Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2005
Publication Date: July 24, 2005
Citation: Nielsen, F.H. 2005. The toxicity of minerals that may be advocated for animal health and production through reasons other than nutritional need [abstract]. Journal of Dairy Science. 88(Suppl. 1):333. Presented at ADSA-ASAS-CSAS 2005 Joint Meeting in Cincinnati, OH, July 24-28, 2005. Technical Abstract: There are several mineral elements that are unlikely to be of toxicological concern under natural conditions for domestic animals, but whose tolerable intake levels may become of interest because of possible exposure through supplements given with the intention of boosting performance. These elements include silicon as sodium zeolite A that can increase chicken egg shell thickness, prevent parturient paresis in dairy cows, and decrease bone-related injuries in horses; rare earth elements that have been reported to increase feed conversion and weight gain in beef cattle, sheep, pigs, rabbits, chickens and ducks, milk production of dairy cattle, egg production of hens, and the output, survival rate and feed conversion of grass carp and prawn; boron that may enhance immune function and bone strength in pigs; lithium that may be useful as a food aversion agent for grazing animals; and chromium that apparently improves carcass characteristics in swine, immune response in stressed animals, and milk production in dairy cows. The fact that these elements have beneficial effects at intakes higher than that found with normal diets makes it important to determine when these higher intakes become excessive and result in toxicosis. The maximal tolerable intake of these elements can be influenced by dietary composition because their mechanisms of toxicity include interference with the utilization of other essential minerals (lithium, silicon, rare earths), enzyme inhibition (boron), and oxidative stress (chromium). The predominant sign of toxicosis of these elements is reduced growth. Recommendations for the maximal tolerable levels of these elements for animal health and the rationale for the recommendations will be provided at the symposium.