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close this book Agricultural development workers training manual: Volume IV Livestock
close this folder Chapter III: Guidelines and references
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View the document Overview of livestock training
View the document Introduction to animal nutrition
View the document Introduction to feeds
View the document Livestock feed rations
View the document Introduction to disease
View the document Livestock production planning
View the document Livestock production levels
View the document Sample livestock production scenario
View the document Small animal production assessment tool
View the document Farm visits

Introduction to animal nutrition


The basic concepts defined and discussed in this section of the livestock guidelines are also applicable to human nutrition. In the spirit of training integration it is a hope that these guidelines help the trainees develop a deeper understanding of their own nutritional needs by learning about those of animals. Furthermore, many of these concepts can be applied to those people they will be working with in-country. Many of the ideas and concepts covered in this section relate to the topics of health and nutrition in core classes and nutrition in the crops/vegetable training.

Nutrition is the process of changing food to living tissues and maintaining it. Nutrients are substances that:

1. Build and repair body tissue

2. Provide energy

3. Regulate body processes.

The amount of these needed in the body depends on:

1. The species of the animal i.e. simple stomach vs. ruminants

2. Purpose of the animal:

a. Egg, meat, milk, or wool production

b. Lactation/reproduction

c. Growth

d. Maintenance

Many microorganisms have simple nutrient requirements. They are:

a. Inorganic elements

b. Water

c. Source of nitrogen

d. Source of energy

All these can provide growth and production. Higher animals, including man, require more complex nutrient needs. Simple stomach or monogastric animals (man, chickens, and pigs) unlike ruminant animals (cows, sheep, and goats) require more complete proteins and vitamins in their diet because they cannot produce protein that includes all of the essential amino acids with Just a supply of nitrogen.

Nutrients can be divided into six categories. These are water, carbohydrates, fats, proteins, vitamins, and minerals.

I. Water

Water is the cheapest and most abundant nutrient. Consider the following:

1. 65 to 70% of the body weight at birth is water.

2. 40 to 50% of body weight of an animal at marketing is water.

3. 90 to 95% of the blood is water.

Sources of water to the animal include:

1. Drinking;

2. Food;

3. Metabolism (break down of nutrients).

If water is not available or withheld from an animal, the animal compensates in order to produce enough water to maintain its body's normal functioning. First, urine excretion and water in the feces are reduced. Second, the animal metabolizes the tissues present to provide metabolic water, causing weight loss. Third the animal attempts to keep cool seeking shade so as to reduce water loss from evaporation and sweating. Fourth, there is a reduction in feed consumption unless the feed is high in moisture. In low production or survival environments, the animals have probably developed these compensatory mechanisms as a means of survival. Since their owners do not usually provide water, the animals probably have developed a resistance to drought stresses and through time have become hardier animals.

Factors which affect the water requirement:

1. The type of diet, i.e., green forage vat dry forage

2. The purpose of the animal, i.e., lactation vat meat

3. The type of digestive tract, i.e., ruminant vat nonruminant

4. The type of urinary system, i.e., mammals vat birds

Function of water in the animal:

1. Transport of nutrients

2. Chemical reactions

3. Temperature regulation

4. Maintains shape of the body cells

5. Lubricates and cushions the body

Approximate water consumption (mature animal)

1. Swine 1 1/2 to 3 gallons/head/day

2. Sheep 1 to 3 gallons/head/day

3. Poultry 2 parts water for each part of dry feed

II. Carbohydrates (CHO) Energy nutrient

1. These are made up of carbon, hydrogen, and oxygen with chemical similarity of H2O.

2. These include sugars, starches, and cellulose.

3. Very little occurs as such in the animal's body.

4. CHO makes up 3/4 of plant dry weight.

5. It forms the largest part of an animal's food supply.

6. These are formed by photosynthesis in plants.

Classification (by number of sugar molecules)

1. Monosaccharides (simple sugars)

a. Glucose

b. Fructose

c. Galactose

2. Disaccharides

a. Sucrose

b. Malatose

c. Lactose

3. Polyeaccharides

a. Starch. Stored in small amounts in the body in the form of glycogen in the liver.

b. Cellulose. All walls of plant. cells are composed of cellulose.


Crude fiber (cellulose, hemicellulose, & lignin) poorly digested CHO. Nitrogen Free Extract (soluble sugars and starches) readily digested. Function:

1. Energy;

2. Heat;

3. Building stones for other nutrients;

4. Stored in animal's body by converting into fats.

III. Fats - Lipids (either extract)

1. Made up of CHO

2. Produces approximately 2.25 times more energy than CHO or proteins, and more per unit of weight.

3. Composition: Fat = Glycerol and 3 fatty acids.

4. Fatty acids are either saturated or unsaturated.

5. Fatty acids considered essential for animals:

a. Oleic

b. Linoleic

c. Linolenic

d. Arachidonic

6. Fats are located in the animal body just below the skin surrounding the internal organs, in the milk, and marbling. In plants, fats are found in the seed germ or embryo.

7. Function:

a. Energy

b. Heat and insulation

c. Protection

d. Aid in absorption of fat soluble vitamins

e. Marbling

Measuring the energy value:

Although all nutrients are equally important, feedstuffs are usually evaluated on the energy value because:

1. Energy is required in larger amounts than other nutrients.

2. It is the most limiting factor in livestock production and the major cost.

3. When all the other nutrients are present in adequate amount e, the amount of feed consumed is determined primarily by the energy level of the ration.

Energy is usually measured in kilocalories (Kcal). A Kcal is the amount of energy as heat required to raise the temperature of 1 kilogram of water one degree Centigrade. Another system of measuring energy is the Total Digestible Nutrient system (TDN). This system is usually used in determining the energy requirements of ruminants and rabbits. TDN is the sum of the digestible protein, fiber, nitrogen free extract (CHO), and fat X 2.25. It is expressed either as a percentage of a ration or in pounds or kilograms.

The following scheme explains the utilization of energy by the animal:

Gross Energy


Digestible energy

(Similar to TDN)


Fecal Energy

Urinary/Combustible energy Gas


Metabolizable Energy


Heat Increment


Net Energy





Gross Energy is the total potential energy of the foodstuff.

Fecal Energy is energy lost in the form of undigested food residue and energy-yielding metabolic products.

Digestible Energy is GE - FE, Energy received by digestion - similar to TDN.

Gaseous products of digestion = energy lost by combustible gases which escape the body.

Urinary Energy is energy lost in the urine during intermediary metabolism.

Metabolizable Energy is the usual portion of the ingested energy. DE = ME The ME value of feeds is usually used when determining the energy requirements for pigs and chickens. Usually it is a more accurate measure of energy available for the animal.

Heat Increment or HI is the increase in heat after the animal consumes feed.

Net Energy NE = ME - HI. The amount of energy used for maintenance and/or production.

IV. Protein

1. Composed of carbon, hydrogen, oxygen, nitrogen, and sometimes phosphorus and sulfur.

2. Protein contains approximately 16% nitrogen so: % N/16% = Crude Protein = %N x 6.25 16%

3. Protein consists of many molecules of amino acids ( M ) Joined by peptide linkages, i.e., AA1 - AA2 - AA3 - -AAx

Types of Protein

1. True protein: that which is composed of only amino acids.

2. Nonprotein Nitrogen (NPN): compounds which are not true protein in nature but contain N and can be converted to protein by bacterial action.

3. Crude protein: that protein which is composed of true protein and any other nitrogeneous product. % N x 6.25 - Crude Protein

4. Digestible protein: that portion of the crude protein which the animal can digest.

5. Essential amino acids: those amino acids which are essential to the animal and are needed in the diet because the animal's body cannot synthesize them fast enough to meet its requirement. Some of the most limiting amino acids (most difficult to supply in the diet) are: Lysine, Methionine, and Tryptophane.

Non-essential amino acids: those amino acids which are not needed in the diet but are still essential for the animal

Measure of Protein

Protein quality refers to the amount and ratio of the essential amino acids.

Measures Used:

1. Biological value (BV): A measure of the relationship of protein retention to protein absorption; or the % of true absorbed protein that is utilized for maintenance and/or production. A protein with a BV of 70 or more (70% of the intake of N is retained) is considered capable of supporting growth if the caloric value of the diet is adequate. If less than 70%, the protein is less capable of supporting life.

Examples of measurement:

Biological value

a. Whole egg protein


b. Meat protein

72 - 79%

c. Cereal protein

50 - 65%


2. Net protein utilization (NPU) is a measure of protein quality expressing both the digestibility of the protein and the BV of the amino acid mixture absorbed from the intestine. NPU = BV x digestibility.

Barrel Concept explaining limiting amino acids: See illustration I-1.

In order to understand the concept of limiting amino acids, the barrel concept is most helpful. Consider the barrel as the structure which holds amino acids together, like peptide bands, and each stave of the barrel is an amino acid (essential or non-essential). Consider the barrel's purpose, holding water, as a special protein which, let us say, makes muscle. The amino acid and the amount of water the barrel will hold (to continue the analogy, muscle that will be made) la limited to the amount of lysine available. In the drawing, methionine is the next moat limiting AA. The lengths of the other staves (amino acids) above the length of the lysine stave will not be used for holding water or making muscle. The nitrogen portion of these amino acids will be passed in the urine and the C, H. & O will be utilized as energy. This is a very inefficient method of stippling energy needs because:

1. Protein, per unit of weight, is usually more expensive than carbohydrates.

2. The breaking down of protein to provide energy is stressful to the animal's system.

If a protein is not supplying all the essential amino acids in the right proportions at the critical time for growth and development, then the protein is not considered complete. Eggs and meats are usually considered complete proteins. No single plant protein is complete, but soybeans and peanuts come close.

Complementary proteins: When a complete protein is not available, different feed ingredients can be combined which can provide a more complete protein. Examples of supplementary action between different proteins would be beef blood meal, which is low in isoleucine and high in lysine and tryptophan, and corn gluten meal, which is high in isoleucine and low in lysine and tryptophan. When combined in a ration 1 part BBM to 4 parts of CGM, the mixture provides all three amino acids in considerable amounts to promote growth.

Barrel concept chart

LYSINE is the most limiting.

METHIONINE is the second most limiting.

Lysine determines how much water the barrel will hold, or muscle that will be made.

The second example would involve soybean and sesame meal. Soybeans are high in lysine but low in methionine. Sesame is low in lysine but high in methionine, These two, when combined, provide a more complete protein.

Examples of complementary foods can be seen in food mixtures throughout the world: Rice and beans, rice and lentils, and tahini (chickpeas and sesame paste).

Purpose/Function of Protein

1. Essential for growing cells

a. Maintenance

b. Production, i.e., eggs, meat, milk, and wool

c. Reproduction

2. Included in the structure of:

a. Enzymes

b. Hormones

c. Catalyst

d. Antibodies

3. May be used for energy.

V. Minerals (See Tables 1-1)

1. Inorganic elements

2. The total mineral content of plants or animals is called ash.


1. Major minerals: Calcium, phosphorus, Sodium, and Chlorine.

2. Trace minerals: Iodine, Potassium, magnesium, manganese, sulfur, iron, zinc, copper, cobalt, and molybdenum.

3. Flourine and Selenium are considered beneficial in small amounts but toxic if in excess.

General Function

1. Skeletal formation and maintenance.

2. Constituent of nucleoproteins which are vital to all cellular activity.

3. Oxygen transport.

4. Chemical reaction in the body.

5. Fluid balance (osmotic pressure and excretions).

6. Regulates acid-base balance.

7. Help in enzyme system.

8. Mineral - vitamins relationship.

VI. Vitamins

1. Organic in nature;

2. Dietary requirements of one or more species;

3. Necessary in small amounts;

4. Effective for metabolic activity but are not found in the structure portion of the body.


1. Fat soluble (ADEK);

2. Water soluble (Thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, choline, folic acid, & B12;

3. Isositol, paraamino-benzoic acid (PABA), and Vitamin C.

Table 1-1

Animal Mineral


Major Function

Same Deficiency Symptoms

Major Interrelationships: Toxicities

Good Sources for Animals


Major or macro minerals:



Major cation in osmotic pressure and acid-base balance in body fluids, upon which depends the transfer of nutrients to the cells and the removal of waste materials and the maintenance of water balance among the tissues.

Associated with muscle contraction.

Important in making bile.

Reduced growth and efficiency of feed utilization in growing animals, reduced milk production and weight loss in adults.

Lowered reproduction (infertility in males. and delayed sexual maturity in females).

Craving for sodium. evidenced by such things as drinking urine.

In laying hens, a deficiency of sodium results in lowered production. loss of weight, and cannibalism.

Salt toxicity, which is accentuated with restriction of water intake, readily occurs in nonruminants. It is characterized by a staggering gait: blindness, and other nervous disorders.

Excess Na results in hypertension.

Salt; free-choice, or added to the ration at a level of 0.25-0.50%

The body contains approximately 0.2% sodium.



Major anion involved in osmotic pressure and acid-base balance (chloride shift).

Chief anion of gastric juice where it unites with H ions to form hydrochloric acid.

Depressed growth rate.

Chicks on Cl-deficient diet exhibit nervous symptoms induced by sudden noise.

Excess Cl is not likely.

Salt: free-choice. or added to the ration al a level of 0.25-0.50%.

In practice. Na and Cl are supplied together as common salt.

The body's requirement for Cl is approximately half that of Na



Bone and teeth formation: nerve function: muscle contraction: blood coagulation; cell permeability

Essential for milk production and for formation of egg- shell in poultry.

Rickets in young. Osteomalacia in adults.

Tetany (hypocalcemia). Milk fever in dairy cows is the classical example of Ca tetany.

Hens: Thin-shelled eggs. drop in egg production, and lowered hatchability.

Calcium-phosphorus ratio is important. For nonruminants, it should be 1:1-2:1. For ruminants, it may be anywhere from 1:1-7:1.

Vitamin D is involved. If adequate vitamin D is present. the ratio of calcium to phosphorus is less important.

Excess Ca reduces the absorption and utilization of Zn. In swine. this causes parakeratosis.

Excess Mg decreases Ca absorption, replaces Ca in the bone. And increases Ca excretion.



Dicalcium phosphate.

Defluorinated phosphate.

Protein supplements of animal origin. legume forages, and rape.


Bone meal.

Over 70% of the ash of the body consists of Ca and P.

Approximately 99% of the Ca of the body is present m the bones and teeth.

Calcium availability of 70% is generally assumed for ail feed- stuffs.

Phosphorus (P)

Bone and teeth formation: a component of phospholipids which are important in lipid transport and metabolism and cell-membrane structure.

In energy metabolism.

A component of RNA and DNA. the vital cellular constituents required for protein synthesis.

A constituent of several enzyme systems.

Rickets in young,

Osteomalacia in adults.

Depraved appetite(pica). but this is not specific for phosphorus deficiency.

Breeding problems.

Urinary problems.

Hens: Reduced egg production.

Ratio of Ca-P is important: somewhere between 1 -2 parts of Ca to 1 part of P.

Sufficient vitamin D is necessary For P assimilation and utilization.

Excess Ca and Mg cause decrease in P absorption.

In ruminants. excess P in relation to Ca is likely to cause calculi.

Monosodium phosphate.

Diammonium phosphate.

Dicalcium phosphate.

Defluorinated phosphate.

Bone meal.

Most cereal grains and their by products (notably wheat bran) are high in P.

Approximately 80% of the P of the body is present in the bones and teeth.

Excess P may result in lameness and spontaneous fracture of long bones.

High P has a laxative effect.



Essential for normal skeletal development. as a constituent of bone: enzyme activator, primarily in glycolytic system.

Helps to decrease tissue irritability.

Vasodilatation, with resulting reduction in blood pressure (manifested outwardly by a flushing of the skin).

Hyperirritability. Tetany (grass tetany, or grass staggers) characterized by loss of appetite, (anorexia). Hyperemia, convulsions, and death.

Excess of Mg upsets Ca and P metabolism.

Mg toxicity from feeding has not been demonstrated.

Magnesium sulfate or oxide, mixed with salt or small amount of feed.

Deficiencies of Mg may be encountered with suckling calves and pigs.

Potassium (K)

Major canon of intracellular fluid where it is involved in osmotic pressure and acid-base balance.

Muscle activity,

Required in enzyme reaction involving creatine.

Influences carbohydrate metabolism.

Growth retardation, unsteady gait. general muscle weakness, pica. diarrhea distended abdomen, emaciation followed by death.

Abnormal electro-cardiograms.

Magnesium deficiency, results in failure to retain potassium; hence. it may lead to K deficiency

Excessive levels of potassium interfere with magnesium absorption.

Potassium chloride.

Roughages usually contain ample potassium.

Potassium deficiency may occur in drylot finishing cattle or sheep on a high concentrate ration.

Sulfur (S)

Required as a component of sulfur- containing amino acids cystine and methionine.

As a component of biotin. sulfur is important in lipid metabolism.

As a component of thiamin, it is important in carbohydrate metabolism.

As a component of coenzyme A. it is important in energy metabolism.

Retarded growth, primarily due to not meeting the sulfur amino acid requirement for protein synthesis.

Sheep fed nonprotein N to replace protein without S supplementation show reduced wool growth (wool contains approximately 4% sulfur).

Sulfur is related to the amino acids cystine and methionine, and to biotin, thiamin, and coenzyme A (see column to left. "Major Functions").

Sulfur toxicity is not a practical problem.

Nonruminants should be provided sulfur-containing proteins.

Ruminants and horses may be provided sulfur in protein. as elemental sulfur or as sulfate sulfur.

The body contains approximately 0.15% sulfur.

Sulfur requirements are primarily those involving amino acid nutrition.

Ruminants fed urea as a source of protein nitrogen may benefit from supplemental sulfur.

Trance or micro minerals:




Insulinlike effect in glucose metabolism (shown in the rat),


There is no evidence that practical animal rations need to be supplemented with Cr.

The importance of Cr in glucose metabolism of other animals(other than the rat) and man has not been established to date.



As a component of vitamin B12.

Rumen microorganisms use Co for the synthesis of vitamin B12 and the growth of rumen bacteria.

Deficiency of Co in cattle and sheep produces symptoms similar to a deficiency of vitamin B12.

Related to vitamin B12.

Cobalt toxicity is not likely

Cobaltized mineral mixture made by adding Co at rate of 0.2 oz/100 lb of salt as cobalt chloride, cobalt sulfate. Cobalt oxide. or cobalt carbonate. Also. several good Co- containing commercial minerals are on the market.

Grazing animals may be given pellets composed of cobalt oxide and iron administered orally with a balling gun. The pellets lodge in the rumen and are gradually dissolved over a period of months.

The Co content of the leaves of the catalpa tree is regarded as a good indicator of the adequacy of cobalt in an area.

Co-deficient areas have been reported in Australia, western Canada. and in the U.S. in the states of Florida. Michigan, Wisconsin, Massachusetts. New Hampshire, Pennsylvania, and New York.


Co-deficient areas show loss of appetite. reduced growth, and loss in body weight, followed by emaciation, anemia. and eventually death. Frequently a depraved appetite is noted.

The disease called " salt sick'' in Florida is due to Co deficiency associated with Cu deficiency.

In different pans of the world, Co deficiency is known as Denmark disease. coast disease. enzootic marasmus, bush sickness, wasting disease, Nakuritis, and pining disease.




Along with iron and vitamin B12, copper is necessary for hemoglobin formation. although it forms no pan of the hemoglobin molecule (or red blood cells).

Essential in enzyme systems, hair development and pigmentation, bone development, reproduction, and lactation.

Fading hair coat: light wool growth and straight, hair-like fibers, known as steely wool.

Nervous symptoms. known as ataxia.

Lameness, swelling of joints. and fragility of bones.

Nutritional anemia, commonly called ''salt sick.''

An excess of molybdenum in the presence of sulfate causes a condition which can be cured by administering copper.

Excess copper (levels above 250 ppm) is toxic: it accumulates in the liver, and death may result.

In high-molybdenum areas, the Cu level for horses and cattle should be about 5 times higher than normal.

Trace mineralized salt containing copper sulfate or copper carbonate.

Any mineral mix containing copper must be thoroughly mixed in order to prevent copper toxicity or poisoning.

A variable store of copper is located in the liver and spleen.

Milk is low in Cu: hence. young animals raised almost exclusively on milk may develop anemia.

The soils of Florida and the Coastal Plain region are copper deficient.

Copper deficiencies are common in Australia.



Protects against dental canes (tooth decay) in children, and possibly in other animals, also.

Excesses of fluorine are of more concern than deficiencies in livestock production.

High dietary Ca depresses F uptake of bone.

F is a cumulative poison: hence. the toxic effects may not be noticed for some time.

High levels result in enlarged bones: softening. mottling. and irregular wear of the teeth: roughened hair coat: delayed maturity; and less efficient utilization of feed.

No need to supplement livestock with fluorine has been demon strafed. Should such supplementation be necessary. 1 ppm in the drinking water should suffice.




Needed by the thyroid gland for making thyroxin, an iodine- containing hormone which controls the rate of body metabolism or heat production.

Goiter (big-neck) in humans, calves, lambs. and kids: stillbirths and weak young: hairless pigs woolless lambs at birth.

There is no satisfactory treatment for animals that have developed pronounced I-deficiency symptoms.

Iodine deficiency in young animals is called cretinism. In adults it is known as myxedema.

Long-term chronic intake of large amounts of I reduces thyroid uptake of I.

Marked species differences exist in tolerance to high intakes of I.

Stabilized iodized salt containing 0.01% potassium iodide (0.0076% I).

Calcium iodate.

Ethylenediamine dihydriodide (EDDI).

Enlargement of the thyroid gland (goiter) is nature's way of trying to make enough thyroxin (an I-containing hormone) when there is insufficient I in the feed.

Mature animal body contains less than 0.00004% I.

I deficiencies are world wide, In the U.S the Northwest. the Pacific Coast. and the Great Lakes regions are goner areas.



Iron is a constituent of hemoglobin, the iron-containing compound that transports oxygen.

Also, iron plays a role in cellular oxidations, being a component of certain enzymes concerned with oxygen transfer.

Fe-deficiency anemia, characterized by smaller than normal number of red cells and less than normal amount of hemoglobin.

Iron is related to hemoglobin.

Cu is required for proper Fe metabolism.

Pyridoxine deficiency decreases the absorption of Fe.

Too much iron may be deleterious-interfering with phosphorus absorption by forming An insoluble phosphate.

Ferrous sulfate administered orally, or iron dextran injection.

Leafy portions of plants. meats, legume seeds. cereal grains, and cane molasses.

Trace mineralized salt.

The body contains only about 0.004% iron. Thus, a mature human contains only about 1/10 ounce of this mineral.

Iron is stored in the liver. spleen. and kidneys.

Young animals are born with a store of iron. But. milk is low in iron. So. when young animals are continued on milk for a long time, particularly under confined conditions and with little or no supplemental feed. nutritional anemia will likely develop.



Essential for normal bone formation (as. a component of the organic matrix).

Thought to be an activator of enzyme systems involved in oxidative phosphorylation, amino acid metabolism. fatty acid synthesis. and cholesterol metabolism.

Growth and reproduction.

Poor growth.

Lameness, shortening and bowing of the legs, and enlarged joints.

"Knuckling over'' in calves.

Impaired reproduction (testicular degeneration of males: defective ovulation of females).

Slipped tendons(perosis) in poultry.

Excess Ca and P decreases absorption.

Mn is not toxic in moderate excesses.

Trace mineralized salt containing 0.25% manganese(or more).




As a component of the enzyme xanthine oxidase-especially important in poultry for uric acid formation.

Stimulates action of rumen organisms.

Toxic levels of Mo are of greater practical concern than deficiencies.

Mo is related to uric acid formation in poultry and microbial action in ruminants.

Mo as a toxic mineral affects cattle and sheep grazing pastures grown on soils high in Mo content.

Toxic levels of Mo interfere with copper metabolism: hence. Increase copper requirements.

No Mo supplementation of normal rations is necessary.

Mo toxicity results in severe scours and loss of condition.



Not completely known. But involved in vitamin E absorption and, or retention. Also. a required nutrient in its own right. Se prevents degeneration and fibrosis of the pancreas in chicks,

Implicated with glutathione peroxidase.

Nutritional muscular dystrophy in lambs and calves.

Exudative diathesis in poultry.

Liver necrosis in pigs.

Selenium is related to vitamin E absorption.

Animals consuming forage or grain produced on seleniferous soils develop blind staggers or alkali disease, characterized by emaciation. loss of hair. soreness and sloughing of hooves, lameness, anemia, excess salivation, grinding of the teeth. Blindness, paralysis. and death.

In poultry, egg production and hatchability are reduced and deformities are common. including lack of eyes and deformed wings and feet.

High-protein rations tend to protect against Se toxicity.

In 1974. FDA approved the addition of Se in either sodium selenite or sodium selenate at rate of 0.1 ppm to complete rations for swine, growing chickens to 16 weeks of age. breeder hens producing hatching eggs, and nonfood animals. and a: rate of 0.2 ppm in complete rations for turkeys.



Involved in the mineralization process in bones.


From a practical stand- point. adverse effects of high-Si intake rather than Si deficiency appear to be of concern.

Urinary calculi may develop upon excessive intake of silicon

of the most abundant elements on earth. Present in large amounts in soils and plants

On purified diets. The addition of Si has increased the growth rate of chicks and rats

Zinc (Zn)

Needed for bone and feather development.

Zinc is a component of several enzyme systems. including carbonic anhydrase.

Also. Zn is required for normal protein synthesis and metabolism

Loss of appetite and stunted growth.

Poor hair or feather development: slip- ping of wool.

Rough and thickened skin in swine. known as parakeratosis.

Excess Ca reduces the absorption and utilization of Zn. Precipitating parakeratosis in swine.

Excess Zn interferes with Cu metabolism and may cause anemia.

Zinc carbonate

Zinc sulfate

Zinc imparts "bloom'' to the hair coat

Table 1-2

Animal Vitamin Chart

Name of Vitamin

Animals Most Affected


Some Deficiency Symptoms

Good Sources for Animals


The fat-soluble vitamins:




Affects all farm animals, including poultry.

Bone growth.

Night vision (formation of visual purple in the eye).

Epithelial tissue main tenance-respiratory, urogenital and digestive tracts, and the skin.

Stunted growth or loss of weight and loss of appetite, xerophthalmia (an eye disease), night blindness. nervous incoordination as shown by a staggering gait, and sterility. in males and females or young which are born weak or dead.

Reproductive failure.

Hydroencephaly in young rabbits born to deficient females.

Chicks: Wobbly gait.

Hens: Reduced egg production and hatchability.

Vitamin A can be provided as the synthetic vitamin or as its precursor. carotene Rich sources of carotene follow:

Green, leafy hays, not over 1 year old.

Grass silages.

Lush, green pastures.

Yellow corn.

Green and yellow peas.

Fish oils.


Whole milk.

Dehydrated alfalfa meal.

Vitamin A is found only in animals: plants contain the precursor, carotene.

Animals are able to store considerable vitamin A, but because of their greater requirements and less storage, young animals suffer from a deficiency much sooner than those that are mature.

Both carotene and vitamin A are readily destroyed by oxidation, thus resulting in considerable losses in processing and storing(as in making or storing of hay).



Affects all farm animals, including poultry.

Aids in the assimilation and utilization of calcium and phosphorus and necessary in normal bone development of animals. including the bones of the fetus.

Rickets in young.

Osteomalacia in adults.

Chicks: Reduced growth, soft bones (rickets), leg deformities.

Hens: Poor eggshells and lowered hatch ability.

Vitamin D2 (irradiated ergosterol), the plant form.

Vitamin D3 the animal form.


Sun-cured hays.

Cod and certain other fish-liver oils.

Irradiated yeast.

Most mammals can use either D2 or D3 but birds require vitamin D3.

When animals are exposed sufficiently to direct sunlight. The ultraviolet light in the sunlight penetrates the skin and produces vitamin D3 from traces of 7 dehydrocholesterol in the tissues.

Tissue storage is very limited.

The vitamin D requirement is less when a proper balance of calcium and phosphorus exists.



Calves, sheep, horses, poultry, rats, and perhaps certain other animals.


Muscle structure.


Muscular dystrophy(stiff lamb disease and white muscle disease).

Reproductive failure.


Chicks: Encephalomalacia (crazy chick disease), exudative diathesis.

Hens: Poor hatchability.

Turkeys: Myopathy of the gizzard.


Germ or germ oils of plants.

Green plants.

Green hays,

Vitamin E is widely distributed in all natural feeds.

Utilization of vitamin E is dependent on adequate selenium.



Likely all species.

Essential for pro- thrombin formation and blood clotting.

Prolonged blood clotting time, generalized hemorrhages and death in severe cases.

Menadione (vitamin K3).

Green pastures.

Well-cured hays.

Fish meal.

In general. this factor is widely distributed in normal farm rations. Also, all classes of farm animals synthesize it.

Vitamin K has definite value in human therapy where clotting of the blood is impaired due to a deficiency of the vitamin.

Menadione is widely used commercially as a source of vitamin K.

Well known antagonists vitamin K are dicoumarol and warfarin.

The water-soluble vitamins:




Swine, rats, poultry, and man.

Ruminants synthesize B12 unless cobalt is deficient.

Coenzyme in several enzyme systems.

Closely linked with folic acid.

All animals show retarded growth

Pigs show uncoordinated hind leg movements; and there's reproductive failure in sows.

Eggs from B12 -deficient hens fail to hatch.

Synthetic B12 .

Protein supplements of animal origin.

Fermentation products.

B12 is apt to be lacking in swine and breeder poultry nations.


Required by all species.

Component of several enzyme systems.

Pigs exhibit spasticity of the hind legs, crack in the feet, and a dermatitis. There is also lowered efficiency of feed utilization.

Chicks and turkey poults show dermatitis and perosis.

Hens: Poor hatchability.

Synthetic biotin.

Yeast, milk, egg yolk, liver, and kidney are especially rich sources of biotin.

Ordinary farm rations probably contain ample biotin, or farm animals synthesize all they need.

Biotin is rendered unavailable by raw egg white.


Swine, rats, and poultry. Choline deficiency has not been observed in man.

Involved in nerve impulses.

A component of phospholipids.

Donor of methyl groups.

Fatty livers in most species.

Kidney hemorrhaging.

In swine. abnormal gait in growing pigs and reproductive failure in adult females.

In chicks. slipped tendon (perosis).

Choline chloride.

Choline content of normal feed is sufficient.

With a high-protein diet. enough choline is synthesized from certain precursor and amino acids. Deficiency symptoms are more readily obtained as the protein content is lowered.

Folic acid


All animals and birds may be affected.

Related to B12 metabolism.

Metabolic reactions involving incorporation of single carbon units into larger molecules.

Poor growth.

Macrocytic anemia.

Synthetic folacin.

Some animal proteins: well-cured, green leafy alfalfa; green pastures.

Folic acid is widely distributed in both plants and animals. It was given this name because of the abundance of the factor in plant leaves.


Not clearly established.

Not known.

Spectacled eye appearance in rats.

Synthetic inositol.

All feeds.

Widely distributed in animal feeds.

Synthesized in intestines.


(nicotinic acid)

It is a dietary essential of pigs, chickens. monkeys, and man.

Apparently synthesized in the digestive tract of ruminants (sheep and cattle) and the horse.

Constituent of coenzymes.

Hydrogen transport.

Reduced growth and appetite..

Swine exhibit diarrhea. vomiting, dermatitis, unthriftiness, and ulcerated intestine.

Synthetic niacin.

Animal by-products.

Green alfalfa is a fair source.

Niacin present in most cereal grains is not available to the pig and other simple- stomached animals

Niacin can be synthesized in the body from surplus tryptophan.

Mature ruminants do not need dietary niacin under most conditions because of synthesis of rumen microflora.


Chicks show poor feathering, scaly dermatitis, and sometimes, a "spectacled eye."

Dogs show a darkening of the tongue (black-tongue) and mouth lesions.

Man develops pellagra characterized by a bright red tongue, mouth lesions, anorexia, and nausea.


Pantothenic acid

Rats. dogs. pigs. chickens. and turkeys. Synthesized in rumen of cow and sheep: perhaps the horse also synthesizes it.

Component of coenzyme A. required for energy metabolism.

All species exhibit reduced growth. Loss of hair. and enteritis.

Calcium pantothenate.

Fish solubles.

Grain is very deficient in pantothenic acid.

Of all B vitamins. it is most likely to be deficient under drylot conditions.


Mature ruminants synthesize pantothenic acid in rumen. Signs of deficiency in calves are rough coat. dermatitis. anorexia, and loss of hair around eyes.

Pigs develop goose-stepping'' gait.

Chicks show dermatitis and embryonic death.

Dogs vomit and show fatty infiltration of liver.


Para-amino-benzoic acid

Essential growth factor for micro organisms.

Not clearly established.

Not demonstrated in animals.

Synthetic para-amino-benzoic acid.

Not well known.

Abundantly synthesized in intestines



B6 is a dietary essential for the rat. pig. chick. and dog. It is synthesized in the rumen of cattle and sheep and perhaps in the cecum of the horse: thus. No deficiency symptoms in these species have been reported.

As coenzyme in protein and nitrogen metabolism.

Involved in red blood cell formation.

Important in endocrine system.

All species exhibit convulsions.

Pigs show anorexia and poor growth.

Chicks show retarded growth and abnormal feathering.

Hens show lowered egg laying and hatch-ability.

Synthetic vitamin B6

Cereal grains and their by-products.

Rice bran and polished rice.

Green pastures.

Well-cured alfalfa hay.


Normally. animal rations are not lacking in vitamin B6.



Thought to be required by all animals. but deficiency symptoms not observed in ruminants. Perhaps due to rumen synthesis. Deficiency symptoms noted in poultry, swine, and horses.

Promotes growth and functions in the body as a constituent of several enzyme systems and as such is important in carbohydrate and amino acid metabolism.

Retarded growth in most species, with a wide variety of other symptoms somewhat variable with the species. Periodic ophthalmia (moon blindness) in horses: reproductive failure in the sow, and slow growth. anemia. Diarrhea, unthrifty appearance, eye opacities. and an abnormal gall in the young pig: and curled toe paralysis in birds.

Synthetic riboflavin.

Green pastures.

Well-cured, green. leafy hays.

Grass silage.

Milk and milk pro ducts.

Meat scraps and fish meal.

Grains are a poor source of riboflavin. Many common rations are borderline or deficient in riboflavin, especially swine and poultry rations.



All animals must have a dietary source, unless there is rumen synthesis. As in cattle and sheep.

As a coenzyme in energy metabolism.

Promotes appetite and growth, required for normal carbohydrate metabolism. aids reproduction.

Reduction in appetite(anorexia) and loss in weight.

Cardiovascular disturbances.

Lowered body temperature.

Chastek paralysis in mink and foxes.

Chicks: Polyneuritis (retraction of the head).

Hens: Lowered egg production.

Beriberi (in man).

Thiamin hydrochloride.

Green pastures.

Well-cured. green. leafy hays.

Cereals grains.


Brewers' yeast.

Seldom deficient in animals.

Some fish feeds possess an enzyme-thiaminase-which is antagonistic to thiamin.

Fats in particular have been shown to exhibit a thiamin-sparing effect.


C (ascorbic acid)

Dietary need is limited to man, the guinea pig. and the mom key. Probably required by other species but synthesized in the body.

Collagen formation.

Formation of the intercellular sub stances of the teeth, bones, and soft tissues, increases resistance to infection. promotes firm gums.

Scurvy: swollen, bleeding and ulcerated gums: loosening of teeth, and weak bones.

Ascorbic acid.

Citrus fruits.

Green pastures.

Well-cured hays.

Ordinary farm rations and body synthesis provide adequate vitamin C.