Article Text

Pyrrolizidine alkaloid poisoning of yaks: identification of the plants involved
  1. H Winter,
  2. AA Seawright,
  3. HJ Noltie,
  4. AR Mattocks,
  5. R Jukes,
  6. K Wangdi and
  7. JB Gurung
  1. University of Queensland, Department of Veterinary Pathology, Brisbane, Australia.


A search was undertaken in the most eastern part of the Himalayan kingdom of Bhutan for the plants which are causing severe losses of yaks due to pyrrolizidine alkaloid poisoning. Two Senecio and three Ligularia species were found on yak pastures at altitudes between 3000 and 4000 m, including one so far underscribed Ligularia species. None was previously known to contain pyrrolizidine alkaloids. Another Senecio species was found between 2500 and 3000 m, an altitude too low for yaks to be kept but significant for other cattle. The search was supported by field chemical tests for the alkaloids and the diagnosis was later confirmed by thin layer chromatography and high pressure liquid chromatography. Two of the Senecio species had exceptionally high concentrations of pyrrolizidine alkaloids of about 0.5 per cent in the dry matter.

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.