Pre-lambing worm control
An effective drench is one of the animal health treatments that is always mentioned as part of a pre-lambing routine. Let’s have a closer look at why this can be so important and how to get the best results.
To drench or not to drench?
This really should be the first question asked and is best answered by doing a faecal egg count. This simply involves collecting 10-20 fresh samples and dropping them into Elders to get tested. This will return an eggs per gram (epg) of faeces which can be used to determine whether to drench.
At either end of the worm burden scale (none or lots) the decision is easy. But what about a low to medium worm burden? Ewes temporarily lose some of their natural immunity to worms at lambing and during lactation. This combined with often longer periods of set stocking and higher grazing pressure can lead to higher worm burdens throughout the lambing period. The drenching threshold for the Mediterranean zone of South Australia usually sits between 100 and 250epg depending on the time of lambing and rainfall.
An effective drench
When we talk about a fully effective drench, we mean one that can reduce the worm egg count by at least 98 per cent. A quick way to find out the status of your drench is to do a worm egg count up to 10 days before drenching followed by a second one between 10 and 14 days after drenching to compare the results. See the range of sheep drenches available through Elders.
Other principles for keeping your drenches effective include a combination of the following:
- rotating between effective drench groups
- using short acting drenches where possible
- using a combination of two or more actives where possible.
Article written by Emma Shattock, Livestock Production Advisor, Elders Burra (SA).
To organise a worm egg count or for more animal health information contact your local Elders branch.