“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 is ewe body condition and feed planning.”
While there were other long-acting products available, the unavailability of Bionic Plus could be an opportunity for farmers to look at a “re-set” of their breeding flock management, Dodunski said.
The feed on offer at lambing was a factor that came closest to explaining why some farmers saw big responses to the capsules, a previous trial run by Dodunski found.
“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.
“However, you can’t wake up on July 10 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 on to.
“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 said.
The cost-benefit of treating skinny ewes with long-acting products was typically bigger than that of treating well-conditioned ewes, so better outcomes could be achieved if the number of light ewes in the flock could be minimised at lambing, Dodunski said.
Identifying ewes under the body condition score of 3 to 3.5 at weaning and offering them extra feed over summer was the beginning of the process.
