Worm Control Options This Autumn
/After a rain event it can take a couple of weeks for the sugars to re-establish in grass and it is also an opportunity for parasite larvae to re-emerge and have a chance to complete their life-cycle.
With a synchronised hatch of parasites and rapid development to infective stage, worm control in lambs/hoggets, 2 tooths and lighter mixed age ewes is beneficial. For the most part an effective combination oral drench is sufficient. For lambs drench interval needs to be every 28 days. DON'T LET YOUR DRENCH INTERVAL SNEAK OUT TO 5 WEEKS+, unless a FEC drench check indicates you can. If the worm burden has ramped up very quickly and pastures are heavily contaminated then persistent acting drenches can get your lambs out of a parasite rut. Exodus LA or Cydectin LA, are options but they will need an exit drench 70-90 days later. A novel drench is ideal (see below). For fine wool lamb traders long acting injectable drench is very appealing to keep them going well through the autumn.
Using a novel active drench on lambs/hoggets at some stage through March - May is recommended to clean out any resistant parasites that have accumulated. Zolvix plus and Startect are the two options. For farms where certain drench resistance has been diagnosed then targeted use of novels on ewes at pre-tup is advised (e.g. Startect to 2 tooths, light ewes).
In these conditions using adult cattle behind lambs or ewes behind calves is a very good way of maintaining lower levels of parasite burdens through a "wormy autumn".