Poultry vitamin requirements

Requirements of poultry for vitamin D are expressed ia iatematioaal chick units (ICU) which are based on the activity of vitamin in chick bioassays. ... 

Historically, rickets prevention or cure was used to evaluate adequate vitamin nutrient levels. More recendy, in the absence of uv light, Edwards (216) found different vitamin levels were required for the optimisa tion of the various effects of vitamin in poultry, ie, 275 lU/kg for growth, 503... 

The solution to the assay problem came from the fortunate finding by Mary Schorb, then working in the poultry industry, of a microorganism, Lactobacillus lactis dorner, which required vitamin B]2 for growth. With much quicker and more reliable assays the vitamin was isolated in 1948 in both the Merck and Glaxo laboratories. Its structure was determined by X-ray crystallography by Lenhert and Hodgkin (1961). 

Vitamin B12 is not found in plants. The primary source is microorganisms and the usual dietary sources for humans are meat and meat products (including shellfish, fish and poultry) and to a lesser extent milk and milk products. However, normally the microorganisms in the colon provide most of the requirement. 

Many species require vitamin K. The vitamin is frequently administered to poultry via feedstuffs. Intestinal bacteria, normally functioning, supply the vitamin to the human body. 

Like all other animals, poultry require five components in their diet as a source of nutrients energy, protein, minerals, vitamins and water. A nutrient shortage or imbalance in relation to other nutrients will affect performance adversely. Poultry need a well-balanced and easily digested diet for optimal production of eggs and meat and are very sensitive to dietary quality because they grow quickly and make relatively little use of fibrous, bulky feeds such as lucerne hay or pasture, since they are non-ruminants (have a simple stomach compartment). 

Cobalt is a component of the vitamin B12 molecule but a deficiency of cobalt has not been demonstrated in poultry fed a diet adequate in vitamin B12. Therefore, supplementation with this element is not normally necessary. Diets containing no ingredients of animal origin (which contain vitamin B12) contain no vitamin B12. Therefore, poultry fed on all-plant diets may require dietary cobalt, unless the diet is supplemented with vitamin B12. In practice, many feed manufacturers use a cobalt-iodized salt for all species since cobalt is needed in ruminant diets. This avoids the need to stock separate salt types for ruminant and non-ruminant diets and the inclusion of cobalt provides some insurance in case the poultry diet is lacking sufficient vitamin B12. 

Although vitamins are required in small amounts, they serve essential functions in maintaining normal growth and reproduction. Few vitamins can be synthesized by the bird in sufficient amounts to meet its needs. Some are found in adequate amounts in the feedstuffs commonly used in poultry diets, others must be supplemented. Although the total amount of a vitamin may appear to be adequate, some vitamins are present in bound or unavailable forms in feedstuffs. Supplementation is then essential. 

Poultry require 14 vitamins (Table 3.6), but not all have to be provided in the diet. Scott et al. (1982) have presented good descriptions of the effects of vitamin deficiencies in poultry. 

Poultry do not require vitamin C in their diet because their body tissues can synthesize this vitamin. The other vitamins must be provided in the diet in proper amounts for poultry to grow and reproduce. The egg normally contains sufficient vitamins to supply the needs of the developing embryo. For this reason, eggs are one of the best animal sources of vitamins in the human diet. 

Ascorbic acid (vitamin C) is a water-soluble vitamin but is not part of the B group. It is a metabolic requirement for all species but is a dietary requirement only for those that lack the enzyme for its synthesis (primates, guinea pigs, certain birds, fish). Therefore, it is not required in poultry diets. It is involved in the formation and maintenance of intercellular tissues having collagen or related substances as basal constituents. 

Nearly 80% of the soybean meal consumed in the United States is fed to nonruminants. Soybean meal is the most economic high-quahty protein available to feed manufacturers hence it assumes a dominant role (3, 4). Cereal-based rations for pigs and poultry may contain soybean meal as the only protein supplement, as a previous requirement for the inclusion of some animal or marine origin protein has been supplanted by the addition of lysine, methionine, and vitamin B12, where economics dictate (5). 

To help prevent vitamin D deficiency, most milk is now enriched with it. Other good sources of the vitamin are meat, poultry, fish, peanut butter, eggs, margarine, and liver, especially cod-liver oil. These sources exist in addition to the vitamin D produced naturally from exposure to sunshine. Unlike water-soluble vitamins, such as vitamin C, fat-soluble vitamins are stored in the liver and fat tissue and can become highly toxic if taken in excess. For these reasons, most nutrition experts do not generally recommend additional dietary supplements for vitamin D. Some individuals taking special medication for cholesterol, or who have dark sldn (which reduces the ability of sunshine to produce vitamin D), may require a diet rich in vitamin D or a supplement, see also Calcium Cholesterol. 

The Federal Enrichment Act of 1942 required the millers of flour to restore iron, niacin, thiamin and riboflavin lost in the milling process. Enriched flours and baked goods made from them are now excellent sources of niacin. Niacin may also be found in meat, poultry, fish, whole grains, and peanut butter. Besides direct niacin intake, humans can convert the amino acid tryptophan to niacin. Many people take daily vitamin supplements to ensure they get enough niacin and other essential nutrients, see also Coenzyme Nicotinamide Adenine Dinucleotide. 

Sources. Only bacteria can synthesize vitamin B12. Vitamin B12 is present in animal products such as meat, poultry, fish (including shellfish), and to a lesser extent milk, but it is not generally present in plant products or yeast. Fresh pasteurized milk contains 0.9 p.g per cup and is an important source of vitamin B12 for some vegetarians. Those vegetarians who eat no animal products need supplemental vitamin B12 to meet their requirements. 

For these reasons alone, a vitamin E symposium will not be short of problems and material for discussion. Many more unanswered questions come to light, however, when the biochemical and physiological properties of vitamin E are considered. The program of this meeting includes papers on the metabolism of vitamin E interrelations among vitamin E, metals, and ubi( uinones vitamin E and nucleic acid metabolism interrelations between vitamin E and polyunsaturated fatty acids vitamin E requirements of human infants vitamin E in health and disease of poultry, sheep, cattle, and pigs and so on. Everywhere, alongside established facts, there are unanswered questions and unsolved problems. 

Whitehead C C 1986 Requirements for vitamins. In Fisher C and Boorman K N (eds) Nutrient Requirements of Poultry and Nutrition Research, London, Butterworth, pp. 173 9. 

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