Dairy Weaner worm management: It’s not all about drenching!

With consistent rainfall and warm temperatures around Taranaki, we have been fielding a lot of queries around facial eczema (FE). These weather conditions are not only good for FE they are also ideal conditions for worm survival on pasture. It is important that every farm has some form of worm management plan in place to deal with this. The goal of any worm management plan is to maintain or enhance profitability by:

  • Minimising contamination of pasture with infective worm larvae.
  • Minimising uptake of infective larvae by susceptible stock.
  • Monitoring the effectiveness of the worm management strategies.

Farmer knowledge, pasture management, stock management, drenching, and the use of genetics are all tools that should be incorporated into a worm management plan.

Drenching is just one part of most worm management plans. The aim of any good drenching program is to limit the effects of the worm on the individual animal and at the same time reduce the subsequent larval challenge on the pasture in the next round. Most farmers would follow a preventative drench regime where calves are drenched at regular intervals from weaning until winter. The timing of the last drench is generally determined by environmental conditions.

Exciting work is underway around the country looking at Targeted Selected Treatments (TST). The goal of TST is to improve profitability (by drenching fewer animals) and prolong the longevity of the drenches we have available to us. It works by identifying those animals that require drenching.  A TST programme requires strict monthly weighing to monitor live weight gains. Animals not achieving the required weight gains get drenched and those growing at target are left un-drenched. If you are interested in knowing more about TST, contact your local animal health advisor or contact a Wormwise representative.

As with any drenching programme, drench resistance should always be at the forefront of your mind. Some key points to consider that may help delay resistance on your farm: Avoid drenching more frequently than every 28 days, where possible drench and return to the same paddock they came from (unless you are practicing refugia and leaving some undrenched or you are using TST), use effective combination drenches (faecal egg counts should be used to check the effectiveness of a drench), drench to the correct dose using correct technique with a regularly calibrated gun.