MSD Animal Health has introduced FLEXOLT®, the world’s first oral lice treatment for sheep in New Zealand
Administered orally, like a drench, it works from the inside out so farmers can treat lice in their flocks at any time of the year, with any length of wool and in any weather.
Depending on the level of infestation, lice are estimated to cost New Zealand’s fine wool sheep farmers between $7000 and $8000 per year per 1000 ewes in lost wool clip, because of a reduction in fleece weight, cotted fleece, and discolouration.
MSD Animal Health veterinary technical advisor for the Lower North Island, Hamish Pike says FLEXOLT’s rapid absorption means it starts working within one day of sheep being treated. While it’s eliminated from the bloodstream quickly, it’s retained in the wool fibre, which means that the chemical remains in the wool long enough to allow the eggs to hatch and eliminate the emerging nymphs.
Adrian Lawson and partner Kirsty Watson, who manage a 163-hectare property at Waituna, east of Invercargill, have been using various methods to control lice. Romney sheep have been the backbone of their operation, in which they run 1550 ewes, 370 hoggets, and a small herd of cattle.
Adrian, a former New Zealand Romney Farmer of the Year, says, as a new form of treatment, he thought FLEXOLT was helpful in that it could be used in sheep of any wool length and because it is unaffected by rain. Adrian’s business model relies on breeding as many fast-growing lambs as possible to heavy weights, so he aims to have lambs gaining 250g to 300g a day.
“Lambs don’t do as well if they’re scratching at themselves. It’s great to have a new treatment option, as unfortunately lice treatments are becoming like worm treatments — there are less of them that are effective.”
Adrian’s property hosted an independent trial of FLEXOLT in 2021 prior to its commercial release. Thirty lousy sheep were tagged to monitor for lice counts from the trial mob, which numbered approximately 300 sheep and Adrian was surprised to observe that sheep stopped rubbing within a day of treatment indicating its immediate impact. Lice counts were undertaken at one, two, three, six, 14, and 21 weeks post-treatment, with promising results showing FLEXOLT was 99.96% effective out to 152 days.
“FLEXOLT is helpful if a farmer finds a lice problem in the lead up to lambing, as its administration method minimises stress on the ewes and ensures lice are controlled prior to lambing,” says Adrian.
Hamish says treating lice with FLEXOLT is simple and effective because it’s administered orally, and common application errors associated with traditional lice treatments are avoided.
“If farmers treat 100% of their flock with FLEXOLT and follow strict biosecurity measures like quarantining any new sheep coming onto their property and ensuring boundary fences are secure, it’s feasible that sheep would not need to be treated again on that farm for some time,” says Hamish.
Pauline Calvert, business unit lead at MSD New Zealand, says the launch of FLEXOLT in New Zealand shows MSD’s commitment to innovation for New Zealand’s sheep industry.
“The cost of lice to New Zealand sheep farmers is significant in terms of lost revenue, animal health, and labour costs. MSD is proud to be providing a product that creates efficiencies for both lice management and on-farm,” says Pauline.
While FLEXOLT can be used year-round, treating flocks for lice at least four weeks before lambing is likely to be one of the best times, as it prevents lice from transferring to newborn lambs.
FLEXOLT is available now through vet clinics nationwide.
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