14/11/2025
Preweaning drenching...
Preweaning drenches have long been touted as a necessity in Southland, particularly due to concerns with Nematodirus, but with weaning getting earlier and earlier is there still the need for this drench? Much of the focus of the importance for preweaning drenches came about as lambs were being weaned in January (as was common 20 years ago). Now most lambs are weaned in December, with many in early December or even as early as late November. Is the preweaning drench, often done a month before weaning, still important? Arguably not.
The need for a preweaning drench (and when to do so) should be a seasonal decision. Factors such as predicted weaning date, pasture covers, ewe condition, FECs from lambs and what lambs look like should all be considered. If a preweaning drench is deemed necessary, aiming for 4 weeks before weaning was always a practical guideline, but maybe 2 weeks is more appropriate in some circumstances. This ensures lambs should still be outside WHPs and avoids the need for a drench at weaning, thus easing the weaning workload. I appreciate this may mean another yarding for drenching pre-xmas but this may still work?
Drenching to a calendar or prescribed set of ideas or 'what we always do' should be a thing of the past. Use your stock sense, pasture knowledge and tools available to make an informed decision and help avoid wasting your money on unnecessary drenches.
Note: I appreciate that this spring may be a year when an early preweaning drench is necessary - for many Southland sheep farmers low pasture covers and poor ewe condition may make this worthwhile. These factors may also mean early weaning is a consideration for less competition and improved lamb growth - lots to ponder...
Wormwise DAGI Beef + Lamb New Zealand Southern South Island
