Worm Control Program – Summer rainfall / tablelands and slopes

Program summary

The WormBoss worm control program for the NSW and QLD summer rainfall/tablelands and slopes region has five components that are most effective when used in combination.

Open the complete program (PDF)

A summary of the components is below (see further chapters in the PDF for details).

1. Use grazing management to create low worm‐risk paddocks

• Prepare spring lambing paddocks by preventing contamination with worm larvae in the 6 months prior to lambing:
  • March and April: spell paddocks, graze with cattle or graze with sheep for up to 21 days after the protection period (when it is killing worms) of an effective drench¹.
  • May–August: no grazing restrictions apply when maximum daytime temperatures are consistently below 18°C, if they are not then use the same strategy as for March and April.
• Prepare summer weaning paddocks by preventing contamination with worm larvae in the 3 months prior to weaning:
  • Spell paddocks, graze with cattle or graze with sheep for up to 21 days after the protection period (when it is killing worms) of an effective drench¹.

2. Breed for worm­‐resistant sheep

• Use rams with better than average worm egg count (WEC ASBVs²); choose the more negative values.
• Maintain good nutrition to enhance the sheep’s immunity to worms.

3. WormTest at recommended times

• WormTest before these routine opportunities to drench:
  • Pre-shearing.
  • Pre-lamb marking (ewes).
  • Pre-weaning (ewes).
• Weaning to shearing: WormTest at 4–6 week (summer) or 6–8 week (winter) intervals after a short-acting drench. If using a persistent drench then see ‘Effective use of long-acting drenches’.
• And at other non­‐routine times as described in the Drench Decision Guide.

4. Drench³ or use Barbervax® at recommended times

• If using Barbervax, follow the prescribed program (see ‘When to WormTest and when to drench or use Barbervax®’)
• Drench breeding ewes pre-lambing (as they temporarily lose their immunity).
• Drench lambs at weaning.
• Drench all introduced sheep with a combination of no less than 4 unrelated drench groups with at least one of these being the newest drench actives: monepantel (Zolvix®) or derquantel (with abamectin—Startect®)⁴.
• Drench individual sheep showing obvious signs of worm-related illness and WormTest the mob.
• At other times, use the Drench Decision Guide to make drenching decisions.

5. Manage drench resistance

• Conduct DrenchTests every 2–3 years. Use DrenchCheck-­Day10s between DrenchTests.
• Avoid unnecessary drenching.
• Use effective drenches and multi-active⁴ combinations where possible.
• Use short-acting treatments. Reserve long-acting products for specific purposes or high worm-risk times.
• Rotate among all effective drench groups⁴ for each mob (and each paddock where possible).
• Calibrate your drench guns, dose to the heaviest sheep and follow label instructions.
• Use of Barbervax® vaccination should slow the rate of development of drench resistance.

¹This drench must be tested and shown to be highly effective on your property

²ASBVs=Australian Sheep Breeding Values.

³Drench refers to anthelmintics regardless of route of administration.

⁴Drench groups are the chemical family to which an ‘active’ belongs. An ‘active’ is the chemical in a drench responsible for killing worms. Some drenches contain more than one active and are called ‘multi-­active’ or ‘combination’ drenches. See ‘Drench groups and actives’ at Appendices: Further information on sheep worm control for QLD/NSW summer rainfall/ tablelands and slopes.

This is an up-to-date, integrated regional worm control program for sheep in the summer rainfall/tablelands and slopes region of New South Wales and southern Queensland. It builds upon earlier programs (including from the state departments of primary industries: NSW DPI and Qld DAFF) and accumulated knowledge, as well as new information from the Integrated Parasite Management in Sheep project, funded by Australian Wool Innovation and the Sheep CRC.

The program aims to improve the profitability and welfare of your sheep through:

• fewer deaths and illness from worms
• fewer drenches, particularly long-acting drenches
• improved productivity
• prolonged life of drenches