2. What are vitamins
• Vitamins are tasteless organic substances that are
indispensable to the normal metabolic processes of
organisms. They are essential to maintain health and
performance, and have to be supplied with the feed.
• Vitamins do not provide energy themselves, but a
deficiency of any vitamin can cause serious symptoms.
3. History
• The term vitamin was coined by biochemist
Casimir Funk.
• In 1912 When scientists trying to isolate fat soluble
factor B, they discovered a substance containing
nitrogen which was chemically an amine, and which
was in therefore named vitamin (vita = life).
4. Classification of vitamins
There are two main groups of vitamins:
• Fat-soluble vitamins:
Fat-soluble vitamins have specific functions
in the development and maintenance of tissue structures.
• Water-soluble vitamins:
Water-soluble vitamins participate in
catalytic functions or act as control mechanisms in the
metabolism, e.g. as co-enzymes.
5. Fat soluble vitamins
• The vitamins A, D, E, K and ß-carotene (precursor of
vitamin A) belong to the fat-soluble vitamins.
• These are stored in the body for long periods of time
and generally pose a greater risk for toxicity when
consumed in excess.
• The sites of storage are inner organs such as the
kidneys and liver, the muscles, the brain and fat
tissue.
6. • In the small intestine, the fat-soluble vitamins are
transported into the intestinal cells as part of micelles.
• Once inside the intestinal cells, fat-soluble vitamins are
packaged with fat and other lipids into a chylomicron.
• The chylomicrons travel through the lymph system to
the main circulation.
• Excretion normally only occurs after transformation
during metabolism.
7. Vitamin A
• Vitamin A was discovered in 1909 in fish liver oil
• The term vitamin A refers to a family of fat-soluble
retinoids that include retinol, retinal, and retinoic acid.
• They contain a ring with a polyunsaturated fatty acid
tail. Attached at the end of the fatty acid tail is either an
alcohol group (retinol), an aldehyde group (retinal), or
an acid group (retinoic acid).
8. Vitamin A terms
• Retinoids The term used to describe the family of
preformed vitamin A compounds.
• Retinol The alcohol form of preformed vitamin A.
• Retinal The aldehyde form of preformed vitamin A.
• Retinoic acid The acid form of preformed vitamin A.
• Retinyl ester The ester form of preformed vitamin A
found in foods and stored in the body.
• Beta-carotene One of the provitamin A carotenoids.
9. Natural sources and bioavailability
• Vitamin A is found only in feeds of animal origin, e.g.
liver, fish oil and high-fat fishmeal
• Low in milk and eggs.
• Feeds of plant origin (grass, carrots) only contain ß-
carotene, a precursor that can be converted into
vitamin A.
• Conversion ratio of ß –carotene into vitamin A
depending on animal species
10. Species
Vitamin A per mg
beta Carotene
Conversion ratio
Dairy cows 370 IU 8–10 : 1
Fattening cattle 440 IU 7–8 : 1
Horses 420 IU 6–10 : 1
Sheep 480 IU 6–8 : 1
Pigs 510 IU 6–7 : 1
Poultry 1667 IU 2 : 1
11. Conversion of Vitamin A Compounds
Retinyl ester Retinol (alcohol form)
Retinoic acid Retinal (aldehyde form)
Beta-carotene
12. Metabolic Functions of Vitamin A
• Each form of retinoid plays a specific role in the body.
Retinal (the aldehyde form) participates in vision.
• The hormone like action of retinoic acid (the acid form)
is essential for growth and development of cells,
including bone development.
• Retinol (the alcohol form) supports reproduction and a
healthy immune system. In addition to these critical
roles, vitamin A may help prevent cancer.
13. Physiological role of vitamin A
• Formation, protection and regeneration of skin and
mucous membranes
• Promotion of fertility
• Control of growth and differentiation processes of the
cellular metabolism
• Increased resistance to infectious diseases
14. Interaction with other nutrients
Vitamins Synergistic to Vitamin A
• Vitamin E & Vitamin C : Due to their antioxidant
activity. And vitamin E aids in stabilization of cell
membranes.
• Vitamin B6 : Because of its synergistic effect upon the
mineral zinc.
• Besides B6, vitamin B1, B2, B3, and B5 have been
specifically described as vitamin A synergists.
15. Vitamins Antagonistic to Vitamin A
• Fat soluble vitamins compete for absorption and transport
so all other fat soluble vitamins are antagonistic In nature.
• Vitamin E : The antagonistic effects are also indicated by
the opposite effects on prostaglandin E1 and E2 (PGE2
PGE2) synthesis.
• Vitamin C : Due to its copper lowering effect, causes
oxidation of vitamin A by increasing tissue iron
accumulation.
• Vitamin B1, B12, B6.
16. Minerals Synergistic to Vitamin A
• Zinc : Required for the mobilization of vitamin A from
liver. Zinc is involved in maintaining the plasma retinal
binding protein (RBP), a specific transporter for vitamin
A.
• Iron : Vitamin A facilitates the mobilization of stored
iron for incorporation into erythrocytes.
• Selenium : Involved in antioxidant activity.
• Magnesium, Manganese, Potassium, and Phosphorus.
17. Minerals Antagonistic to Vitamin A
• Iron : Excessive tissue causes destruction by
peroxidation.
• Selenium : Though selenium is an antioxidant, in large
amounts it acts as a pro-oxidant.
• Iodine : In the form of T4, although synergistic to
vitamin A, is antagonistic as well.
• The minerals copper, calcium, and sodium can have an
indirect antagonistic effect upon vitamin A due to their
interrelationship with the thyroid gland
18. Requirements
• For dogs and cats (RE Per Kg of feed 1 RE=40,000 IU)
• For Sheep and Goat (IU Per Kg of feed)
Species Weaning(RE) Adult(RE)
Peak
lactation(RE)
Dog 1515 1515 1515
Cat 1000 1000 2000
Species
Growing
lambs/Kids
Growing
ewes
Lactating
ewes
Sheep 1567 3305 2667
Goat 1530 1530 1532
19. • For Cattle (IU Per Kg feed)
• For Chicken (IU Per Kg feed)
1500 (for all types)
Type Feedlot Cattle
Pregnant heifer &
cow
Lactating cow
Beef 2200 2800 3900
Type
Lactating
cows
Fresh cows
Dry pregnant
cows
Growing
pregnant
heifers
Dairy 2123-3685 3490-5540 5576-8244 6486-7075
20. Deficiency symptoms
• Cornification of skin and mucous membranes.
• Retarded maturation of the ova and embryo mortality.
• Increased risk of infections.
• Nervous lesions.
• Night blindness.
• Xeropthalmia.
21. • In commercial supplement of vitamin A The active
substance of these products is vitamin A acetate.
The standard vitamin A content is normally 500 000 IU/g.
Excretion:
Most in urine as Oxo retinoic acid, small amounts in
expired air, some in feces.
Toxicity:
Birth defects, Central nervous disorders, Liver
abnormalities, Loss of bone density.
22. Vitamin D
• Vitamin D3 was discovered in 1918 in fish liver oil
• Vitamin D (calciferol) is called the “sunshine vitamin”
because it is derived from the reaction between
ultraviolet (UV) rays and a form of cholesterol found in
the skin.
23. • Vitamin D is found in two forms.
• Cholecalciferol or vitamin D3 is the form produced in
the skin and found in animal foods.
• Ergocalciferol or vitamin D2 is found in plants and
dietary supplements.
• Ergocalciferol and Cholecalciferol differ chemically in
the structure of their side chains.
24. Natural sources and bioavailability
• Vitamin D is found in very few products, e.g. as vitamin
D3 (Cholecalciferol) in whole milk and liver oils, and as
vitamin D2 (Ergocalciferol) in sun-dried green forage.
• Vitamin D2 is formed under the influence of UV
radiation from ergosterol in plants when they are
dried. Vitamin D3 is formed in the epidermis from 7-
dehydrocholesterol by UV radiation (exceptions: dogs,
cats).
25. Metabolism of Vitamin D
7-dehydrocholesterol Previtamin D3
Calcidiol Cholecalciferol
Calcitriol
26. Physiological role of vitamin D
• Vitamin D3 has no direct metabolic activity 1,25-
dihydroxyvitamin D3 is the form with the largest
biological effect.
• It regulates calcium and phosphate absorption and
metabolism and controls blood pressure.
• It promotes germ cell production
• It increases the performance of the immune system,
and inhibits auto-immunisation.
27. Interaction with other nutrients
• Magnesium : It activate vitamin D into a biologically
active form, and required to maintain calcium in the
body and is essential for bone health.
• Vitamin K : It helps in calcium absorption from foods.
And also helps in strengthening of bones.
• Zinc : Hepls in absorption of vitamin D into the cells.
• Boron : Hepls in absorption of Ca by bones.
28. • Vitamin A : Vitamin A and vitamin D work together for
animal health.
• Calcium : Low levels of vitamin D causes decreased
calcium absorption.
• Phosphorus : Ca and P ratio is important for vitamin D.
• Vitamin E : May cause vitamin -D dependent bone
mineralization problems.
29. Requirements
• For dogs and cats (RE Per Kg of feed 1 RE=40,000 IU)
• For Sheep and Goat (IU Per Kg of feed)
Species Weaning(RE) Adult(RE)
Peak
lactation(RE)
Dog 13.8 13.8 13.8
Cat 5-6 7 7
Species
Growing
lambs/Kids
Growing
ewes
Lactating
ewes
Sheep 84 98 67
Goat 136 136 136
30. • For Cattle (IU Per Kg feed)
• For Chicken (IU Per Kg feed)
200 (for all types)
Type Feedlot Cattle
Pregnant heifer &
cow
Lactating cow
Beef 275 275 275
Type
Lactating
cows
Fresh cows
Dry pregnant
cows
Growing
pregnant
heifers
Dairy 600-685 951-1511 1520-2249 804-858
31. Deficiency symptoms
• Disorders of calcium and phosphate metabolism.
• Rickets in young animals & Osteomalacia in adults.
• Extraction of mineral substances from the bones.
• Deformed bones and joints (softening of the bones).
• Growth disorders.
• Spontaneous bone fractures.
• Poor eggshell stability.
32. • Commercial supplement of vitamin D formulations
normally have a vitamin D3 content of 500 000 IU/g.
Toxicity
kidney damage, Nausea, Weakness, Disorientation.
Excretion
• Bile > feces > urine
33. Vitamin E
• Vitamin E was discovered 1922 in wheat germ oil.
• There are eight different forms of naturally occurring
vitamin E, but one form, alpha-tocopherol (α-
tocopherol), is most active in the body with a side
chain of saturated carbons.
34. Natural sources and bioavailability
• Grass, clover, alfalfa, green meal and uncrushed
oilseeds are rich in vitamin E.
• Humidity and long storage have an adverse effect on
vitamin E stability and content.
• Cereals and middlings mainly contain Beta, gama and
delta tocopherols (70–90%) with a biological activity
significantly lower than that of alpha tocopherol.
35. Physiological Role
• Reduces the production of lipid peroxyl radicals from
highly unsaturated fatty acids.
• Antitoxic effect in cell metabolism.
• Reduces the incidence of liver necrosis and muscular
degeneration.
• Antioxidant effect and .
• Stabilization of fat (protection against oxidation) in
animal products (meat, milk, eggs).
36. • Controls metabolism of the hormones via the anterior
lobe of the hypophysis.
• Maintains membrane stability, especially of the cardiac
and skeletal muscles.
• Controls the development and function of the gonads.
• Stimulates antibody production, phagocytosis and the
bactericide effects of phagocytes.
• Protection against abortion.
37. Interaction with other nutrients
Nutrients Synergistic to Vitamin E
• Selenium : Function closely linked to vitamin E (needed
for GSH peroxidase).
• Vitamin C : Helps in anti oxidant property.
• Sulfur containing amino acids.
38. Nutrients antagonistic to Vitamin E
• Vitamin A : Vitamin E Inhibits carotene absorption and
conversion to retinol.
• Vitamin K : May impair absorption.
• May cause vitamin -D dependent bone mineralization
problems.
39. Requirements
• For dogs and cats (mg Per Kg of feed)
• For Sheep and Goat (IU Per Kg of feed)
Species Weaning(mg) Adult(mg)
Peak
lactation(mg)
Dog 30 30 30
Cat 38 38 31
Species
Growing
lambs/Kids
Growing
ewes
Lactating
ewes
Sheep 15 15 15
Goat - - -
40. • For Cattle (IU Per Kg feed)
• For Chicken (IU Per Kg feed)
10-5 (for all types)
Type Feedlot Cattle
Pregnant heifer &
cow
Lactating cow
Beef - - -
Type
Lactating
cows
Fresh cows
Dry pregnant
cows
Growing
pregnant
heifers
Dairy 16-27 39-35 81-120 80-113
41. Deficiency symptoms
• Damage to cardiac and skeletal muscles (dystrophy,
myopathy)
• Sudden death through damage to the heart muscle
(mulberry heart disease)
• Liver lesions and changes in fat deposits (yellow-fat
disease in mink, brown coloration of bacon).
• Locomotory disorders and muscle incurvation (banana
disease) in pigs.
42. • Stiff lamb disease and White muscle disease due to
dystrophic alteration in calves and lambs.
• Fertility disorders
• Changes in the vascular and nervous system.
• Exudative diathesis.
• Nutritional encephalomalacia.
• Reduced hatchability and exudative diathesis
(increased plasma secretion of the blood) in poultry.
43. Toxicity
• There isn’t any known risk of consuming too much
vitamin E from natural food sources.
• Because vitamin E can act as an anticoagulant and
interfere with blood clotting, excess amounts in the
body increase the risk of hemorrhage.
44. Vitamin K
• Vitamin K was discovered in 1929 in alfalfa
Natural sources and bioavailability
• Vitamin K is a generic term for vitamin K1
(phylloquinone), K2 (menaquinone) and K3 (menadione).
• Green plants are rich in vitamin K1, Vitamin K2 is
produced by bacteria in the rumen and in the large
intestine.
45. • Vitamin K3 (menadione) is an industrial form.
• The fat-soluble forms K1 and K2 can only be absorbed
when pancreas lipase and bile acid are secreted.
• This is not necessary for the water-soluble vitamin K3.
• All three forms serve as a basis for the production of
menaquinone-4, which is highly active in the
metabolism.
46. Physiological role
• Synthesis of blood coagulation factors II (pre-
thrombin), VII, IX and X.
• Production of the calcium transport protein
osteocalcin for bone mineralization Participation in
carboxylation of other proteins.
47. Interaction with other nutrients
• Vitamin A & Vitamin E : May reduce the absorption of
Vitamin K.
• Vitamin E : interfere with blood clotting mechanism of
Vitamin K.
48. Requirements
• For dogs and cats (mg Per Kg of feed)
• For Cattle (IU Per Kg feed)
• For Chicken (IU Per Kg feed) 0.5 (for all types)
Species Weaning(mg) Adult(mg)
Peak
lactation(mg)
Dog 1.64 1.63 1.60
Cat 1 1 1
Type
Lactating
cows
Fresh cows
Dry pregnant
cows
Growing
pregnant
heifers
Dairy 2200 2200 2200 2200
49. Deficiency symptoms
• Hemorrhages in various tissues and organs.
• Blood coagulation disorders.
• Growth disorders.
Antagonists
• Dicoumarol.
• Coumarin derivatives.
• Sulphonamides.
• Mycotoxins.
50. Commercial supplement of vitamin K
Vitamin K3 is offered in three different product forms:
1. Menadione sodium bisulphite (MSB), with a minimum
content of 50% menadione
2. Menadione pyrimidinol bisulphite (MPB), with a
content of approx. 23% or 43% menadione
3. Menadione nicotinamide bisulphite (MNB), with a
content of 23% or 43% menadione and 16% or 31%
nicotinamide
51. Toxicity
• Occurs rarely.
• Vitamin K, excessive amounts can cause the breakdown
of red blood cells and liver damage.
