Review Questions Ch. 4
Review Answers
• 1. Long, complex organic compounds formed
when amino acids are combined with one another
into polymers. Contain carbon, hydrogen, oxygen,
nitrogen, sulphur, and sometimes phosphorus and
iron.
• 2. Leaves, petioles, and seeds.
• 3. Simple forms of amino acids, not as complex
as proteins.
Review Answers
• 4- All the nitrogenous compounds found in a feed.
• 5- All nitrogenous compounds found in a feed.
Includes protein and nonprotein nitrogen. Found
by the amount of nitrogen content and multiplying
by 6.25. The feed is treated chemically, causing it
to release ammonia. The ammonia is titrated to
determine the percent of nitrogen it contains.
Review Answers
• 6- Approximate amount of protein available for
use by the animal.
• 7- Ruminants utilize both protein and NPN
through microbial action in the rumen.
Nonruminant animals cannot use the amides NPN
as a substitute for the essential amino acids.
• 8- Organic acids containing one or more alphamino groups.
Review Answers
• 9- Essential amino acids are those which must be
provided in the ration of nonruminant animals
cannot synthesize them fast enough. Nonessential
amino acids are needed by animals but are
synthesized in the body from other amino acids.
• 10- High quality: good balance of amino acids.
Poor quality: deficient in amount or balance of
amino acids.
Review Answers
• 13- Important for muscles, cartilage,
ligaments, nerves, brain, blood cells,
internal organs, skin, hair, wool, feathers,
hooves, horns and bones. Needed for
maintenance, finishing, work, and wool
production.
• 14- Young animals, and during gestation
and lactation.
Review Answers
• 15- Depressed performance, higher production
costs. Reserve from blood and liver, in cattle, are
used up quickly. Reduced feed intake, poor
muscular development, loss of weight, reduced
fertility in females.
• 17- Protein is usually high in energy, but is to
expensive to feed exclusively as an energy feed.
• 18- Improperly handling, low moisture, improper
storage.
Review Answers
• 21- Direct cut grass silages, sorghum
silages, and high moisture corn.
• 23- Determined by comparing the excreted
protein in the feces and urine with the
protein intake in the diet. In general, animal
protein feeds have a higher biological value
than plant proteins because they contain a
better balance of amino acids.
Review Answers
• 24- Feeds high in amino acids, generally over 20
percent crude protein.
• 25- Animal origin and plant origin.
• 26- Soybean meal. Most economical, high
protein content.
• 29- 37-38% protein and 17-18 % fat. Soybeans
should be limited to not more than 20%. Soybean
meal can be as high as 44%.
• 31- Because the rumens have microbes that break
the urea down and the nonruminants do not.
Review Answers
• 34- Urea is not toxic, however, ammonia is
released by microbe activity in the rumen and may
be toxic if more ammonia is released than can be
completely utilized by the microbes.
• 37- Legumes contain more protein than grasses.
Both are lower in protein than the oil meals.
Forages harvested in the early stages of growth
have a higher protein level than more mature
forages.
Review Answers
• 38- Grains vary widely in protein level and
are not fed primarily for their protein
content but as an energy source.
Livestock Nutrition Chapter 5
Minerals
Objectives
• Describe minerals used in animal nutrition.
• List sources of minerals for animal feeding.
• Describe the functions of minerals in animal
nutrition.
• Describe the deficiency symptoms caused
by a lack of minerals in the ration.
• Discuss the requirements for minerals in the
ration.
Minerals Defined
• Minerals are inorganic, low or no Carbon.
• Two groups, major or macro and trace or micro.
• Major include sodium, chlorine, calcium,
phosphorus, potassium, magnesium and sulphur.
• Trace include chromium, cobalt, coper, fluorine,
iodine, iron, manganese, molybdenum, selenium,
silicon, and zinc.
Functions of Minerals
• Mineral content of animal bodies range
from 2 to 5%.
• Provide material for growth of bones, teeth
and soft tissues.
• Regulate vital chemical processes, aid in
muscular stimulation and activity,
reproduction, digestion of feed, repair of
body tissue, formation of new tissue.
Functions of Minerals
• Bones contain 25% minerals, Ca, 36%, P
17%, Mg .8%.
• Minerals also affect nerve irritability.
• Ca and P are essential for production of
eggs.
Deficiency symptoms
• Most ration deficiencies come from soil
deficiencies.
• Mineral deficiency may also result because
of poor utilization by the animal.
• Interrelationships between vitamins and
other minerals, water.
Sources of Minerals
• Commercial feeds such as protein supplements or
mineral premixes usually contain both major and
trace minerals.
• Feed tags will show min and max amounts of
major and micro minerals.
• Sodium and chloride are guaranteed as the
compound salt.
• Calcium and phosphorus are usually supplied in
commercial feeds by adding monocalcium
phosphate, dicalcum phosphate.
Minerals in the Ration
• Minerals are usually added to the ration
either by feeding them free choice or
including them in the mixed ration.
• Trace minerals can be deficient because of
the soil in the area where the feed is grown.
• Feeding or roughages or concentrate rations
only can result in trace deficiencies.
Minerals in the Ration
• NaCl, Ca and P are the minerals most likely to be
need in the ration.
• 70% of the mineral content of an animals body is
Ca and P.
• When livestock are on pasture or are not being fed
a concentrate feed, then minerals must be supplied
free choice.
• Animals do not do a good job of balancing their
mineral needs when given a free choice of several
minerals.
Calcium
•
•
•
•
Bones and teeth, 99%.
Milk and eggs.
Most important to lactating animals.
Important for muscle and nerve
development.
• Maintaining the acid-base balance of the
body fluids.
Calcium Deficiency symptoms
• Abnormal and weak bone growth.
• Young can develop rickets.
• Without Ca, the joints of young animals become
enlarged, bones weak, soft and deformed.
Animals are stiff with arching backs.
• Older animals develop “stiffs” or osteoporosis.
• Ca deficiency in older pregnant animals manifest
itself as paralysis of the hindquarters.
Calcium Interrelationships
• Ca:P, 1:1 to 2:1, excess Ca will result in
poor utilization of other minerals.
• An excess of P decreases the absorption of
Ca.
• An excess of Mg decreases the absorption
of Ca.Deficiency of vitamin D prevents the
proper utilization of Ca.
• Toxicity may occur, result in kidney stones.
Ca Sources
• Grains, byproducts, straw, dried mature grasses
and protein supplements from plant sources
contain the least amount of Ca.
• Legume forages and animal-origin protein
supplements are the highest in Ca content.
• Rations high in grain need a higher level of Ca
supplementation, while legume forage rations
need little or no added Ca.
• Ca supplements are derived from two basic
groups, Ca phosphates and CaCo3.
Ca Sources
• CaCo3 materials have about 35-40% Ca.
• Ca phosphate materials contain 30% Ca and
14-20% P.
• Ca phosphates are usually more expensive.
P Major Functions
• 80% of the P in the body is found in the
bones and teeth.
• Affects appetite, milk and egg production,
reproduction and conversion of carotene to
vitamin A and utilization of Vit. D.
P Interrelationships
• Excessive amounts of Ca and Mg in the diet
reduces P absorption.
P Sources
• Wheat bran, wheat middlings, cottonseed meal,
linseed meal, meat scraps, tankage, fish meal and
dried skim milk.
• Legume and grass feeds grown in fertile soils are
good sources of P.
• Adequate Vit D levels improves the assimilation
of P.
• Cattle utilize 60% and swine 50% of the P from
plant sources.
• Fertilizer superphosphate should not be used.
Ca & P Ratio
• The optimum ration varies with specie, type
of feed and the Vit D level.
• The ratio is not as important with adequate
Vit D is present.
• Nonruminant ratios 1:1 to 2:1
• Ruminant ratios 1:1 to 7:1.
NaCl Functions
• Cattle, sheep and horses usually require more
NaCl because of the high levels of forages in their
diets.
• Most grains and forages produced on non-irrigated
soils are low in Na and Cl.
• Important for maintaining osmotic pressure in the
body cells.
• Na the major mineral responsible for maintaining
a neutral pH level in the body tissues.
• Cl is essential for the formation of hydrochloric
acid in digestive juices. Both minerals affect
muscle and nerve activity.
NaCl Deficiency
• If temporarily deprived of NaCl they may
develop an abnormal appetite for dirt,
manure or urine.
• No specific symptoms of NaCl deficiency,
general unthrifty appearance, slow growth
rough hair coat and poor performance.
• Delayed reproduction, infertility and
delayed sexual maturity.
NaCl Ration Requirements
• NaCl may be mixed at a level of .25 to .50
% and or fed free choice.
• During lactation period, include salt at
about one percent of the ration for cattle,
sheep and horses.
NaCl Sources
• Fed as block, loose or in the mineral mix.
• Use salt as a carrier for trace minerals
because of the improved palatability of mix.
• NaCl fed to cattle on pasture often has
organic iodine added to prevent foot rot and
Mg oxide added to prevent grass tetany.
• A 20 to 50% of the overall mineral mix in
either plain or trace-mineralized form.
NaCl Toxicity
• Very seldom happens unless animal is
restricted in their access to water.
• Ruminants have been found to have levels
as high as 15%with no toxicity resulting.
• Nonruminants are subject when dietary
levels are above 8%.
• Symptoms include staggering, blindness,
nervous disorder and hypertension.
K Functions
• Affects osmotic pressure and acid-base
balance, muscle activity and the digestion of
carbohydrates.
• Most rations contain enough K, therefore it
is seldom added to a ration.
K Sources
•
•
•
•
Forages are high in K, 3-4%.
Grains and concentrates .3-.7%.
Animals need less than 1% K.
Cattle and sheep on high concentrate diets
may require supplements.
K Deficiency Symptoms
• Symptoms are not specific.
• Include poor appetite, lower feed efficiency,
slow growth, emaciation, stiffness, diarrhea
and decreased milk production.
K Excess in Diet
• Poor assimilation of Ca and Mg.
• High K intake will result in increased urine
output.
• Toxic levels will result in diarrhea, tremors
and heart failure.
• In soils high in K producing forage low in
Mg and Ca. If this forage is the main diet,
the low Mg causes grass tetany.
Mg Functions
• Activates several enzyme systems, proper
maintenance of nervous system,
carbohydrate digestion and the utilization of
P, Zn, and nitrates.
• Necessary for normal skeletal development.
Mg Deficiency Symptoms
• Low level result in decreased utilization of P,
cause vasodilation.
• Acute Mg deficiency results in grass tetany.
• Levels lower than .001% in the blood.
• The animals become nervous, stagger and fall
down.
• Cattle and sheep grazing on grass pasture, small
grains, on highly fertilized fescue in late winter or
early spring.
Mg Interrelationships
• Adding Mg causes Zn deficiency.
• To much Mg in the ration interferes with
metabolism of P and Ca.
Mg Sources
• If diet is low in Mg, the bones will provide
its reserve.
• A little more than one ounce of Mg per head
per day for cattle is enough.