Vitamin B12

Cyanocobalamin, or B12, is available in crystalline form, but this vitamin is essentially devoid in plant-source feed ingredients, existing instead in animal-source proteins and fermentation products, where it is considered (but not proved) to be 100% available.

Both animal- and fermentation-based feedstuffs contain Bi2 as methylcobalamin or adenosylcobalamin, which are bound to protein. As in humans, but unlike in sheep and horses, an intrinsic factor is required for gut absorption of B12 in swine and poultry. Crystalline vitamin B12 is considered quite stable in feeds and premixes.[2]

1. Zhuge, Q.; Klopfenstein, C.F. Factors affecting storage stability of vitamin A, riboflavin and niacin in a broiler diet premix. Poult. Sci. 1976, 65, 987.

2. Baker, D.H. Vitamin Bioavailability. In Bioavailability of Nutrients for Animals: Amino Acids, Minerals, and Vitamins; Ammerman, C.B., Baker, D.H., Lewis, A.J., Eds.; Academic Press, Inc.: San Diego, CA, 1995.

3. Buenostro, J.L.; Kratzer, F.H. Use of plasma and egg yolk biotin of white leghorn hens to assess biotin availability from feedstuffs. Poult. Sci. 1984, 63, 1563.

4. Emmert, J.L.; Garrow, T.A.; Baker, D.H. Development of an experimental diet for determining bioavailable choline concentration, and its application in studies with soybean lecithin. J. Anim. Sci. 1996, 74, 2738.

5. Bailey, L.B. Factors affecting folate bioavailability. Food 13. Technol. 1988, 42, 206.

6. Anonymous. Nomenclature policy: Generic descriptors and trivial names for vitamins and related compounds. J. Nutr. 14. 1979, 109, 8.

7. Czarnecki, G.L.; Halpin, K.M.; Baker, D.H. Precursor (amino acid):product (vitamin) interrelationship for grow 15. ing chicks as illustrated by tryptophan niacin and methio nine choline. Poult. Sci. 1983, 62, 371.

8. Oduho, G.; Han, Y.; Baker, D.H. Iron deficiency reduces the efficacy of tryptophan as a niacin precursor for chicks. 16. J. Nutr. 1994, 124, 444.

9. Baker, D.H.; Yen, J.T.; Jensen, A.H.; Teeter, R.G.; Michel, 17. E.N.; Burns, J.H. Niacin activity in niacinamide and coffee. Nutr. Rep. Int. 1976, 14, 115.

10. Oduho, G.; Baker, D.H. Quantitative efficacy of niacin sources for the chick: nicotinic acid, nicotinamide, NAD 18. and tryptophan. J. Nutr. 1993, 123, 2201.

11. Southern, L.L.; Baker, D.H. Bioavailable pantothenic acid 19. in cereal grains and soybean meal. J. Anim. Sci. 1981, 53, 403.

12. Sauberlich, H. Bioavailability of vitamins. Prog. Food Nutr. Sci. 1985, 9, 1.

Chung, T.K.; Baker, D.H. Riboflavin requirement of chicks fed purified amino acid and conventional corn soybean meal diets. Poult. Sci. 1990, 69, 1357. Gadient, M. Effect of Pelleting on Nutritional Quality of Feed. In Proc. of the Maryland Nutr. Conf.; 1986; p. 73.

Patel, K.; Baker, D.H. Supplemental iron, copper, zinc, ascorbate caffeine and chlortetracycline do not affect riboflavin utilization in the chick. Nutr. Res. 1996, 16, 1943.

National Research Council. Vitamin Tolerance of Animals; National Academy Press: Washington, DC, 1987. Yen, J.T.; Jensen, A.H.; Baker, D.H. Assessment of the concentration of biologically available vitamin B6 in corn and soybean meal. J. Anim. Sci. 1976, 42, 866.

Gregory, J.F., III; Kirk, J.R. The bioavailability of vitamin B6 in foods. Nutr. Rev. 1981, 39, 1. Baker, D.H.; Edwards, H.M., III; Strunk, C.S.; Emmert, J.L.; Peter, C.M.; Mavromichalis, I.; Parr, T.M. Single versus multiple deficiencies of methionine, zinc, ribo flavin, vitamin B 6 and choline elicit surprising growth responses in young chicks. J. Nutr. 1999, 129, 2239.

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