Is there a difference between exposures to one or two plant toxins?

Abstract Text: The majority of the plants in a given rangeland provide valuable forage for livestock species. However, plants that can poison livestock are very much a part of our rangelands. In this regard, most rangelands contain more than one poisonous plant. Frequently, much is known regarding the toxicity of individual plants and their effects on livestock. However, little is known regarding the effect of co-exposure to multiple toxic plants or even the effect of multiple toxins from an individual plant. Mixture toxicology, or the study of the co-exposure to multiple toxins, can result in additive, synergistic, or antagonistic effects. This presentation will highlight some of the recent research from the Poisonous Plant Research Lab wherein the effect of co-administering multiple plant toxins from the same plant and the effect of co-administration of different poisonous plants has been evaluated. A better understanding of the effect of co-exposure to multiple poisonous plants, and the mixture toxicology involved, will be useful in developing more beneficial management recommendations for ranchers.

Keywords: mixture toxicology, multiple toxins, poisonous plants, larkspur, death camas, methyllycaconitine, zygacine, sheep, cattle