International effort assists dairy research

A plant toxins expert from Iran is assisting CSIRO Livestock Industries' scientists in their search for the cause of a liver disease afflicting dairy cattle in southern Australia.

Dr Reza Aslani - from the School of Veterinary Medicine at the Ferdowsi University of Mashhad - has been investigating the cause of acute bovine liver disease during a six-month sabbatical with the plant toxins research group at CSIRO's Australian Animal Health Laboratory in Geelong.

Although acute bovine liver disease appears to be associated with the native grass Cynosurus echinatus (Rough Dogs Tail), the true culprit remains elusive.

In collaboration with CSIRO scientists, Dr Aslani has been studying a fungus isolated - by Dr Ian Pascoe of the Department of Primary Industries, Victoria - from pasture species collected in paddocks where afflicted animals have grazed.

"The research involves exposing cultured cells to the fungus and looking for any changes," Dr Aslani says. "We have been fractionating and purifying extracts of the fungus to see if it can produce the hepatotoxins that cause acute bovine liver disease."

CSIRO plant toxins research group leader, Dr Steve Colegate, says the disease causes jaundice, photosensitisation and sudden death in cattle over six months of age and has afflicted animals in southwest Victoria, Tasmania, Western Australia, and southeast South Australia.

Identification of the toxin source is crucial for effective management of the disease.

"If we can identify the source, more effective management advice can be provided to producers, preventing exposure to the toxins and the consequent loss of stock and production," Dr Colegate says.

Dr Aslani is a clinical veterinarian with extensive experience in dealing with plant-associated intoxication of livestock.