Capacity building and validation of Integrated Parasite Management in prime lambs in WA

Summary

​The project aimed to quantify the potential loss of growth and value in prime lambs in Western Australia due to worm infections, and to develop integrated parasite management based prime-lamb specific control recommendations. The focus of this study was on the worm species which reduce growth rates in prime lambs (non-Haemonchus sp.).

Observations were conducted over 3 years on 14 properties throughout South-West Western Australia, with worm egg counts and lamb weights measured at intervals from lamb marking for the next 105 days. The results suggest that best-practice worm control over the critical period for prime lamb growth should include:

• ensuring that growth rates are 240 grams per head per day or greater in the first 14 weeks after the start of lambing;
• conducting worm egg counts about 10 weeks after the start of lambing;
• weaning and giving an effective (>98%) drench shortly afterwards if the count is over 250 eggs per gram; and
• drench onto lower worm burden paddock. All of these practices would be cost-effective given the significant economic value to be gained when prime lambs are slaughtered around 28 weeks after the start of lambing and they are also relatively easy to implement.