Alkaloids Toxic to Livestock

Authors: Molyneux, Russell; Panter, Kip

Submitted to: Book on Toxicology and Chemistry of Alkaloids
Publication Type: Book / Chapter
Publication Acceptance Date: 8/25/2009
Publication Date: 9/9/2009
Citation: Molyneux, R.J., Panter, K.E. 2009. Alkaloids Toxic to Livestock. In: Cordell, G.A. The Alkaloids: Chemistry and Biology Vol. 67. Elsevier, Amsterdam, The Netherlands. pp.143-216.

Interpretive Summary: This chapter describes plants containing toxic compounds that are responsible for poisoning of livestock in the United States and, to some extent, other parts of the world. Among these are poison hemlock, wild tobacco, , lupines, locoweeds, morning glories, groundsels, larkspurs, false hellebore and yew. The typical clinical signs of poisoning are described. Isolation and identification of the natural chemicals in these plants enables them to be tested for the specific way in which they produce the toxic effects. Although they are poisonous to animals if the levels are high enough, they can be to provide leads for potential new drugs, when used at lower levels. Observations of plant toxicity to animals can therefore be useful for treatment of human or animal diseases.

Technical Abstract: Alkaloids are a specific group of nitrogen-containing natural metabolites that enable plants to overcome temporary or continuous threats integral to their environment, while also controlling essential functions of growth and reproduction. These compounds are probably produced primarily to control fungal attack or competitive plant species. All of these roles are generally advantageous to the producing organisms but the inherent biological activity of such constituents often causes death, serious injury, or birth defects to non-target organisms that may be exposed to them, such as livestock. Chemical characterization of the alkaloids produced by various plant species, primarily in the western United States, has enabled correlation with specific toxic insult and clinical signs, so that careful observation may circumvent more serious consequences. Management plans can also be devised to prevent animal exposure to plants when the toxin levels are greatest. The primary alkaloid types and toxic plant species discussed are piperidine alkaloids in Conium maculatum (poison hemlock), piperidine and quinolizidine alkaloids of Lupinus species (lupines), polyhydroxy indolizidine and nortropane alkaloids of Astragalus and Oxytropis species (locoweeds) and Ipomoea species (morning glories), diterpene alkaloids of Delphinium species (larkspurs), and steroidal alkaloids of Veratrum californicum (Western false hellebore) and Taxus species (yews).