Transcript Chapter 4 Livestock Nutrition

Review Questions Ch. 3
• 1. Maintain vital life processes.
• 2. Heat production of the animal while it is at rest
and not digesting food.
• 3. Beating of the heart, maintenance of blood
pressure, transmission of nerve impulses,
breathing, work of other internal organs.
• 5. Work of vital organs, nutrient utilization,
normal activity, work, shivering.
Review Questions Ch. 3
• 6. The temperature at which an animal
must increase the oxidation of nutrients to
increase body temperature. Lower
environmental temperature may require
additional energy nutrients.
• 8. No. Some energy is lost through the
feces, urine, and gases produced in the
body.
Review Questions Ch. 3
• 9. Animals will require more energy in rations if
the are pregnant, producing milk or at hard work.
It is only after all the maintenance needs of the
animal are met that energy nutrients can be used
for growth, lactation and pregnancy.
• 10. Carbohydrates, fats and oils.
• 11. Carbohydrates, readily available, easily
digested, generally lowest in cost.
Review Questions Ch. 3
• 12. Organic compounds, occur as compound
substances in feed, a monosaccharide, of which
glucose is the simplest form.
• 14. Simple sugars containing six carbon atoms.
• 18. Seeds, roots and tubers.
• 19. Fiber increases digestibility, yet it is low in
palatibility, helps microbes, adds lubricants to the
digestive system.
Review Questions Ch. 3
• 20. 2.25 times.
• 22. Saturated: two hydrogen atoms
attached to each carbon atom and three
hydrogen atoms attached to the carbon atom
at the end of the chain. Unsaturated:
contains one or more pairs of double-bond
carbon atoms from which the hydrogen
atom has been removed.
Review Questions Ch. 3
• 23. Linoleic, linolenic and arachidonic.
• 24. Raise energy level of diet, improve
flavor, texture, and palatability of feed.
• 25. Corn, barley, beet pulp.
• 27. Dried beet pulp; usually used in dairy
cattle, adds bulk, makes rations more
palatable, mild laxative.
Review Questions Ch. 3
• 28. Animal fat.
• 29. Can cause scouring, improves
palatability, aids rumen microbial activity,
reduces dust and adds sweet flavor.
• 30. Numbers 1-30 pg. 36 and 37.
Chapter 4 Livestock Nutrition
Protein
Objectives
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Describe protein
List sources of protein.
Describe the functions of protein.
Describe the symptoms of protein
deficiency in the animal.
• Discuss non-protein nitrogen sources.
Proteins
• Long complex organic compounds that are
formed when amino acids are combined
with each other into polymers.
• Contain carbon, hydrogen, oxygen,
nitrogen, sulphur and sometimes
phosphorus and iron.
• All proteins in the food chain originate from
plants.
Proteins
• Digestion of plant protein by the animal
provides the amino acids used in the body
to form animal protein.
• Plant cell nucleus and protoplasm is mainly
protein
• Most protein in plants is found in leaves,
petioles and seeds.
Crude protein
• All of the nitrogenous compounds found in a feed.
• The nitrogen content of protein averages 16%.
• A commercial feed tag shos the guaranteed
minimum crude protein content of the feed as a
percent of the weight.
• Not all crude protein in a feed is digestible.
• 60% of a roughage ration is digestible.
• 75-85% of a high concentrate ration is digestible.
Digestible protein
• A rations approximate amount of protein
available for use by the animal.
• The difference between the protein content
of the feed and what is found in the feces.
Crude Protein
• Because ruminants can utilize both protein
and NPN through microbial action in the
rumen, the use of crude protein value is
valid and realistic when balancing ruminant
rations.
• Non-ruminant animals cannot use the
amides (NPN) as a substitute for the
essential amino acids.
Amino Acids
• Organic acids containing one or more alpha-amino
groups that form the building blocks of proteins.
• The average protein contains 100 or more amino
acids.
• There are 20 to 22 amino acids commonly found
in proteins.
• Amino acids are classified by the number of acidic
and basic carboxyl groups.
Essential Amino Acids
• Those acids which must be provided in the ration
of non-ruminant animals because the animals
cannot synthesize them fast enough to meet their
needs.
• Ruminant animals can generally synthesize the
essential amino acids by rumen microbial action.
• Non-essential amino acids are synthesized in the
body from other amino acids and therefore, do not
have to be provided in the ration.
• There are 10 essential and 13 nonessential for
swine and 14 for poultry.
Amino Acids
• The quality of a protein is related to its amino acid
content.
• High quality protein have a good balance of the
essential amino acids.
• Poor quality proteins are deficient in amount or
balance of the essential amino acids.
• When feeding non-ruminant animals, the amino
acid content of the protein is of greater importance
than the percent of protein present in the feed.
Limiting amino acid
• The term for the essential amino acid that is
present in the lowest amount in the feed.
• Essential amino acids are required in the ration in
definite proportions.
• Amino acids may supplement each other when
two different protein feeds have different amounts
of a limiting amino acid.
• Because of this supplementary effect, it is
recommended that more than one source of
protein be supplied in the diets of non-ruminants.
Functions of Proteins
• An essential part of all living tissue.
• Needed for maintenance, finishing, work, and
wool production, the greatest need is for growth,
reproduction and lactation.
• No other nutrient can replace protein in the diet.
• Depending upon the species, the minimum level of
protein needed in the ration ranges from 8 to 21
percent.
• More protein is required for younger animals.
• Protein requirements are also higher during the
gestation and lactation periods than at other times.
Protein Deficiency
• A shortage of protein n the diet results in a
variety of symptoms.
• Including depressed performance, higher
production costs.
• Unthriftyness poor hair coat.
Dairy Cattle
• Limited amounts of protein is stored n the blood,
liver and muscles of cattle.
• When a diet is deficient in protein, this reserve is
quickly used up and signs of deficiency appear.
• During lactation the solids-not-fat content of the
milk is reduced.
• Will lower immunity and reduce hormone
secretions.
Beef Cattle
• Appetite depression, which results in
reduced energy intake.
• Irregular or delayed estrus in breeding
females.
• Loss of weight, slow growth and reduced
milk production.
Sheep
• Also depresses appetite, reduces feed intake
and resulting in an energy shortage.
• Poor growth rate, poor muscular
development, and loss of weight.
• Wool production is lower and reproductive
problems also appear.
• When the deficiency is drastic anemia will
result.
Horses
• Depressed appetite is the primary indication
of protein deficiency in horses.
• Mature horses will lose weight and young
horse will grow slowly.
• Reduction in fertility in mares.
Swine
• Slows down growth.
• Increases susceptibility to bacterial
infection.
• Anemia, and increased fat concentration in
the liver.
Protein as an Energy Source
• When excess protein is included in the diet the
excess may be used as an energy source.
• The remaining material is used for energy need or
stored as body fat.
• Protein feeds are more expensive than energy
feeds therefore they are not as economical.
• Every effort should be made to have the correct
balance of amino acids in the diet.
Unavailable Feed Protein
• Feed can lose protein due to improper
storage.
• When calculating rations, adjustments must
be made for this loss of protein.
Protein Solubility
• Poorly soluble crude protein when all silage
rations are fed.
• Quickly attacked in the rumen by bacteria
enzymes and degraded to simpler compounds.
• Byproduct concentrate feeds often contain a high
level of soluble crude protein which makes them a
poor choice in the ration when feeding silages.
Biological Value of Protein
• In feed, the percent of digestible protein that is
retained by the animal for use is a measure of the
biological value of the protein.
• A protein feed with a good balance of the essential
amino acids will show less excreted protein,thus
having a high biological value.
• Animal protein feeds have a higher biological
value than plant proteins because they contain a
better balance of amino acids.
Plant Protein Supplements
• Feeds that are high in amino acids.
• A protein supplement generally contains over 20%
crude protein.
• Two groups of supplements, plant and animal
origin.
• Protein supplements of the animal origin are
considered to be of higher quality because they
contain a better balance of the essential amino
acids.
• Not all of the animal origin protein is superior.
Plant Protein Supplement
• The major source of plant protein supplements is
oil seed byproducts.
• Soybean meal is the most used and economical,
containing between 43-48% protein on a dry
matter basis.
• Cottonseed and linseed meal are also important
plant protein sources.
• Dehydrated alfalfa meal is also an important
source of plant protein.
Fat Extraction Methods
• The three kinds of extraction methods are used;
hydraulic, expeller and solvent.
• Hydraulic is a mechanical method, leaving a lot of
the oil in the meal, rarely used today.
• The expeller method was developed for soybeans,
mechanical, uses a screw press, still widely used
in the cotton belt.
• Solvent, is a chemical process, used since 1940’s.
Removes almost all of the fat, all soybean meal is
being produced using the solvent method.
Soybeans as a Protein Source
• Soybeans average 37-38% protein and 1718% fat.
• Should be no more than 20% of the total
grain mix.
• Soybeans contain urease and antitrypsin.
The release ammonia from urea, and
prevent the effectiveness of the enzyme
trypsin.
Urea
• A non-protein nitrogen compound that contains
45% nitrogen.
• Manufactured by combining atmospheric nitrogen
with ammonia and carbon dioxide.
• Most common of the non-protein nitrogen sources
used in ruminant rations.
• In beef cattle it can be used to provide all the
supplemental protein needed for animals over 600
pounds.
Urea
• Not palatable and must be thoroughly
mixed in the ration to be acceptable to the
animal.
• Mixing urea with molasses increase its
palatability.
Urea Toxicity
Urea is a normal byproduct of protein metabolismin
animals and is not toxic.
However, the ammonia produced by mocrobe
activity in the rumen may be toxic if more is
released than can be completely utilized by the
microbes.
Two mechanisms operate to keep ammonia below a
toxic level, one the conversion of ammonia to
microbial protein, and two, the liver where
ammonia is combined with carbon dioxide to form
less toxic urea.
Nitrates/Nitrites
• Plants with a high accumulation of nitrates
may have a toxic effect on livestock.
• Causes of high nitrate accumulation include
excess levels of nitrate in the soil, dry
conditions followed by inadequate soil
moisture an imbalance in soil fertility.
• Annual grasses are more likely to
accumulate excess nitrates.
Nitrates/Nitrites
• Cereal grains generally do not cause a nitrate
problem.
• Symptoms include, poor appetite, slower gains,
low production, watery eyes, rough hair coat and
lower conception rate.
• Pinkeye and foot rot are secondary infections from
nitrate poisoning.
• Supplementing Vitamin A can reduce the effects f
nitrate poisoning.
• Monogastric animals are more tolerant of higher
nitrate levels in the feed than are ruminants
because there is less reduction of nitrate to nitrite
by non-ruminants.
Other Non-protein Nitrogen
• Include ammoniated molasses, ammoniated
beet pulp, ammoniated cottonseed meal,
ammoniated citrus pulp, ammoniated rice
hulls, ammonia in anhydrous (without
water) or water form can be added to corn
silage.The digestibility of straw and other
low quality roughages is improved by the
addition of ammonia.
Byproduct Feeds as Protein
• Brewers grain, Wheat bran, malt sprouts,
beetpulp and cereal grain screenings.
• Beet pulp will improve palatibility.
• Wheat bran provides bulk and fiber.
• Whey is economical in dried or liquid form
but is relatively low in protein.
Grass and Legume Forages
• Legume forages contain more protein than grass
forages.
• Both are lower in protein than the oil meals.
• The crude protein content of forages is the best
overall indicator of their feeding value in livestock
rations.
• Forages harvested in the early stages of growth
have a higher protein level than more mature
forages.
Grain as a Protein Source
• Vary greatly in protein level, fed mainly as
an energy source.
• Protein content of grains must be taken into
account when formulating rations.
• Corn, the most fed grain in livestock rations
is deficient in lysine.
• Deficiencies of amino acids in the grains are
important in formulating rations.