To carry out the proposed study, 45 Merino wethers will be randomly sampled per property (ten properties in total). During initial sample collection, each animal will be weighed and randomly allocated to one of three treatment groups (placebo – negative control, TBZ, or Closantel; N = 15 per group). Treatments will be orally administered at the recommended dosage according to manufacturer’s recommendations. Faecal samples will be collected and tested at The University of Sydney using both a traditional sedimentation/faecal egg count (FEC) and coprological ELISA to inform current farm -level prevalence within the NSW Southern Tablelands. Remaining faecal samples from each property will be pooled per treatment group for faecal flotation/FEC and Nemabiome next generation sequencing (NGS) to explore the diversity and abundance of nematode species on each property and their potential impacts on animal morbidity/study outcomes.
After 21 days a second collection of faecal samples will be conducted on the original animal cohorts. Faecal samples will again be tested with traditional sedimentation/FEC and coprological ELISA. A routine faecal egg count reduction test (FECRT) will be carried out to determine changes in egg levels. Coproantigen levels relative to the untreated controls will be used to further verify the presence/absence of drug resistant F. hepatica. During this subsequent sample collection, surveys will be distributed to farmers on all ten properties to understand producer knowledge, attitudes and livestock management practices concerning F. hepatica infection. Data analysis will include the generation of maps (ArcGIS Pro) on the prevalence of F. hepatica across the ten properties, and the presence/absence of drug resistant F. hepatica. Effective control options of F. hepatica will be provided through diagnostic reports and strategic guidelines to all ten properties.
1. Data collection:
– Initial collection: 45 wethers will be randomly sampled per property (ten properties in total)
– Faecal samples (minimum 10g/head) will be collected from each animal to record current farm- level prevalence within these flocks situated in the region of the NSW Southern Tablelands
– Second collection: After 21 days, a second round of faecal samples will be collected from original animal cohorts
2. Treatment groups
During initial sample collection, each animal will be weighed and randomly allocated to one of three treatment groups (placebo – negative control, TBZ or Closantel). Each treatment group will consist of 15 wethers.
5. Data analysis:
– Initial faecal samples will be tested using traditional sedimentation/FEC and coprological ELISA to determine baseline F. hepatica burden and prevalence
– Second collection of faecal samples will undergo the same method described above, and changes in egg levels will be determined by a routine FECRT. Changes in coproantigen levels relative to the untreated controls will be used to further verify presence/absence of drug resistant F. hepatica.
– At both time points, remaining faecal samples from each property will be pooled per treatment group for a faecal flotation/FEC combined with NGS to determine the diversity and abundance of nematode species on each property.
4. Farmer survey:
– During the second sample collection, farmers will be surveyed to gauge producer knowledge, attitudes and livestock management practices surrounding F. hepatica infection
5. Data analysis:
– FECRT and changes in coprological antigen levels will be analysed in GraphPad Prism to confirm or deny suspected drug resistance against two anthelmintics (TBZ and Closantel)
– Maps will be generated in ArcGIS Pro to inform the geographic distribution and prevalence of F. heaptica across the 10 properties
– NGS data will be analysed using standard bioinformatic Nemabiome pipelines in R to inform the abundance and diversity of concurrent nematode infections
– Diagnostic reports and strategic guidelines on effective F. hepatica control options will be provided for each property.