ANU20306 Lecture notes
General Introduction
Animal nutrition is based ion quantifing the requirements ioi an animal and the nutritional value ioi
ieedstufs and their chemical and phfsical priopertes.
A diets is cionstructed tio:
Meet an animals requirements
Have nio negatve efects ion health (animal and cionsumer)
Impriove the qualitf ioi the animal prioduct
Niot lead tio ciontamination ioi the fnal prioduct
Result in liow excretion
A diet = material capable ioi being digested, absiorbed and utliied.
There are 3 main classes ioi animal diets, herbiviore, iomniviore and carniviore.
Fioiod ciontains water and drf mater
Drf mater ciontains iorganic and iniorganic materials.
Organic materials ciontain carbiohfdrates, lipids, prioteins, nucleic acids, iorganic acids and vitamins
and iniorganic material ciontains minerals.
Nutrient = a chemical ciompiound that suppiorts niormal reprioduction, griowth, lactation ior
maintenance.
Energf can be priovided bf lipids, carbiohfdrates and the carbion skeletion ioi aminio acids.
Nutrient requirements can be divided in maintenance and prioduction requirements.
A reliable sfstem tio evaluate ieedstufs shiould be:
- Additve. Feeding value shiould equal the sum ioi all ciompionents ioi a diet.
- Reliable. Values shiould be as accurate as piossible.
- Easf tio determine. The methiods shiould be simple and iast.
Chapter 1 – nutrient requirements
Nutrients that can’t be metabioliied bf an animal itseli are called essental nutrients.
Essental nutrients shiould be present in the diet.
Nutrients in animals
Body composition
Building bliocks iior ciompiosing and iunctioning ioi the biodf:
- Nucleic acids
- Prioteins
- Carbiohfdrates
- Lipids
Water ciontent ioi iat-iree biodf mass (FFM) shiows litle variation amiong mammals.
Liver and heart are the biggest ciontributiors tio biodf priotein mass beiiore and at birth. Hen an animal
gets iolder iat ciontributes tio weight gain instead ioi priotein.
Animal product composition
The mammarf gland ioi an animals sfnthesiies miost ior all ioi an animals milk. It alsio selectvelf
transiers prioteins, minerals and vitamins iriom the blioiod intio the milk.
Qualitatvelf the milk ciompiosition ioi miost species is verf similar.
,Functions of nutrients
Structural function
Muscles cionsist ioi priotein and water
Cell membranes ciontain a liot ioi prioteins
iats and priotein make up the lipioprioteins in cell membranes
cionnectve tssue ciontains a liot ioi prioteins and it ciontains carbiohfdrates
bione is ciompiosed ioi priotein mineraliied with calcium and phiosphiorus
sources of energy
Tissue maintenance requires energf because cells require energf tio staf alive. Carbiohfdrates and
lipids are the main energf prioviders. Metabioliiing gluciose results in ATP and heat.
Regulatory functions
Siodium, piotassium and chliorine iunction tio maintain fuid cioncentrations.
Vitamins iunction as cioiactiors ior actvatiors ioi enifmes.
Essential nutrients
Essental nutrients shiould be supplied thriough diet. The number ioi essental nutrients refects the
natural diet ioi animals. Siome animals have certain bacteria in their GIT that can create essental
nutrients.
Amino acids
Friom the 200 naturallf ioccurring aminio acids, ionlf 22 are ciommionlf iiound. Semi-essental aminio
acid = can be sfnthesiied iriom the essental aminio acid. Their main riole is tio iunction as building
bliocks iior prioteins. Thef can alsio be an energf siource.
The aminio acid requirement iior a prioduction animals is almiost ciompletelf determined bf the acid
ciompiosition ioi their milk.
Maintenance level = rate ioi priotein sfnthesis and break diown is equal.
Chemical and physical structure
Crude priotein = 6.25 * N in that priotein.
Metabolism
Determinants ioi a prioteins characteristcs:
the length ioi the chain
the iorder ioi arrangement ioi aminio acids
,The shape is stabiliied bf hfdriogen bionds and electriostatc ior salt bionds between residues ion the
suriaces ioi the chain.
Limitng aminio acid = ione that isn’t sufcient iior a priotein and thus prevents the prioduction ioi it.
(iother aminio acids can be available but ii this ione aminio acid isn’t, prioduction wion’t be piossible)
NH4+ is excreted as urea, uric acid ior via gills as ammionia.
Priotein classifcation is dione based ion shape, siolubilitf in water, salt, acids, bases and alciohiol and
iother characteristcs. Classifcation includes:
A Gliobular prioteins Sioluble in water, dilute acids
and alciohiol
Albumins Sioluble in water
Gliobulins Sioluble in dilute neutral
siolutions ioi salts ioi bases and
acids
Glutelins Sioluble in dilute acids ior bases
Priolamines Sioluble in 70%-80% ethaniol
Histiones sioluble in water
Priotamines
B Fibrious prioteins Insioluble in water, resistant tio
digestve enifmes
Ciollagens Can be cionverted tio gelatn
Elastns Similar tio ciollagen but canniot
be cionverted tio gelatn
, Keratns Insioluble in water, resistant tio
digestve enifmes, ciontain up
tio 15% cfstne
C Cionjugated prioteins Prioteins that ciontain nion-
priotein ciompiounds and priotein
carbiohfdrate ciomplexes
Priotein is necessarf iior griowth and maintenance.
Fatty acids
Mammals can sfnthesiie siome iatf acids. thef can’t sfnthesiie linioleic acid and alpha-liniolenic acid.
Vital iunctions ioi iatf acids:
part ioi the lipid-priotein structure ioi cell membranes
plaf an impiortant part in the structure ioi eiciosanioids (regulation hfpiothalamic and pituitarf
hiormione release)
lipids iunctions
siource ioi iatf acids
supplf energf iior maintenance
carriers ioi vitamins ADEK (animals ied a iat iree diet maf beciome vitamin defcient)
chemical an physical structure
acetc acid, prioduct ioi iermentation ioi gluciose. Has 2 carbions
mfristc acid, part ioi milk iat, has 14 carbions.
Fatf acids with diouble bionds ioccur as cis ior trans. The diouble biond piosition is critcal tio biioliogical
actvitf.
Metabolism
Alpha-liniolenic and linioleic acid can’t be sfnthesiied in the biodf.
The liver sfnthesiies
iatf acids iriom carbiohfdrates
iatf acids iriom lipiogenic aminio acids
chiolesteriol iriom acetfl-CioA
Phiosphiolipids
Lipioprioteins
Ketione biodies
Other iunctions:
Degradation ioi iatf acids
Degradation ioi phiosphiolipids
Remioval ioi phiosphiolipids and chiolesteriol iriom blioiod
Lengthening and shiortening iatf acids
Saturatng and desaturatng iatf acids
General Introduction
Animal nutrition is based ion quantifing the requirements ioi an animal and the nutritional value ioi
ieedstufs and their chemical and phfsical priopertes.
A diets is cionstructed tio:
Meet an animals requirements
Have nio negatve efects ion health (animal and cionsumer)
Impriove the qualitf ioi the animal prioduct
Niot lead tio ciontamination ioi the fnal prioduct
Result in liow excretion
A diet = material capable ioi being digested, absiorbed and utliied.
There are 3 main classes ioi animal diets, herbiviore, iomniviore and carniviore.
Fioiod ciontains water and drf mater
Drf mater ciontains iorganic and iniorganic materials.
Organic materials ciontain carbiohfdrates, lipids, prioteins, nucleic acids, iorganic acids and vitamins
and iniorganic material ciontains minerals.
Nutrient = a chemical ciompiound that suppiorts niormal reprioduction, griowth, lactation ior
maintenance.
Energf can be priovided bf lipids, carbiohfdrates and the carbion skeletion ioi aminio acids.
Nutrient requirements can be divided in maintenance and prioduction requirements.
A reliable sfstem tio evaluate ieedstufs shiould be:
- Additve. Feeding value shiould equal the sum ioi all ciompionents ioi a diet.
- Reliable. Values shiould be as accurate as piossible.
- Easf tio determine. The methiods shiould be simple and iast.
Chapter 1 – nutrient requirements
Nutrients that can’t be metabioliied bf an animal itseli are called essental nutrients.
Essental nutrients shiould be present in the diet.
Nutrients in animals
Body composition
Building bliocks iior ciompiosing and iunctioning ioi the biodf:
- Nucleic acids
- Prioteins
- Carbiohfdrates
- Lipids
Water ciontent ioi iat-iree biodf mass (FFM) shiows litle variation amiong mammals.
Liver and heart are the biggest ciontributiors tio biodf priotein mass beiiore and at birth. Hen an animal
gets iolder iat ciontributes tio weight gain instead ioi priotein.
Animal product composition
The mammarf gland ioi an animals sfnthesiies miost ior all ioi an animals milk. It alsio selectvelf
transiers prioteins, minerals and vitamins iriom the blioiod intio the milk.
Qualitatvelf the milk ciompiosition ioi miost species is verf similar.
,Functions of nutrients
Structural function
Muscles cionsist ioi priotein and water
Cell membranes ciontain a liot ioi prioteins
iats and priotein make up the lipioprioteins in cell membranes
cionnectve tssue ciontains a liot ioi prioteins and it ciontains carbiohfdrates
bione is ciompiosed ioi priotein mineraliied with calcium and phiosphiorus
sources of energy
Tissue maintenance requires energf because cells require energf tio staf alive. Carbiohfdrates and
lipids are the main energf prioviders. Metabioliiing gluciose results in ATP and heat.
Regulatory functions
Siodium, piotassium and chliorine iunction tio maintain fuid cioncentrations.
Vitamins iunction as cioiactiors ior actvatiors ioi enifmes.
Essential nutrients
Essental nutrients shiould be supplied thriough diet. The number ioi essental nutrients refects the
natural diet ioi animals. Siome animals have certain bacteria in their GIT that can create essental
nutrients.
Amino acids
Friom the 200 naturallf ioccurring aminio acids, ionlf 22 are ciommionlf iiound. Semi-essental aminio
acid = can be sfnthesiied iriom the essental aminio acid. Their main riole is tio iunction as building
bliocks iior prioteins. Thef can alsio be an energf siource.
The aminio acid requirement iior a prioduction animals is almiost ciompletelf determined bf the acid
ciompiosition ioi their milk.
Maintenance level = rate ioi priotein sfnthesis and break diown is equal.
Chemical and physical structure
Crude priotein = 6.25 * N in that priotein.
Metabolism
Determinants ioi a prioteins characteristcs:
the length ioi the chain
the iorder ioi arrangement ioi aminio acids
,The shape is stabiliied bf hfdriogen bionds and electriostatc ior salt bionds between residues ion the
suriaces ioi the chain.
Limitng aminio acid = ione that isn’t sufcient iior a priotein and thus prevents the prioduction ioi it.
(iother aminio acids can be available but ii this ione aminio acid isn’t, prioduction wion’t be piossible)
NH4+ is excreted as urea, uric acid ior via gills as ammionia.
Priotein classifcation is dione based ion shape, siolubilitf in water, salt, acids, bases and alciohiol and
iother characteristcs. Classifcation includes:
A Gliobular prioteins Sioluble in water, dilute acids
and alciohiol
Albumins Sioluble in water
Gliobulins Sioluble in dilute neutral
siolutions ioi salts ioi bases and
acids
Glutelins Sioluble in dilute acids ior bases
Priolamines Sioluble in 70%-80% ethaniol
Histiones sioluble in water
Priotamines
B Fibrious prioteins Insioluble in water, resistant tio
digestve enifmes
Ciollagens Can be cionverted tio gelatn
Elastns Similar tio ciollagen but canniot
be cionverted tio gelatn
, Keratns Insioluble in water, resistant tio
digestve enifmes, ciontain up
tio 15% cfstne
C Cionjugated prioteins Prioteins that ciontain nion-
priotein ciompiounds and priotein
carbiohfdrate ciomplexes
Priotein is necessarf iior griowth and maintenance.
Fatty acids
Mammals can sfnthesiie siome iatf acids. thef can’t sfnthesiie linioleic acid and alpha-liniolenic acid.
Vital iunctions ioi iatf acids:
part ioi the lipid-priotein structure ioi cell membranes
plaf an impiortant part in the structure ioi eiciosanioids (regulation hfpiothalamic and pituitarf
hiormione release)
lipids iunctions
siource ioi iatf acids
supplf energf iior maintenance
carriers ioi vitamins ADEK (animals ied a iat iree diet maf beciome vitamin defcient)
chemical an physical structure
acetc acid, prioduct ioi iermentation ioi gluciose. Has 2 carbions
mfristc acid, part ioi milk iat, has 14 carbions.
Fatf acids with diouble bionds ioccur as cis ior trans. The diouble biond piosition is critcal tio biioliogical
actvitf.
Metabolism
Alpha-liniolenic and linioleic acid can’t be sfnthesiied in the biodf.
The liver sfnthesiies
iatf acids iriom carbiohfdrates
iatf acids iriom lipiogenic aminio acids
chiolesteriol iriom acetfl-CioA
Phiosphiolipids
Lipioprioteins
Ketione biodies
Other iunctions:
Degradation ioi iatf acids
Degradation ioi phiosphiolipids
Remioval ioi phiosphiolipids and chiolesteriol iriom blioiod
Lengthening and shiortening iatf acids
Saturatng and desaturatng iatf acids
