The organization and daily routine of a wagon train depended on the danger expected from the Native American tribes into whose territory it had traveled, the terrain, and the size of the caravan. Mormon trains, in particular, had a semi military formation.
Side effects. Taken at normal doses, selenium does not usually have side effects. An overdose of selenium may cause bad breath, fever, and nausea, as well as liver, kidney and heart problems and other symptoms. At high enough levels, selenium could cause death.
Selenium, in conjunction with vitamin E, is necessary for proper immune system function and to protect the integrity of cell membranes. However, a delicate balance exists between too little selenium and too much. In many areas of the country, horses ingest sufficient selenium while foraging, but in other areas, selenium needs to be part of the horse's diet.