Mineralogy, microbial ecology, and mineral weathering in the subsurface are an intimately linked biogeochemical system. Although bacteria have been implicated indirectly in the accelerated weathering of minerals, it is not clear if this interaction is simply the coincidental result of microbial metabolism, or if it represents a speciŽ c strategy offering the colonizing bacteria a competitive ec...

and Implications Pre-ruminant Holstein bull calves were fed two diets of pasteurized whole milk (PWM) in amounts that either limited intake or that maximized intake according to common commercial practice. Diets then were either supplemented or not supplemented with a full complement of vitamins and trace minerals (VTM) that met or exceeded NRC requirements. The objective of the study was to qu...

Two hundred and sixteen weanling gilts (6.65+/-0.08 kg) were used to determine the effects of decreasing supplemental concentrations of Zn, Cu, Fe, and Mn, and trace mineral source (inorganic vs. chelated) on growth performance, mineral status, and fecal mineral concentrations from weaning through development. The study was conducted over three trials with 72 pigs in each trial. Gilts were bloc...

The early interest in selenium (Se) focused on its toxicity, but since 1957 it has been recognized as an essential dietary element. The diet is the major Se source and approximately 80% of dietary Se is absorbed, depending on the type of food consumed. In several regions of the world, the content of Se in diets has been estimated as insufficient. The dietary requirement for Se for most species ...

The fraction of population that is elderly has been increasing, as has the consumption of vitamin/trace mineral supplements, which is now a multibillion dollar industry. Yet the rationale for such supplement intake by the majority may be questioned. Some of the current recommendations for micronutrient intake by the elderly are extrapolations from recommendations made for younger adults, wherea...