Reducing Abortion in Cattle

Researchers at the University of Technology in Sydney are taking steps to solve the problem of a parasite that causes abortion in cattle, resulting in Australian dairy and beef industry losses of about $100 million p/yr.

The researchers are collaborating with NSW Agriculture to isolate the protozoan parasite Neospora caninum. Until now, N. caninum has only been isolated overseas. To develop a diagnostic blood test for use in Australia, researchers needed to isolate the Australian form of the parasite in case it differed from foreign types.

Cow herds infected with N. caninum can suffer abortion 'storms' at a rate of up to 30%, although usual losses are less than this. Abortions mean fewer calves, lower milk yields and a reduction in value of breeding cows. A blood test for the parasite would allow farmers to identify non-infected cattle when purchasing replacement stock, or to selectively cull infected cattle.

Using brain and spinal cord tissue from a calf suspected of carrying the parasite, the scientists grew what they believed to be N. caninum on culture medium and in immuno-deficient mice. The researchers used DNA and protein analyses to confirm that the organism they had isolated was similar but not identical to N. caninum isolated in the UK.

Now that researchers have isolated the Australian form of N. caninum, a test may be developed within a matter of months.

The Australian parasite was named Nc-Nowra, because the calf came from a farm at Nowra on the south coast of NSW. Insearch, the technology transfer arm of UTS, has filed a patent specification to protect the work.

The long term aim of the research is to develop a vaccine based on an inactivated form of the parasite.