Maxine Lyndall-Murphy, WormBuster Lab, Brisbane.
Despite the vagaries of the season, hot, dry and windy conditions following on from a few days of severe cold, wormtests are showing that sheep are still carrying very high worm egg counts averaging 2000-4000epg in the Balonne, Booringa, Waggamba and Stanthorpe shires. These have been predominantly Haemonchus (Barber’s Pole worms) but with background levels of nodule, mostly in older sheep. If you slaughter any sheep on property always open up the abomasum and large intestine. You will easily seen worms if they are there. Drench products containing a BZ or an ML active ingredient will control nodule.
The lambing ewes are the mobs most affected by worms, even though most were drenched pre-lambing. Little rain has fallen since June, resulting in a shortfall of good nutrition for this needy class of stock, especially the twin lambers, leaving them susceptible to repeated worm infections. Most producers are reporting long, dry grass with an understory of short green pick. If short green grass is available then the conditions that promoted this growth are the same as those required by worm larvae to survive on pasture. It would be a good guess that re-infection is taking place!
If your lamb worm egg counts were zero in a recent worm test despite high counts in the ewes, retest the lambs in 2-4 weeks. It takes 21 days for ingested worm larvae to mature into adults and produce eggs in dung. Definitely WormTest about two weeks before lamb marking – both ewes and lambs (use 10 bottles from the WormTest kit for the ewes and five bottles for the lambs and number appropriately). If you need to drench lambs, read the labels to be sure the product is suitable, especially for lambs less than six weeks old.