosphorus and amonia production
What is a nutrient?
any chemical element or compound in the diet that is required for normal body functions
what classifies normal body functions?
- reproduction
- growth
- lactation
- maintenance of life processes
what are the 6 major classes of nutrients
- water
- proteins
- carbs
- fats/lipids
- minerals
- vitamins
what secondary functions do nutrients provide?
-supports cellular needs for an aqueous environment
- fuel energy
structeral constituents (skin, muscle and bone)
- metabolic regulation
What is the difference between essential and non-essential nutrients
essential - the body cant make in sufficient quantities so they must be eaten in the diet (amino acids)
non-essential - if the building blocks are avaliable - the body can make them
what is food
fuel for the body (foodstuffs)
what is feed
animal food(feedstuffs)
what is diet?
mixture of foodstuffs or feedstuffs that is consumed - can be mono or multu
what is ration?
specific amount or ratio, based on how much the animal needs and eats
what nutrient is most present in the body
water at 60%
protein 16%
fat 20%
minerals 4%
where are the two places that CH2O resides in the body
- circulating blood glucose
- glycogen in the liver/ skeletal muscle
what are the three ways nutrients is transformed
- digestion (digestive tract)
- absorbtion (digestive tract)
- metabolism (post absorbtion)
what is digestion of nutrients
physical (chewing, muscular contractions of GI) and chemical (hydrolysis) breakdown of complex molecules in feeds into simple molecules that can be absorbed by GI and utilized by tissues
what is the difference between gastric and fermentative digestion
Gastric - digestion facilitated by enzymes - utilized by monogastrics (pig, horse, chicken)
Fermentation - specialized compartment before stomach that holds micro organisms, bacteria, fungi and protozoa - ruminants ( cows, goats, sheep)
what are the organs in pig digestion
mouth - esophagus - stomach - small intestine - cecum and colon (large intestine
what are accessory organs in pig digestion
teeth, tongue salivary glands, liver, gall bladder and pancreas
what is secreted from salivary glands and what does it break down
salivary amaylase for starch breakdown as well as lubrication to move bolus down the throat
what is the purpose for somach contractions
muscular contractions to mechanically breakdown food
what is secreted in the stomach and what does it breakdown
HCL and pepsinogen(pro enzyme) which breakdown proteins
what does the small intestine secrete?? why?
pancreatic enzyme - part of pancreatic juice that also contains bicarbonate and lipase to act as a buffer to bring up pH level and neutralize stomach acid
what are the three sections of the small intestine
deudenum, illium and jejunum
what are brush border enzymes
maltase - bile thats produced in the liver and stored in the gall bladder - to emulsify fats
what is in the digestive tract of a chicken
mouth - no teeth, food is broken down by beak and crop
crop - food storage
proventriculus - stomach like, chemical digestion takes place
gizzard - mechanical breakdown
what are the 4 stomachs of a cow
rumen - largest and key to fermentation
reticulum - food enters
omasum - tissue leaves to squish feed
abomasum - chemical breakdown?
what type of environment is the microbiology of a rumen?
Anaerobic - cannot tolerate O2
what are the different groups in the microbiology? what is the largest?
bacteria - the largest
protozoa - second
fungi
archaea
can bacteria change with the change of feed?
yes
how does bacteria attach to feed particals
attaches to free-floating particles in rumen fluid, attach to rumen wall and attached to surface of the protozoa
how does protozoa and fungi attach?
attaches to larger feed particles
what is attachment to feed particles important
the enzymes responsible are on the walls of micro organisms - these enzymes must come into contact with the feed to break it down
why is fermentation important in digestion?
for the digestion of starch, cellulose and hemicellulose they cannot be digested by gastric juice - an animal can only get energy from these through fermentation
what produces volatile fatty acids
acetate, pronioate, and butyrate
these are major energy souces for ruminants
they are also important for microbial protein production
what is the absorbtion process and where does it take place
- passage of end products of digestion from the GIT into the body via the blood and lymph vessels
- site of absorbtion depends on digestive anatomy of the animal
what happens to amino acids
absorbed into the bloodstream - go to lymphatic system
what are villi and what do they do
on surface of small intestine projecting into the lumen
lined with microvilli to increase surface area for absorbtion
what are epithelial cells
secrete brush border enzymes to complete carbohydrate protein digestion
what are rumen papillea
on surface wall of the rumen wall
increase surface area - the higher energy the diet the more dense they are
they do not secrete enzymes
in non ruminants what is the major absorbtion site
small intestine
in ruminants what are the major sites of absorption
fore stomachs and small intestine
what is post absorptive metabolism
study of changes which nutrients undergo in different tissues after absorbtion ( what happens when they are absorbed into the lymphatic system
what are the two different processes
anabolic and catabolic
what is anabolism
the building of complex compounds from small molecules
- uses energy
- ex. protein synthesis
- typically uses energy from catabolism
catabolism
the breakdown of molecules into smaller units
glucose catabolism - results in release of energy, CO2 and H2O
- atp generation
General Functions of nutrients
- building and maintaining the body structure
- repairing warn out of injured tissues
- provide energy for various functions
- regulation of body processes
- fetal development
- production of products for human use such as milk, meat, eggs and wool
response to nutrients
draw the chart including
- deficiency, toxicity, reduced and high intakr and optimal range
- label the axis - functional/performance and nutrient intake
- label minimum requirement
will optimal range change?
changes depending on the animal
- physiological change
- weather change
what is the sequence of events in nutrient deficiency
nutrient deficiency
biochemical defect
functional defect
reduced performance
death
what makes a good diet
- must contain all the essential nutrients in the correct amounts and proportions
- must be palatable
- must be digestable
- must be economical
- must not contain any toxic substances or nutrient inhibitors
why would an animal not eat
- dry
- fed presentation
- taste or smell
what is energy
- not a nutrient
- what the cell is going to get out of CH2O, fats and protein
- water, vitamins and minerals do NOT supply energy
why care about energy
- nutrients to provide energy are expensive
- need to meet energy requirements
- least cost diet formula
what is the different between issues in developed vs non developed countries in terms of nutrition
developed - over supply of energy = obesity
non developed countries = diseases and illness
what is energy
the potential to do work
- the fuel of metabolism
what is a bomb calorimetry
measures the gross energy of a feedstuff
- heat released when carbs, lipids and proteins in feedstuff is oxidized
what is heat of combustion
total energy of feed gross
how do you determine gross energy with a bomb calerimeter
- a weighed amount of water is poured into the bucket
- 25-30 atmosphere of 02 to bomb so sample can be oxidized
-ignite the sample - measure increase of water temperature
- determine energy it would take to cause this increase
what is a correction factors to account for in bomb calorimitry
- metal bomb, the bucket will absorb some heat
- room temperature might change during test
what should you use to standardize the bomb
benzoic acid
what is a calorie
the amount of heat required to raise the temperature 1g of water by 1 C
what does europe use
joule
what is gross energy
the amount of heat released when a substance (feed is completely oxidized in bomb calorimeter)
- GE = heat of combustion
how much more Kcal/g energy does fat have
2.25X more energy
fat has 9.30
carb 4.20
protein 5.65
why are fats more energy dense
the length of C-H chains in the fats
- takes more O2 to oxidize those molecules
what are the limitations of gross energy
indicates very little about nutritional value of feed to an animal
- not 100% available to an animal
what is fecal energy
some feed energy is lost in feces due to incomplete digestion
single largest loss
what is apparent digestible energy
energy digestibility dependent on animal
- also contains microorganisms, old cells and enzymes
what is the order the digestibility falls
- 80% for pigs - monogastrics are generally higher then ruminants (more digestible diet
- 70% ruminants eating concentrate
- 50-60 % ruminants eating roughages
what is metabolizable energy
accounts for additional energy losses arising from absorption and metabolism of the feed
- urinary energy loss + gaseous energy loss( methane and CO2 and gill energy loss( amonia through gills)
what is urinary energy
- total collection of urine in digestibility trial
- metabolism crates (males
- bladder catheter in female
Determine the energy content of urine using bomb calorimetry, what is used
- 5-7 days
- measuring urea in animals
- uric acid in birds
what % od UE is lost
2-3% in pigs
4-5% in ruminants depending on feed type
what gases are considered energy losses
methane, hydrogen, hydrogen sulfide and carbon monoxide
how much % is generally lost from gases
1% monogastrics
3-15% in ruminants - the more concentrate consumed - less methane
the more forage the more methane
how much energy is created by gases
13.2 Mcal/kg
what is the SF6 tracer technique?
the use of a permeation tube with sulfer hexiflouride - measures respiration in the gaseous chamber
what is used for gase collection
collection canister, halter, capillary tubing placed in nose
draw it
what is net energy
accounts for energy lost as heat during digestion and metabolism
NE = ME - heat increment (HI)
what is a heat increment and how do you measure it
in heat production following a meal when the animal is in a thermo- neutral environemnt
- fast animal for 24 hours
- measure basal heat production
- give animal feed
- measure heat production
- measure the difference
components of heat increments
- work of digestion (5%)
- heat of fermentation (15%)
- nutrient metabolism (80%)
what environment wastes energy
Cold environment - the heat increment goes up in the winter to generate heat
what are the maintenance components of net energy
- basal metabolism
- thermoregulation
- voluntary activity associated with maintenance
what are the production components of net energy
- growth
- fat deposition
- reproductive products
- milk
- eggs
what are some factors effecting heat incriments
- diet digestibility ( as digestibility increases heat increment decreases and swap)
- level of feeding ( more feed more heat becasue of work to digest )
- diet compositions ( forages vs concentrates, forages are harder to digest so heat is higher)
- nutrient utilization (catabolism vs retention as animal products - in catabolism atp and heat increases)
- amino acid balance (break down inbalances = heat increase)
- frequency of feeding ( more frequent feeding has smaller heat increment and swap)
what is direct calorimetry
heat production measured directly
- insulated chamber
- put animal in and fast them
- feed animal and measure heat given off
- heat loss measured as rise in temperature of absorbing medium in insulated chamber
- urine collectors to account for urinary loss
what is indirect calorimetry
- use gaseous exchange (o2 in and out) to estimate heat loss
what are the two different types of indirect circuits
closed circuit
- totally enclosed system
- oxygen supplied
-no air leaving
- measuring change in weight of CO2 absorber
Open circuit
- let in atmospheric air
what ever air is produced is blown out
co2 is measured as air is transferred out
what are the advantages to a net energy system
accounts for metabolic cost of nutrient metabolism
allows a better prediction of animal performance based on diet formulation
what are disadvantages of net energy system
expensive and time consuming
what are the most common diet formulations for pigs, poultry and ruminants
Pigs - NE ( urine, gas and HI too low)
poultry - ME (fecal and urine are excreted together = ignores gaseous and heat increment)
Ruminants - NE - gaseous and heat increment to large of loss
what is TDN
total digestible nutrients used to express energy content of feed before bomb calorimetry
- uses values from proximate analysis
- roughly compared to DE
- the higher the TDN the higher energy the feed contains
what factors can affect TDN
- dry matter content of feed = nutrients contained in the feed besides water (lipids, carbs and proteins) the higher the dry matter content the higher the TDN
- digestibility of dry matter - feed intake effects = higher digestibility the higher the TDN
-the more the animal eats the higher the TDN BUT if the animal over consumes digestibility and TDN goes down - amount of fat = the more fat you have in the feed the higher the TDN
- species fed - ruminents have higher TDN cause of fermiative digestion
- monogastrics with digest concentrates and have higher TDN then ruminants
Energy is the most important nutrient for animals T/F
False, energy is not a nutrient
Rumen papillae produce important enzymes that facilitate fermentation digestion in the rumen T/F
papillae do not secrete enzymes they are responsible for absorbing fatty acids
- fermentation is done by bacteria
gastric digestion of carbs in pig yields is mostly
glucose
the most importan source of energy for ruminants that is derived from the GIT is
Volatile fatty acids
- acetate, propionate and butyrate
is the mechanism of nutrient absorption that requires the expenditure of energy
passive diffusion or facilitated diffusion
gross energy - fecal energy- gaseous energy - urinary energy =
metabolizable energy
maintenance energy + productive energy =
Net Energy
