Victoria worms, flies and lice update - September 2016

Hamilton: Andrew Whale, Livestock Logic (a.whale@livestocklogic.com.au)

Livestock Logic Key Recommendations

• Take preventative measures now to control flystrike
• Monitor weaners for worms every 3 weeks
• Monitor adult stock for worms every 4–5 weeks
• Warning: non-clinical (moderate) worm burdens will stymie weight gains

Enjoy this relatively low worm risk period, but keep your drench guns oiled up because worms will bounce back, particularly if we have a bumper spring and go into next summer with a much greater bulk of feed.

Livestock Logic: comparison of 2016 winter worm levels to other years

• The percentage of mobs tested in July and August (2016) that had a worm egg count (WEC) above 200 epg, was well below levels typically seen for winter, particularly for the mature age ewe mobs in July 2016 (see table).
• A dry spring last year, and minimal dry carry-over feed meant a good kill of worm larvae on pasture in summer. The year started with relatively low pasture contamination levels, and continued low as good pasture growth later in winter further diluted the worm pickups.
• Even though WEC results, on average, have been low, 5% of weaner WECs have been over 500 epg.

Flystrike issues are expected to develop in the south west within the next 3–4 weeks as soil temperatures increase causing the fly life cycle to commence. Areas north of Hamilton will have fly pressure in the next 1–2 weeks, particularly if sheep stay susceptible with continued spring rainfall.