Vitamins

Lecture 6

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.

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

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

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.

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%.

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.

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

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.

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.