Conference Agenda

Gastrointestinal nematodes impose economic burdens on the sheep industry, impacting on animal welfare and management costs. Species surveillance is essential, yet larval culture is inefficient for large‑scale monitoring. Nemabiome deep-amplicon sequencing allows for sensitive detection of nematode species directly from eggs without having to hatch eggs for 10-14 days like larval culture.

This study compared larval culture with nemabiome sequencing to speciate worms from bulk faecal samples from 27 farms. Spearman’s correlations showed significant positive correlations for Haemonchus contortus (r_s=0.56, p<0.01), and Teladorsagia circumcincta (r_s=0.58, p <0.01) and a moderate positive correlation for Trichostrongylus spp (r_s=0.34, p=0.07). Positive correlations between the two techniques provides some confidence that nemabiome sequencing is useful for large-scale surveillance of nematode species across Victoria, which is being completed on saleyard samples collected four times a year for a two-year period.

Initial findings on 100 samples show that Victoria’s most abundant species are Teladorsagia circumcincta (92%), Trichostrongylus vitrinus (78%) and Haemonchus contortus (54%). Given the high prevalence and pathogenicity of T. vitrinus compared to other Trichostrongylus species more research should focus on understanding this worm to enhance management strategies. Less common species included Trichostrongylus colubriformis, Chabertia ovina, Trichostrongylus axei, Oesophagostomum venulosum, Nematodirus spathiger and Trichurus ovis.