1. Vitamins
Lecture 6

2. Vitamins
• Organic compound essential for health but
only in trace amounts (ppm).
• Required for normal growth and
maintenance of animal life.
• Function as catalyst
– Enzymes or coenzymes in metabolic processes.

3. Vitamin Supplementation
• Vitamin [ ] vary tremendously within
sources.
– In plants the source is affected by:
• Harvesting, processing and storage
• Species of plant
• Part of plant used
– In animal tissue the largest sources are:
• Liver
• Kidney

4. Vitamin Sources
• Vitamins are generally destroyed by Heat
– Exposure to air
– Sunlight
– Oxidizing conditions
– Storage conditions that allow mold growth
• Better to error on the positive side than have
a deficiency

5. Classification of Vitamins
• Water soluble
– B vitamins and Vitamin C
• B vitamins synthesized in rumen usually not needed
• Not stored in body so daily supply is needed if required.
– Enough found in feedstuffs
• Exception – Vit.B12 not found in plants
– Usually supplemented to ensure adequate amounts in
diet.
• Fat soluble
– A, D E and K
– May be stored in body so daily supply may not be
needed ?
– Vitamin Supplementation is very important in stressful
conditions.

6. Vitamin Sources
• Fat soluble vitamins – Vit. A
– Carotene
• Green and yellow plants Excellent source
• Betacarotene maybe important factor affecting reproduction in
high producing dairy cows.
– Vitamin A Acetate
– Vitamin A propionate
– Vitamin A palmitate
• Can be a problem after processing feed and
exposure to air.
– Pelleting can reduce vitamin A content up to 40%.

7. Vitamin Sources cont’d
• Vitamin A – antioxidants added to reduce storage
losses.
– Cost of Vitamin A is cheap therefore should be added
to diets to be safe.
• Vitamin D
– Ultraviolet rays activate a form of Cholesterol in an oil
on the skin and converts it to a form of Vit. D which is
absorbed.
– Important in the metabolism and absorption of Ca
– Present in D2 form in plants, D3 in animal products.
– Stable unless mixed with limestone or oxidizing
compounds- rapid loss in rations.

8. Vitamin Sources cont’d
• Vitamin K
– Synthesized and absorbed so efficiently almost
impossible to cause a deficiency.
– Essential for production or synthesis of prothrombin.
Related to blood clotting.
– Poultry is the only species that may require
supplementation.
• Vitamin E
– Primarily, alpha tocopherol present in most feedstuffs,
but highest in grem or germ oil of plants
(soybean,cottonseed, corn, etc.
– Antioxidant – inhibits or retard oxidation, reduce
hemolysis of RBC, stabilizes polyunsaturated fatty
acids
– Rapidly degraded in heat, light and high trace mineral
content of feed

9. General Rules of Vitamin
Supplementation
• Usually limiting in natural diets.
– Vitamin A, D, E, riboflavin, pantothenic acid,
niacin, choline, and B12
• Biotin may need supplemented in Poultry
and Swine.
• Vit. K synthesis may be inhibited by some
feed additives. However, produced by
microbes of the digestive tract.

10. Summary of Vitamins
• Supplementation is usually inexpensive
• Animals under stress - Vitamin requirements will
change. Vitamin A from 20 – 30,000 to 50,000 IU.
• Protect from the environment to reduce oxidation.
• Utilizes within a couple of days once mixed with
other feedstuffs.
• Look up specific requirement for the species you
are working with. Poultry usually require more
than four footed animals.