Influence of time of exposure to high levels of minerals on the susceptibility of chicks to Salmonella gallinarum.

Mercury, 500 ppm; cadmium, 100 ppm; vanadium, 25 ppm; copper, 1,000 ppm; or selenium, 20 ppm were fed to chicks for various times before and after inoculation with S. gallinarum. These levels have been found to be toxic to chicks as indicated by reduced growth. When the feeding of the elements was discontinued at the time of inoculation, early mortality was increased but the effects tended to diminish as the experiment progressed. The elements had no effect on mortality if the feeding was discontinued 1 week before inoculation. When the elements were fed starting at the time of inoculation, both early (1 week post inoculation) and final mortality were increased. Delaying the administration of the elements for 2 days after inoculation resulted in no effect on mortality 1 week after inoculation but there were increases in final mortality when mercury, cadmium or selenium were fed.