Optimising liver fluke management in cattle
| Project start date: | 30 November 2021 |
| Project end date: | 30 September 2025 |
| Project status: | In progress |
| Livestock species: | Grass-fed Cattle |
| Relevant regions: | NSW, Victoria, Tasmania, Temperate, Temperate sub-humid |
| Site location: | Victoria and southeast NSW |
Summary
Liver fluke infection is widespread in cattle and sheep across high rainfall areas (>600 mm) of south-eastern Australia and other irrigated areas. Due to the lifecycle of liver fluke and its reliance on a snail to complete the lifecycle, eradication is impossible. Therefore, control and prevention of disease through grazing management and strategic flukicide use are important. However, the reliance on the anthelmintic triclabendazole, and the increasing resistance to this chemical is of concern.
This producer demonstration site (PDS) aims to demonstrate the use pf diagnostic tools (fluke egg counts and feedback data from Livestock Data Link) to improve the management of liver fluke in cattle to increase in production and economic returns.
Objectives
By September 2025, in northeast Victoria and southeast New South Wales:
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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
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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
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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)
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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:
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Weight gain in young stock - show any increase in growth rate in the 6-month period following treatment
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Fluke faecal egg counts (used to monitor infection), and
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Livestock Data Link for abattoir feedback (used to monitor infection).
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100% of core producers and 50% of observer producers will have increased their knowledge and confidence in managing liver fluke
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Seventy-five percent of core producers and 50 percent of the observer producers will intend to adopt/or change their current management with revised treatment, monitoring and control protocols in their area
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Conduct a workshop with the core and observer producers to discuss the results of the prevalence survey and drench resistance results.
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Conduct an end of PDS field day to showcase the treatment, monitoring and control protocol demonstration results to 50 producers in north-east Victoria and south-east NSW.
Progress
The Producer Demonstration Site Project “Optimising Liver Fluke Management in Cattle” commenced in May 2022 in south eastern NSW and north eastern Victoria. It is coordinated by Leah Tyrell from the Mackinnon Project, University of Melbourne.
Seven fluke egg count reduction trials were set up in 2023. Drench resistance to oral Triclabendazole was identified on all seven farms with the percent reduction ranging from 0 to 86%. There were difficulties in interpreting the significance of the reduction due to low egg counts, however what was revealing was the fact that there were still eggs present after drenching cattle with oral Triclabendazole. Also included in the trial was Nitroxynil/clorsulon injection.
Results indicated that there was no evidence of resistance with reductions of 100%. Animals in each group were weighed at the start and end of the reduction trial to determine if drench resistance had any impact on weight gain over a period of 28 days. There was no difference between the weight of the control group (untreated) and the groups treated with Triclabendazole, despite resistance being present. The group treated with Nitroxynil/clorsulon tended to have a higher weight gain over this period compared to both the control and Triclabendazole groups, but it wasn’t significant.
The treatment comparison trials were set up at weaning in April/May on three demonstration sites. Of the results from the three farms, only one can be used due to the other two farms having significant resistance present to oral triclabendazole, the drench used to treat the cattle in either May or August. Due to triclabendazole being ineffective, no direct comparison of time of treatment could be made on these two farms.
On the farm which did not have significant resistance present, the average daily weight gain over the duration of the trial was the same for each group (Group 1 – producer’s normal protocol which was to drench with nitroxynil/clorsulon in May, Group 2 – oral triclabendazole in May and Group 3 – oral Triclabendazole in August). However, following each treatment, the average daily gain of the group that was treated, either Group 2 or 3, was from 100g to 330g greater than the other 2 groups, respectively. The fact that there was a difference in weight gain following each treatment, but none at the conclusion of the trial indicates that there was some compensatory growth occurring in these weaners.
Activities planned for 2024 include; set up Year 2 of the treatment comparison trial on the same 3 farms but to use an effective drench product, and to undertake four more drench resistance trials.
