Study to investigate chlamydia effect on lamb losses

chlymidiaA new AWI-sponsored project is investigating the role that Chlamydia has on sheep health and lamb losses in Australian flocks, and aims to develop a simple cost-effective test for the disease.

Dr Tom Clune, who is undertaking a PhD research project at Murdoch University, will undertake the 12-month project through an AWI-sponsored Science and Innovation Award for Young People in Agriculture.

Growing up on a sheep farm near Geraldton in Western Australia, Tom developed an appreciation for the importance of animal health and welfare from a young age. It led to a career as a veterinarian, and the start of a PhD in infectious diseases recognised for causing reproductive losses in sheep.

“This new project complements my current PhD project and will improve the sheep industry’s understanding of how Chlamydiainfections might contribute to lamb losses,” Tom said.

“Reducing lamb wastage is a priority for the sheep industry, as it will improve farm productivity and animal welfare, and address risks to community support for wool production.

“Lamb loss between mid-pregnancy and weaning is associated with a $1 billion annual productivity loss for Australian agriculture, yet the underlying causes of pregnancy losses and stillbirths remain poorly understood. Preliminary findings from my PhD project have indicated that Chlamydia is a disease that might have been overlooked.

“In conducting my PhD fieldwork in 2018-19 on ten WA farms, I found Chlamydia infections were present in more than half of abortion or stillborn cases, suggesting Chlamydia might cause significant wastage under some circumstances, although the wider economic impacts of the disease are not known.”

“In conducting my PhD fieldwork in 2018-19 on ten WA farms, I found Chlamydia infections were present in more than half of abortion or stillborn cases.”
– Dr Tom Clune

The Chlamydia bacteria that causes disease in sheep is different to the bacteria that causes disease in humans. Chlamydia pecorum is widespread in Australian sheep, and healthy sheep shed the bacteria in faeces.

The new study will, for the first time, characterise abortigenic strains of Chlamydia using genome sequencing tools. The project will utilise the tissue samples already obtained as part of Tom’s PhD, reducing costs and risks involved with fieldwork, and with no need for additional animal use.

“Through this project I aim to discover the Chlamydia bacteria’s distribution, transmission and factors that determine how that leads to abortions or stillbirths or the birth of weak lambs,” Tom said.

“This new knowledge will underpin recommendations for sheep producers to manage the disease, with production and welfare implications.”

As part of the project, Tom also plans to develop a quick, cheap and portable tool for diagnosing Chlamydia in sheep. It will be based upon a test already developed for detecting infections in wildlife and horses.

“It takes about 45 minutes to run, so vets can either take it out onto the farm or take samples and take it back to the clinic,” he said.

“There are other diagnostic tests available, but this would be much cheaper and have a quicker turnaround so vets can work with the farmer to make timely decisions about controlling an outbreak.”

This project will involve collaboration between Murdoch University, the Department Primary Industries and Regional Development WA and the University of the Sunshine Coast.

The Science and Innovation Awards for Young People in Agriculture are coordinated by ABARES and are open to young people aged 18-35 years working or studying in rural industries. The annual awards aim to encourage the uptake of science, innovation and technology in rural industries.

Thomas was presented with his award in March and he aims to complete the research plus the development of the diagnostic tool by June next year.

-AWI