Wormwise Advice: Managing Resistant Worms After Drench Testing
Ginny Dodunski, Wormwise's programme manager, Beef+Lamb New Zealand, outlines what to do when faecal egg counts indicate that worms are surviving your drench.
Boehringer Ingelheim, the distributor of Bionic Plus, has announced the adult sheep product is unlikely to be available for lambing in 2023.
“Farmers need to begin planning now,” says Dr Ginny Dodunski, sheep veterinarian and manager of the Wormwise programme.
“There are plenty of farmers around New Zealand who get great ewe performance and excellent lamb weaning weights without the use of any pre-lamb worm treatment for ewes – but the key to this are ewe body condition and feed planning. Getting this right for lambing starts the day you wean,” Dodunski says.
Last year, issues with the Bionic Plus Hogget capsule saw the product recalled and an extended meat withholding period applied to sheep already treated with the capsules. While investigations continue, it appears the capsules were not releasing product at the correct rate.
Boehringer has advised vets that out of an abundance of caution, it is ‘highly unlikely’ that either capsule will be available in 2023.
Dodunski says that while other long-acting products are available, the unavailability of Bionic Plus could be an opportunity for farmers to reset their breeding flock management.
“We know from previous trial work that the factor that comes closest to explaining why some farms see big responses to capsules is feed on offer at lambing.
“This is something that every farmer has some control over. It’s a mix of lambing date, stocking rate, autumn and winter sales policies, grazing management and fertility,” Dodunski says.
“However, you can’t wake up on the 10th July and decide to increase the amount of grass on offer at lambing – this process starts now and relies on hitting appropriate pre-winter feed targets and then managing that feed through to have good covers to set stock multiple ewes onto.
“The farmers I see who do a really good job of this do a lot of juggling in the second half of the winter to aggressively aim for those targets while still feeding their multiples well in late pregnancy.”
She says identifying ewes that are under body condition score 3 to 3.5 at weaning and offering them extra feed over summer marks the beginning of this process.
Farmers who would like training in any aspect of feed planning, body condition management and sustainable drench use are encouraged to contact their local B+LNZ extension manager for workshops in their area.
