Principles of Nutrition (1-8) Flashcards
this is the cornerstone of animal productivity, health & welfare; single largest component of costs for animal production (accounts for 80% of production costs)
nutrition
deficiency of this mineral can cause swayback in mid to late pregnancy ewes
copper (Cu)
deficiency of these two vitamins/minerals can cause white muscle disease
selenium (Se) and vitamin E
this is plant cell wall material, fibre insoluble in neutral detergent, residue contains CW materials = lignin + cellulose + hemicellulose
neutral detergent fibre (NDF)
this is fibre that is insoluble in acid detergent, residue contains CW materials = lignin + cellulose
acid detergent fibre (ADF)
DM stands for…
dry matter
OM stands for..
organic matter
CP stands for..
crude protein
these are the cornerstone of farm animal diets, farm animals depend on it for maintenance and production
plant & plant products
this is a non-CHO monomer, negatively correlated to digestibility (gives plant strength but highly resistant to chemical and microbial degradation); hay and straw are rich in it
lignin
this is a key factor in nutritional value of forages; as it increases the structural material increases and the nutritional value reduces
maturity
these are associated with cell contents and constitute storage CHO of plant
non structural carbohydrates
these are the principle non-structural CHOs
fructan and starch
this is the major storage of CHO of temperate grasses; soluble in H2O
fructan
NSC stands for..
non-structural carbohydrate
lower temperatures will result in (increased or decreased?) non-structural carbohydrates (NSC)
increased
increased light intensity will result in (increased or decreased?) non-structural carbohydrates (NSC)
increased
decreased water stress will result in (increased or decreased?) non-structural carbohydrates (NSC)
increased
increased fertilizer application will result in (increased or decreased?) non-structural carbohydrates (NSC)
decreased
this is a major source of NSC found in many plants (cereal grains, forage legumes, roots & tubers)
starch
what is neutral detergent fibre (NDF) consist of
hemicellulose + cellulose + lignin
what is acid detergent fibre (ADF) consist of
cellulose + lignin
what does NSC stand for?
non-structural carbohydrate
what is the NSC fraction composed of?
Starch + WSC
what is the WSC fraction composed?
fructan + simple sugars
this is the primary UK agricultural crop and accounts for approximately 70% of UK agricultural land
grass/grasslands
grass makes up this percent of sheep diet
90-95%
grass makes up this percent of beef cattle diet
80-85%
grass makes up this percent of dairy cattle diet
60-65%
grass makes up this percent of horses diet
80-90%
two overall types of grasslands
natural and cultivated
two types of cultivated grasslands
permanent and rotational
what is the approximate dry matter percentage of young grass
15-20%
what is the approximate dry matter percentage of mature grass
25-50%
what is the metabolizable energy of young grass (MJ/kg DM)
11.5-12.5
what is the metabolizable energy of mature grass (MJ/kg DM)
9.5-10.5
what is the crude protein of young grass (g/kg DM)
150-250
what is the crude protein of mature grass (g/kg DM)
50-130
this type of grassland is rough grazing; uncultivated/unimproved; largely grazed by sheep - maintenance diet only
natural grasslands
this type of cultivated grassland is improved pasture more than 5 years old; grass is more palatable and greater nutritional value - forms backbone of livestock industry in UK
permanent pasture
this type of cultivated grassland is common in mixed farms; sown every few years, used for grazing and/or conservation, less than 5 years old
rotational pasture
which is more palatable and more greater nutritive value; permanent, rotational or natural grassland?
rotational pastures
what is the crude protein of clover (g/kg DM)
170-250
this legume can be red or white, higher protein than grasses, higher in many minerals than grasses
clovers
what are two associated problems with clover
bloat and phytoestrogens (red)
this legume is grazed or conserved, has higher protein and minerals than mature grasses, not grazed in UK
Lucerne
what are 6 factors affecting grass growth
- time of year
- environment
- soil status
- grass species
- general management
- cutting & grazing strategies
for acidic soils, you can use this to increase pH
lime
for alkali soils, you can use this to reduce pH
sulphur
what 5 things does general management of grasslands involve?
- fertilizing
- mechanical treatment
- drainage
- grazing
- conserving
what are the 3 important organic components of fertilizer?
- nitrogen (N)
- phosphorous (P)
- Potassium (K)
how often is fertilizer applied during season until August
3-4 weeks
this is essential for sward productivity and to prevent sward damage
drainage
what are 4 grazing strategies for grasslands
- continuous stocking
- rotational grazing
- mixed or alternate grazing
- integrated conservation and grazing
this type of grazing strategy allows uncontrolled grazing of pastures, variable or set stocking rate, often grazed for whole grazing season (or year round)
continuous
this grazing strategy involves sub-dividing areas into series of paddocks/fields and grazing them in sequence followed by a period of rest
rotational grazing
this type of grazing strategy is simple and commonly used; involves mixing animal species or alternating the species; dilutes parasite infestation
mixed or alternate
this type of grazing strategy involves conservation rests for the field from livestock/exploits patterns of grass growth; grazed in sequence, common in 1-2-3 (1/3:2/3 system)
integrated conservation with grazing
what type of grass/nutritional value do dairy cows need
young, great nutritional value
what type of grass do beef cows need
more mature grass
what type of grass do sheep need
short grass length
what type of grass do horses need?
lower nutritional value
what is the most important factor in nutritional value of grass
stage of growth
when is grass growth typically most productive in the UK?
April-June
what is the single most important factor that determines the nutritional value of grass?
stage of growth
why does nutritional value of grass decrease with growth?
contains more lignin
what are 2 main methods of forage conservation
- remove moisture for aerobic storage
- acidification in an aerobic environment
this is a conserved forage with plant material dried to moisture content of ~15%, it is a stable product resistant to microbial degradation and predominately made from grass in the UK
hay
what 5 factors influence the nutritional quality of hay
- cutting date (stage of growth)
- herbage species
- soil type
- environmental factors during cutting/drying
- changes during storage
what 3 unfavorable outcomes can extended drying of hay lead to
respirable losses of WSC, hydrolysis of plant proteins, growth of bacteria/fungi
this type of drying for artificial dehydrated forage has minimal effect on nutritional quality but is very expensive
high temperature (HT) drying
this conserved forage is conserved through fermentation of forage crops with a relatively low level of DM (55% moisture) and stored under anaerobic conditions; herbage is cut at an early stage of growth
silage
why is lactic acid important in silage
lowers pH to inhibit plant enzyme activity and prevent growth of spoilage organisms
what are 3 associated problems with hay
mould, mycotoxins, dust
what are 3 associated problems with silage
- poor fermentation
- clostridia/listeriosis
- pH too low or high
what part of the crop is fermented into lactic acid be lactobacilli bacteria under anaerobic conditions to make silage
water soluble carbohydrates (WSC)
what pH do you want your silage to be at?
3.8-4.8
at what temperature does the stability of silage increase at?
below 10 C
this is a fermented crop that is cut at a more mature stage, with a higher DM and pH
haylage
what is the ideal pH range for haylage
4.5-5.5
these are produced by graminaceous plants grown for their seeds; less variable composition than forages; main component is starch
cereal grains
these concentrates are low in protein quality, low in calcium, high in phosphorus (poor Ca:P ratio)
cereal grains
what are 2 simple mechanical processing options for cereal grains
rolling and grinding
what are 2 more sophisticated techniques used to process cereal grains
micronization and extrusion
3 reasons why cereal grains are processed
- to increase its nutritional value
- better rumen degradability (cattle and sheep)
- improves small intestinal digestibility (horses, pigs and poultry)
these are co-products of brewing and distilling industries (used in ruminant diets); high in fibre and P, low in Ca
brewers and distillers grains
these are historically key supplementary feeds that have high digestibility, high sugar, and low CP (turnips, swedes, mangel, carrots, parsnips, etc)
roots
this is the residue of sugar beet after the extraction of sucrose; can be dried, shredded or pelleted; high digestible fibre content, moderate CP level, high Ca
sugar beet pulp
residue after hexane extraction of oil from oilseeds are referred to as these
meals
which oilseed meal is most commonly used
soya bean meal
this is the proportion of food not excreted in feces (this the proportion assumed to be absorbed by the animal)
digestibility
what is the coefficient / percentage equation for digestibility?
(intake - output) / intake (x100 for percentage)
what two ways can digestibility be classified?
apparent or true
this classification of digestibility is where the digestibility of feed is determined by measuring the quantity of feed consumed and the quantity of feces produced
apparent digestibility (AD)
what is the most commonly used measure of digestibility
apparent digestibility
this classification of digestibility takes into account that feces also contain undegraded microbial biomass and non-dietary or endogenous fraction
true digestibility
what is the equation for dry matter digestibility (DMD)?
(DM in with feed - DM out with feces) / DM in with feed
A cow eats 20 kg silage with DM of 250 g/kg
this cow excretes 10 kg of feces with DM of 200 g/kg
what is the DMD of this silage?
60%
what is the equation for organic matter digestibility (OMD)
(OM in with feed - OM out with feces) / OM in with feed
this is a commonly used term of the measure of energy value of a food
digestible organic matter in the dry matter digestibility (DOMD)
what is the equation for DOMD (digestible organic matter in the dry matter digestibility)?
(OM in with feed - OM out with feces) / DM in with feed
digestibility studies consist of these two phases
adaptation phase and collection phase
name two things that can be used as internal markers for measuring digestibility in vivo
lignin and silica (acid-insoluble-ash)
name 5 factors that affect feed digestibility
- food composition
- food processing
- level of feeding
- ration composition
- animals
when 2 or more feeds are fed together, the digestibility of each feed is affected; is this usually negative or positive?
negative
is digestibility of low fibre foods better in ruminants or non-ruminants?
relatively similar
is digestibility of high fibre foods better in ruminants or non-ruminants?
ruminants
what term is most often used for digestibility?
apparent, estimated, or true
apparent
does an increased feeding level in ruminants usually increase or decrease digestibility?
decrease
How is in vitro digestibility assessed?
through work in labs
this is whole animal studies that provides accurate measure of feed digestibility and baseline information using total collection trials ; it is time consuming, expensive, and has ethical implications
measuring digestibility in vivo
what are 2 limitations of total collection trials
- site of digestion and absorption unknown
- colonic processes undermine establishing appropriate nutritional value
how to avoid the need for total collection in vivo digestibility measuring
indigestible inert markers
what is the equation for DM digestibility when using indigestible inert markers
(g marker/kg feces - g marker/kg food) / g marker/kg feces
this is measuring digestibility in the lab; less time consuming, expensive, and laborious
-uses rumen or cecal fluid, or feces
measuring digestibility in vitro
this measures the energy content of foods by converting foods to heat energy; metal chamber in insulated tank of water, sample of feed ignited & difference in temp of water measured
bomb calorimetry
this value is the measurement of heat produced by the food in bomb calorimetry
gross energy (GE) value
what is the GE content of carbohydrates
17.5 MJ/kg
what is the GE content of fats
39.0 MJ/kg
what is the GE content of protein
24.0 MJ/kg
farm foods predominately consist of this chemical ingredient
carbohydrates
most common farm foods have a GE content of this
18.5 MJ/kg DM
the GE (gross energy) of food minus GE of feces gives this energy of food
DE (digestible energy)
the DE (digestible energy) minus (urine GE + gaseous GE) gives this energy of food
ME (metabolizable energy)
the ME (metabolizable energy) minus heat increment give this energy of food
NE (net energy)
for ruminants what to multiply by DE to estimate ME
ME = 0.8 x DE
for monogastrics, what to multiply by DE to estimate ME
ME = 0.96 x DE
what 2 ways does food produce heat
from digestion and from metabolism
is NE efficiency larger for maintenance or for productive functions
maintenance
most systems use this energy value for food
ME (metabolizable energy)
the k factor for calculating NE from the ME value Km is for this
maintenance
the k factor for calculating NE from the ME value Kl is for this
milk production
the k factor for calculating NE from the ME value Kw is for this
work
the k factor for calculating NE from the ME value Kg is for this
growth
this energy system is usually used for ruminants (DE, ME or NE)
ME (metabolizable energy)
this energy system is usually used for pigs (DE, ME, or NE)
DE (digestible energy)
why is DE energy system traditionally used for pigs?
simpler system than ruminants, less fibre in diet, limited range of feeds
this energy system is usually used for poultry (ME, DE or NE)
ME (metabolizable energy)
why is ME easier to measure in poultry than DE?
urine and feces are voided together (would need to separate urine out from excreta for DE)
this energy system is usually used for dogs and cats (DE, ME, or NE)
ME (metabolizable energy)
this energy system is usually used for horses in the UK (DE, ME or NE)
DE (digestible energy)
which nutrient has the greatest nutrient density? (carb, fat, or protein)
fat
which nutrient provides the most energy in animal nutrition? (carb, fat or protein)
carbohydrate
what is the equation for DE?
Feed GE - Fecal GE
what is the equation for ME?
DE - (urinary GE + Gaseous GE)
what is NE?
ME - heat increment GE
this content is calculated from analyzing the N content of a substance (feed, feces, excreta); expressed g/kg fresh or DM
protein
protein contains on average this percent of N
16%
what to multiply N by to get Crude Protein (CP)
6.25
this is an estimate of the total protein in feed
crude protein
this type of amino acid must be supplied in the diet
essential AA
this type of amino acid can be synthesized in the animal
non-essential AA
this is defined as the total digestible true protein (AA) available to the animal for metabolism after digestion and absorption; system used for ruminants
Metabolizable Protein (MP)
this protein is synthesized from RDP by microbes in the rumen; digested in abomasum and small intestine
Digestible microbial true protein (DMTP)
this protein is the fraction of feed not degraded during passage through the rumen; the fraction that is digested in the abomasum and small intestine
Digestible undegraded protein (DUP)
what is the equation for Metabolizable Protein (MP) in ruminants?
MP = DMTP (digestible microbial true protein) + DUP (digestible undegraded protein)
approximately this percent of UDP (undegradable dietary protein) is digestible
90%
How is crude protein determined?
measuring nitrogen content of feed
why is crude protein 6.25 x N?
because protein contains 16% N
what are the two components of the MP system?
DMTP + DUP
what 4 factors are required to be known in order to calculate a ration formula
- nutrient requirements
- feedstuffs available
- feed intake achieved
- any ingredient limitations
name some feed factors that must be considered (6)
- palatability
- digestibility
- costs
- availability
- variability
- anti-nutritional factors
this method of formulating diets is typically used for production of complete diets
computer-based systems
dogs, cats, pigs, poultry, and small pets require this type of diet
complete diets
ruminants and horses require this type of diet
partial diet
name the four step procedure of practical ration formulation
- determine weight/condition of animal
- establish use of animal
- calculate nutrient requirements
- formulate diet/ration
what level of ammonia in silage and hay is good preservation
less than 10
what level of ammonia in silage and hay is moderate preservation
10-15
what level of ammonia in silage and hay is poor preservation
greater than 15
what level of lactic acid (g/kg DM) in silage is good fermentation
8-12 g/kg DM