L.PDS.2215 - PDS: Optimising liver fluke management in cattle

Summary

Liver fluke infection remains a widespread challenge for cattle enterprises in the high-rainfall regions of south-eastern Australia. This project aimed to optimise producers’ management of liver fluke through investigating the prevalence of liver fluke, evaluating drench resistance, and determining the impact of drench timing on the growth of young cattle. Faecal egg counts, fluke egg count reduction trials and treatment comparison trials were conducted across beef properties in northeast Victoria and southeast New South Wales. Liver fluke was commonly detected, although several farms with suitable environments showed no infection, highlighting the need for evidence-based monitoring rather than routine drenching. Resistance to triclabendazole was confirmed on all seven core producer farms; however, no measurable production loss from resistance was identified, likely due to low burdens, compromised but sufficient efficacy, or short monitoring periods. Pre-winter drench timing affected winter growth rates, with poorly timed treatments reducing growth of weaners by 8–15%. Economic analysis showed no direct cost from resistance but demonstrated substantial impacts from incorrect drench timing, influencing gross margins and production costs. Extension activities improved producer knowledge, skills, and confidence, leading to practice change. The project underscores the importance of strategic drenching, routine monitoring, and further research into productivity impacts and improved diagnostic protocols.

Objectives

By September 2025, in northeast Victoria and southeast New South Wales: 

1.    Estimate the prevalence of liver fluke in beef cattle by conducting fluke egg counts on faeces collected from cattle on three to five core and 30 observer producer farms 

2.    Determine the prevalence of liver fluke drench resistance to triclabendazole by fluke faecal egg counts on core producer properties and/or on observer producer properties where fluke has been identified through the prevalence survey 

3.    Using focus groups with core and observer producers, record their current protocol for controlling liver fluke in cattle, including use of drench, monitoring and environmental control (eg. fencing off ‘flukey’ areas) 

4.    Set up three different treatment/monitoring protocols for the control of liver fluke in cattle on three to five core farms with known liver fluke, and demonstrate the effects on: 

a.    Weight gain in young stock - show any increase in growth rate in the 6-month period following treatment 
b.    Fluke faecal egg counts (used to monitor infection), and 
c.    Livestock Data Link for abattoir feedback (used to monitor infection). 

5.    100% of core producers and 50% of observer producers will have increased their knowledge and confidence in managing liver fluke.

Key findings

•    Liver fluke was prevalent on many farms, but not all properties with ideal conditions had infections, highlighting the need for monitoring rather than routine drenching. 
•    Triclabendazole resistance was confirmed on all core farms, though no production impact was observed—likely due to low fluke burdens and short monitoring periods. 
•    Strategic pre-winter drenching improved weaner growth by 6.8–13 kg, while mistimed or missed drenches reduced growth by up to 11 kg and lowered gross margins. 
•    Optimal drench timing increased productivity by 32 kg/ha and improved gross margin by $10/DSE, while early or missed treatments raised costs and reduced returns. 
•    Producer knowledge, skills, and confidence improved significantly, with 85% of core producers and 52% of observers reporting increased understanding and practice change.

Benefits to industry

•    Improved monitoring for fluke infections through fluke egg counts or copro-antigen ELISA is a tool that more producers in the red meat industry need to adopt to enable informed decisions around the timing of a drench and if a drench is needed or not, rather than routine drenching. 
•    Confirmation of resistance on producer’s farms, despite no demonstrated production impacts, is still important to enable producers to make informed decisions about which drench product to use, prolonging the effectiveness of an important drench to the red meat industry. 
•    Optimising the time of the pre-winter drench will improve the kilograms of beef produced per hectare. 
•    Liver fluke is having an impact on production if left untreated and could reduce overall profitability of red meat enterprises

MLA action

MLA continues to deliver the Producer Demonstration Site (PDS) program, supporting livestock producers working in peer-to-peer groups to pursue new skills, knowledge and management practices applicable to their own commercial livestock production systems.

Future research

Based on the results of this project, there were three areas for future research. These were: 
•    What is the impact of drench resistance 
•    having on productivity? 
•    What impact is fluke having on productivity, especially on farms which have low fluke egg counts?
•    Improved monitoring protocols to inform drenching decision.