Why Worm Control?
Burdens of cattle worms can lead to reduced liveweight in and associated with worm disease like diarrhoea and illthrift. A worm control programme will benefit the animals health as well as adding to the profitability at sale time.
There are four drench groups:
- Combination drenches (for example, Eclipse® or Trifecta®) should be fully effective against all worms in cattle herds including those where drench resistance has developed. This drench group contains an ML as well as one or two other drench components. It is the preferred drench when treating yearling cattle at weaning to reduce the chance of survival of any resistant cattle worms.
- Macrocyclic lactones or single ML drenches e.g. doramectin, abamectin (Avomec®), ivermectin (Ivomec®, Ivomec® Eprinex®, Bomectin®), and moxidectin (Cydectin®, Cydectin® Long Acting) – injectable and pour-on formulations. This group will also control sucking lice and ticks. The single ML group of drenches can be used in cattle herds where the brown stomach worm is not suspected or known to have resistance to this drench group. The ML drenches kill the larval stages of the brown stomach worm which is very important to minimise future burdens of this parasite during winter. Residues of some of the ML drenches in cattle dung may have a harmful effect on dung beetles.
- Bezimidazoles or white drenches (for example, WSD Fenbendazole Oral®, 4Farmers Fenbendazole Oral®, Fencare®, Panacur®, Systamex®) – oral drench and rumen injection formulations. Brown stomach worm resistance to white drenches has been demonstrated on 50% of tested cattle herds in WA.
- Levamisole or clear drenches (for example, Levamisole Gold LV®, Coopers Nilverm oral or pour on®, WSD levamisole®) – oral drench, injectable and pour-on formulations. Brown stomach worm resistance to clear drenches was detected on 50% of tested herds in WA.
Routine treatment of beef calves is rareley necessary prior to weaning.
Weaners / Yearlings
Drench at weaning with a combination (preferred) or a single ML drench (check your worm drench resistance status). If there has been a history of possible worm problems during winter on the property then an additional preventative treatment in autumn with a combination or single ML drench may be useful.
Two Year Olds / First Calf Heifers
Young adults are potentially more susceptible to the effects of worms during winter compared with mature adult cows. A preventative autumn drench to young adults may be warranted if you have a history of worm problems in your herd.
Mature Adult Cows
Mature adult cows have a stronger immune system which leads to only a minor worm burden. Therefore routine worming is not usually necessary and treatment can be limited to when signs of worm disease are evident.
Bulls are more at risk from the effects of worms compared to mature adult cows and a preventative autumn drench before joining is a good precautionary measure.