Pre-lambing ewes need the best protection.

Pre-lambing ewes need the best protection

PRE-LAMBING ewes need the best protection against worms at lambing to safeguard their health, reduce pasture contamination and to optimise the productivity of their lambs.

Elanco Technical Services Veterinarian, Dr Nicholas Rolls, says effective pre-lambing worm control provides a number of direct benefits for both ewes and lambs.

“Lambing ewes are more susceptible to worm burdens, and significant pasture contamination can occur if these burdens are not controlled,” he says.

“Effective worm control in ewes before lambing not only improves the productivity and welfare of ewes and lambs(1,2) but reduces pasture contamination and subsequent exposure of lambs to infection.

“Research has shown the preparation of clean lambing paddocks can increase lamb growth rates and survival(3,4) and reduce the frequency of drenching required after lambing.”(1)

Dr Rolls says the preparation of low-risk pastures before lambing is crucial in helping to avoid high worm pressure.

“Reaching for the drench gun at marking is often too late to reduce the impact of worms upon production and profitability,” he says.

“Depending on regional conditions, spelling selected paddocks for two to five months before lambing will help minimise contamination of pasture with worm larvae.

“As stocking pressure doesn’t always allow for spelling, grazing with cattle is an alternative option or even grazing with sheep that have recently been treated with a ‘fully effective’ drench.”

Monitoring worm burdens in ewes prior to lambing is crucial to allow appropriate decisions to be made.

“Ewes should be drenched within three or four weeks of lambing once worm egg count thresholds for your region are exceeded,” Dr Rolls says.

“These range from as low as 75 eggs per gram (epg) in high winter rainfall regions in south-eastern Australia to 200 epg in drier regions, such as Western Australia.

“If drenching is required, use a short-acting drench that is known to be effective on your property.”

Dr Rolls says Zolvix™ Plus (25 g/L monepantel and 2 g/L abamectin) is ideal for use as a pre-lambing drench.

Zolvix Plus is a unique combination drench that contains monepantel, the only member of the amino-acetonitrile derivative (AAD) or ‘orange’ class of anthelmintics.(5)

Its unique mode of action provides more than 99.9% efficacy against a broad spectrum of internal parasites, including single, double and triple resistant strains.(6,7)

“Zolvix Plus is a great choice if the resistance status of other drench classes is unknown or if resistance to other actives is already severe,” Dr Rolls says.

“There is widespread single, double and triple resistance to all older active ingredients, including moxidectin.”(8)

“Any reduction in drench efficacy has a direct impact on the health and productivity of your sheep throughout the year.

“Even mild or moderate levels of drench resistance can reduce potential income by 2 to 10%.(9)

“It can be reasonably estimated that a 15% reduction in drench efficacy can cost about $3 per ewe in lost production, while a 35% reduction in drench efficacy costs more than $15 per ewe.(10)

“Ewes are the foundation of your lamb and wool enterprise and deserve the very best protection against internal parasites.

“Paying a few cents per head more for a drench that is known to be ‘fully effective’ is a sound investment to safeguard the productivity and profitability of your flock.”

Dr Rolls says Zolvix (25 g/L monepantel) is ideal for use in combination with long-acting anthelmintic capsules or injections.

“Long-acting anthelmintics are a popular pre-lambing treatment, particularly if clean paddocks cannot be prepared in time for lambing,” Dr Rolls says.

“However, widespread resistance to mectin drenches, including moxidectin, and white drenches can significantly impact the efficacy of these treatments.

“The administration of an effective short-acting ‘primer’ drench from a different chemical class at the same time as the long-acting anthelmintic will reduce any existing worm burden present at the beginning of the treatment period.

“Likewise, the administration of an effective ‘exit’ drench towards the end of the protection period of the long-acting treatment will remove any resistant worms that survived either the initial treatment or during the ‘tail’ period as the activity of the long-acting drench declined.

“Importantly, it stops ongoing pasture contamination with worm eggs that will give rise to an increasingly resistant population.”

Again, WEC monitoring is recommended throughout the pay-out period of the long-acting treatment to check for effectiveness.

An early exit drench is recommended if WEC exceeds 100 epg at any time during the claimed protection period of the long-acting product.

Always read and follow the label directions. Good agricultural practice is essential for optimal worm control. Resistance may develop to any chemical.  Ask your local veterinary practitioner or animal health advisor for recommended parasite management practices for your area to reduce development of resistance.  It is advisable that a resistance test be conducted before any parasite treatment is used.

Zolvix Plus contains 25 g/L monepantel and 2 g/L abamectin. Zolvix contains 25 g/L monepantel. Zolvix™, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. ©2021 Elanco or its affiliates. PM-AU-21-0126 EAH21104.

References: 1. Bailey, J.N. et al. (2009). Comparison of strategies to provide lambing paddocks of low gastro-intestinal nematode infectivity in a summer rainfall region of Australia. Vet. Parasitol. 161:218-231. 2. Kahn, L.P. et al. (1999). Enhancing immunity to nematode parasites in pregnant and lactating sheep through nutrition and genetic selection. In: Animal Science, University of New England, Armidale. 3. Kelly, G.A. et al. (2010). Integrated parasite management for sheep reduces the effects of gastrointestinal nematodes on the Northern Tablelands of New South Wales. Anim. Prod. Sci. 50:1043-1052. 4. Cobon, D.H. and O’Sullivan, B.M. (1992). Effect of Haemonchus contortus on productivity of ewes, lambs and weaners in a semi-arid environment. Journal of Agricultural Science 118:245-248. 5. Refer to registered label. 6. Hosking, B. et al. (2010) A pooled analysis of the efficacy of monepantel, an amino-acetonitrile derivative against gastrointestinal nematodes of sheep. Parasitol Res 106:529–532. 7. Baker, K.E. et al. (2012) Efficacy of monepantel and anthelmintic combinations against multiple-resistant Haemonchus contortus in sheep, including characterisation of the nematode isolate. Vet Para 186(3–4):513–517. 8. Playford, M.C. et al. (2014). Prevalence and severity of anthelmintic resistance in ovine gastrointestinal nematodes in Australia (2009-2012). Aust Vet J 92(12):464–471. 9. Besier, R.B., et al. (1996). Drench resistance – a large economic cost. J. Agric. West. Aust. 37:60–63. 10. www.dpi.nsw.gov.au/agriculture/budgets/livestock