Improved nutritional quality of animal products through manipulations of trace element and calcium status.

摘要

Research on the requirements and metabolism of trace elements in grazing livestock is revealing new ways in which the nutritional status of people might be improved. Our understanding of how to manage the mineral status of cattle and sheep can create additional impact through enhancing the quality and value of milk and meat. For example, by optimizing the familiar selenium and iodine supplementation strategies used to prevent deficiencies and maintain animal mineral requirements, we can tailor theelement content of the resulting animal products. Simple Se and I supplementation produces commensurate increases in milk and meat, but the concentrations of calcium and iron are not so easily manipulated, so other smarter strategies are called for. Forthese four nutritionally essential elements, maximum concentration and bioavailability to humans is affected by age of animal, stage of lactation, plus element chemical form and distribution among the milk and meat fractions.