1. AAFCO (1998) Official publication of the association of American feed control officials incorporated. AAFCO, Champaign, pp 237–238
2. Ammerman CB, Baker DB, Lewis AJ (1995) Bioavailability of nutrients for animals. Academic, New York, pp 367–398
3. Ammerman CB, Henry PR, Miles RD (1997) Bioavailability of supplemental microminerals in the nutrition of pets. In: Proc. symp. nutrition and quality of life for companion animals. Roche Animal Nutrition and Health, Chicago, pp 1–17
4. Ansotegui RP, Bailey JD, Paterson JA, Hatfield PG, Swenson CK (1999) Effects of supplemental trace mineral form of copper status, estrus, ovulation rate, and fertility in beef heifers. Proc West Sec Anim Sci 50:189–192
5. Ashmead HD (1993) Comparative intestinal absorption and subsequent metabolism of metal amino acid chelates and inorganic metal salts. In: The roles of amino acid chelates in animal nutrition. Noyes Publishers, Norwich, pp 306–319