Animal Nutrition
Need for Nourishment
• body processes require the use of
energy
• obtained from ingested food or
stored fat
• animal must have food to store
energy in fat cells
Need for Nourishment
• animals spend most of their
time in search of food
• maintenance ration must be
met first
Need for Nourishment
• wild animals eat a variety of foods
to obtain proper nutrients
• agricultural animals depend on the
producer to provide balanced a
ration
Feedstuff
• one component of a feed
ration
• not normally fed by itself
Nutrients
• Water
• Protein
• Carbohydrates
• Fat
Nutrients
• fiber
• vitamins
• minerals
Metabolism
• all the chemical and physical
processes that take place in
the body
Metabolism
• anabolism - metabolism that
builds tissue
• catabolism - metabolism that
breaks down materials
Water
• most abundant compound in
the world
• animals must have frequent
intakes of water to remain
alive
Water
• provides basis for all of the
fluid of the animals body
• bloodstream requires liquid
for circulation
Water
• digestion requires moisture
for breakdown of nutrients
and movement of feed
• needed to produce milk
Water
• provides cells with pressure
to allow them to hold their
shape
• helps body to maintain
constant temperature
Water
• flushes the animal’s body of
waste and toxic materials
• a loss of 20% of body water
will result in death
Water
• animals generally need about
three pounds of water for
every pound of solid feed
they consume
Protein
• largest and most costly part
of the ration
• composed of amino acids
Protein
• building blocks of life
• tissue development
• muscle production
Protein
• enzymes are composed of
protein
• protein can be used to supply
energy
Protein
• some animals need more
protein than others
• young animals
• lactating (milk producing)
animals
Protein
• twenty three amino acids
–ten essential
• Lysine, methionine, tryptophan etc.
• Esp. required in the diet for nonruminants
–thirteen nonessential
Protein
• balancing rations is based on
the amino acid content more
for non-ruminants
Protein
• crude protein content
• total amount of protein in a feed
• Feed analysis - calculated by
multiplying nitrogen content
percentage times 6.25
• Digestible protein
Protein
• Digestible protein
• the protein in a feed that can be
digested and used by the animal
• usually about 50-80% of crude
protein
Protein
• protein sources
• animal
–slaughterhouse by products
–dried fish meal
Protein
• plant
–superior to animal sources
–cottonseed meal
–soybean meal, linseed meal
–peanut meal, corn gluten meal
Feeding Livestock for Energy
• Calorie, (cal)- the amount of heat
energy required to raise the
temperature of one gram of water one
degree C
• Kilocalorie, 1,000 calories.
ENERGY
• Gross Energy (GE)- the total amount
of heat released when a substance is
completely oxidized in a bomb
calorimeter.
• Digestible Energy (DE)- The gross
energy of feed consumed minus the
gross energy excreted in the feces.
Energy cont.
• Metabolizable Energy (ME)- The gross
energy of the feed minus the energy in the
feces, urine, and gaseous product of
digestion.
• Net Energy, (NE)- the metabolizable energy
minus the heat increment. Used for growth,
maintenance, production, work, fetal
development and heat production.
Energy cont.
• Carbohydrates found in plants include
starch, sugars, hemicellulose, cellulose,
pectin's, gums, & lignin.Sugars are the most
easily digested while cellulose and lignin
are more difficult.
• 75% of all the dry matter in plants is
carbohydrates.
Functions of Energy
• Energy nutrients are needed for the maintenance
of life in the animal.
• Maintains basal metabolism.
• Basal metabolism is defined as the heat production
of the animal while it is at rest and not digesting
food.
• Beating of the heart, maintenance of blood
pressure, transmission of nerve impulses,
breathing and work of other internal organs.
Functions of Energy
• When animals are on full feed they seldom reach
lower critical temperature unless the weather is
extremely cold.
• It is only after all the maintenance needs of the
animals are met that energy nutrients can be used
for growth or production.
• Fattening livestock requires a large amount of
energy nutrients.
• Energy not used for other needs is deposited as
fats within the body tissues.
• The deposition of fats makes the meat tender,juicy
and gives it a better flavor.
Carbohydrates
• main source of energy
• compounds of carbon,
hydrogen and oxygen
• include sugars, starches and
cellulose
Carbohydrates
• types of sugars
• monosaccharides - simple
sugars
• glucose
• fructose, galactose
Carbohydrates
• disaccharides - complex
sugars
• sucrose
• lactose
Carbohydrates
• Organic compounds made of carbon,( C ),
Hydrogen (H), & Oxygen (O).
• Each C2H2O molecule is made up of 40% C, 7%
H and 53% O2.
• Carbohydrates found in plants include starch,
sugars, hemicellulose, cellulose, pectin's, gums, &
lignin.Sugars are the most easily digested while
cellulose and lignin are more difficult.
• Carbohydrates in the feed are changed to simpler
forms.
Carbohydrates
• 75% of all the dry matter in plants is
carbohydrates.
• More easily digested forms of carbohydrates are
generally found stored in the seeds, roots and
tubers of the plant.
• Hemicellulose and cellulose are converted to
glucose.
• Because hemicellulose and cellulose require more
energy, they are less efficient sources of energy
for the animal.
Carbohydrates
• Starch is made up of many molecules of glucose.
• Grains have a high feeding value because the
starch is easily digested.
• Ruminant animals because of bacterial action in
the Rumen can utilize large portions of coarse
roughage.
• Non-ruminants have less ability to utilize energy
from fiber.
• The young of all species require more easily
digested feeds.
Sources of Energy
Concentrates
• A major source of energy nutrients is the
grains and grain byproduct.
• These feeds are called energy concentrates
or basal feeds when their crude protein is
less than 18% in the air-dry state.
Carbohydrates
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almost all come from plants
generally found in grain
Corn
Oats
Milo/Sorghum grain
Wheat and barley
Shelled Corn
• One of the highest energy feeds available.
• The most widely grown and used feed grain crop.
• Corn produces more #’s of TDN/acre than any
other.
• It is an economical and superior source of energy.
• Consideration must be given to amount to feed,
frequency and combinations with other feeds, in
order to get the most efficient use of this high
energy feed source without causing digestive
problems.
Grain Sorghum
• There are many varieties, milo, kafir and
various hybrids.
• Smaller than shelled corn and may replace
up to 100% of the corn in a feedlot ration.
• Generally rolled or ground when included
in a ration.
Wheat
• High in both energy and protein it is generally not
used in livestock rations because of the high value
as a small grain crop on the cash market.
• Wheat is similar to corn in composition and
feeding value.
• If and when it is used in a ration it is included at
low levels in a mix with other grains because it is
rapidly digested and may cause digestive
disturbances.
Oats
• About 85% of the energy of shelled corn.
• Higher in crude protein than shelled corn and add
fiber and bulk to the ration.
• Help the rumen maintain bacterial and protozoa
function.
• Not a good fattening feed but are used extensively
in rations for horses, young growing stock, show
stock and breeding animals.
• Usually fed rolled, crimped or ground.
Barley
• Almost equal to corn in energy value, but lies
between corn and oats in fiber content.
• Used in a ration in a manner similar to oats.
• Barley may replace up to 50 % of the corn in
rations for fattening animals.
• The grain content of the ration may be decreased
by 10 % if barley replaces all of the corn.
• To improve palatability it is usually steam rolled,
crimped or coarsely ground.
Sources of Energy/Forages
• Forages (roughages) can supply some of the
energy needs in the livestock ration, although they
are not as concentrated a source of energy as the
grains.
• Value of forages for livestock feed is highly
dependent on time of harvesting.
Sources as forages
• As forage plants mature, the crude fiber
content (cellulose and lignin) increases,
which lowers the digestibility of the feed.
• When forages are harvested as silage, more
of the nutritional value of the plant is
preserved.
Pastures
• Properly managed pastures can be a good
source of nutrients.
• Rotating and fertilizing pastures to get the
best yield and nutritional value.
• Quality of pasture must be closely watched
and supplemented with good quality stored
forages when necessary.
Sources of Energy Byproducts
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These include the following:
Dried citrus pulp.
Dried beet pulp.
Potato meal.
Dried sweet potatoes.
Cotton seed hulls.
Beet tops.
Sources of Energy---Molasses
• Common types of molasses are cane or blackstrap,
beet, citrus and wood.
• Molasses is used in rations for cattle, sheep and
horses but is seldom used in swine rations,
because it causes scouring.
• Improves palatability, aids rumen microbial
activity, reduces dust and serves as a binder when
feeds are pelleted.
• Molasses is usually limited to not more than 1015% of the ration.
Dried Beet Pulp
• Primarily used in dairy cattle rations but is
occasionally used in rations for horse, beef
and sheep.
• Adds bulk to rations.
• Makes rations more palatable, mild laxative.
• Should not replace more than 20% of the
grain in a ration.
Fats
• group of organic compounds
known as lipids
• found in plants and animals
• provide and store energy
Fats
• essential fatty acids:
necessary for production of
some hormones and hormone
like substances
Fats
• most important sources are
the grains that contain oil
Lipids (fats & oils)
• Lipids are 77% C, 12% H & 11% O.
• Because there is more carbon and hydrogen
and less oxygen in the molecule, lipids
supply approximately 2.25 times as much
energy as an equal weight of carbohydrates.
• Lipids are classified as simple, compound
and derived.
• Simple lipids are true fat and waxes.
Lipids
• Compound lipids are esters, which contain
groups in addition to an alcohol and fatty
acid.
• Derived lipids are from simple or
compound lipids, separated by hydrolysis.
• Fatty acids are either saturated or
unsaturated.
Lipids
• Fats are used to raise the energy level of the
diet and/or improve the flavor, texture and
palatability of the feed.
• Rations for adult ruminant animals should
contain no more than 3-5% fat and 15-20%
fat for nonruminants.
Sources of Energy---Fats
• A byproduct of packing plants, and poultry
processing plants.
• Commercial feed mixes will contain 1-7% animal
fat.
• Animal fat in the feed reduces the dustiness of the
feed.
• Often treated with antioxidants to prevent the feed
from becoming rancid in storage.
• Beef and dairy rations can contain up to 5% while
swine rations may have up to 20%.
Effects of Energy Deficiency
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Slow growth of young.
A delay in the onset of puberty.
A decrease in milk yield in lactating females.
A shortened lactation period.
A Loss in body weight.
Several kinds of reproductive problems including
reduced fertility and delayed estrus.
Effects of Energy Deficiency
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In sheep, a reduction in wool quantity and quality.
A higher mortality rate.
A lowered resistance to disease.
Weakness, generally poor condition, and unthrifty
appearance.
• Hypoglycemia.
• A loss of subcutaneous fat.
• A reduction in levels of blood glucose, calcium,
and sodium.
Minerals
• inorganic
• have role in providing structural
support for the animal
• bones (calcium and phosphorous)
Minerals
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egg shells (calcium)
DiCalcium Phosphate
other essential needs provided by minerals
aid in construction of muscles, blood cells,
internal organs and enzymes
Minerals
• mineral elements required
• macro – 7
– Ca, P, K, Mg etc.
• micro – 9
– Fe, Se, Mn, Cu, etc.
Minerals
• usually added to feed in their
chemical form
• often fed free choice
• mineral ox or trough
• salt block or loose
Vitamins
• considered micronutrients
• essential for the development
of normal body processes
Vitamins
• health
• growth
• production
• reproduction
Vitamins
• provides animal with ability
to fight stress, disease, and to
maintain good health
Vitamin A
• fat soluble
• converted from beta carotene
Vitamin D
• fat soluble
• depends on ultraviolet light
for synthesis
• can be made commercially
from irradiated yeast
Vitamin E
• fat soluble
• found in several forms of the
organic compound
tocopherol
Vitamin K
• fat soluble
• utilized to form the enzyme
prothrombin
• synthesized in rumen and
monogastric intestinal tract
B Vitamins
• Water soluble
• thiamine: coenzyme in energy
metabolism
• riboflavin: part of two coenzymes
that function in energy and protein
metabolism
Vitamins
• pantothenic acid: component
of coenzyme A
• niacin: involved in
metabolism of far, carbs and
proteins
Vitamins
• pyridoxine: coenzyme
component
• biotin: part of enzyme
involved in fatty acid
synthesis
Vitamins
• folic acid: needed in body cell
metabolism
• choline: component of fats and
nerve tissues
• needed at greater levels than other
vitamins
Vitamins
• B12: coenzyme in several
metabolic reactions
• essential part of red blood
cell maturation
Vitamins
• C: essential in the formation
of collagen
Digestion
• nutrients are converted to a
form that the cells can use
• nutrients are transported by
digestive system
• Reduction of particle size
Digestion
• gastrointestinal tract
• organs that make up the
digestive system
• also referred to as the
alimentary canal
Digestion
• Digestion is breaking feed down into simple
substances that can be absorbed by the
body.
• Digestion occurs when feeds are broken up
mechanically and acted upon by enzymes
and other digestive juices.
• Most absorption of nutrients after digestion
takes place in the small intestine, although
some absorption occurs in the rumen.
Absorption of Nutrients
• Villi are small cone-shaped projection on the wall of
the small intestine. Each villi contains a network of
blood capillaries through which nutrients enter the
blood stream.
• Protein is converted to amino acids.
• Starches and sugars are converted to glucose,
fructose and galactose.
• Crude fiber is converted to short chained fatty acids
or glucose by digestion.
• These nutrients pass into the blood capillaries by
osmosis through the semi permeable membranes.
Absorption of Nutrients
• The two methods of absorption are diffusion and
active transport.
• Diffusion is the movement of molecules from an
area of high concentration to one of low
concentration.
• Active transport is the movement of molecules
from one area to another requiring the expenditure
of energy.
• Amino acids and glucose move by active
transport.
Nutrient Transport
• Nutrients in the water soluble form, are primarily
carried by the blood in the animals body from
where they are absorbed to where they are
utilized.
• Nutrients are used for maintenance, oxidation
provides hear for body temperature and
movement.
• Nutrients are also used for growth and fattening,
fetal development and work.
Monogastric system
• has only one compartment to
the stomach
• process goes through the:
• mouth
• esophagus
Monogastric system
• stomach
• small intestine: duodenum,
jejunum, ileum
–Major site of nutrient
absorption
Monogastric system
• large intestine: cecum, colon,
rectum
Monogastric system
• humans
• dogs
• cats
• horses
Ruminant system
• multicompartment stomach
• ruminant animals are often
called “cud chewers”
• no upper front teeth in
ruminant mouth
Ruminant system
• no enzymes in the saliva
• examples of ruminant
animals:
• cows, sheep, goats
Rumen Compartments
• Reticulum
• has appearance of a
honeycomb
Reticulum
• traps dangerous objects and
prevents them from proceeding
through the rest of the tract.
• Called hardware disease: cow eats
wire, nails, staples
Reticulum
• stores, sorts, and moves feed
back to the esophagus for
regurgitation (throwing up)
Rumen
• functions as a storage vat
• food is soaked, mixed, and
fermented
Rumen
• some absorption of nutrients
• some breakdown of feed
through microbial action
Omasum
• grinds roughage
Abomasum
• only true stomach
• functions similarly to a
monogastric stomach
Feed Quality
• Quality of feed affects its value for animal
nutrition.
• Quality factors include palatability and
nutrient content.
• Improper harvesting or handling will reduce
quality.
• Palatability refers to how well the animal
will accept feed.
Feed Composition Basis
• All feeds contain moisture, depending upon
the form fed, time harvested and storage
time.
• As fed means the data is calculated on the
basis of the average amount of moisture
found in the feed as it is used on the ranch.
• 100% dry matter basis means that the data
presented is calculated on the basis of all
the moisture removed from the feed.