From 2010 to 2014, the King’s sheep and beef farms were part of a trial on drench resistance, only to discover they were unknowingly breeding resistance. Today, they have a strategic drench programme in place and, using both a triple active drench and Zolvix™ Plus, they’ve achieved good parasite control.

Fraser King runs Shelterdale and Roundtop farms in Darfield, Canterbury. Totalling 1,100 hectares (ha), the two farms range from 270 to 880 m above sea level. Pasture is mostly ryegrass with red and white clover, with some tussock country on the hill block.

The King’s stock approximately 3,300 ewes and 300 breeding beef cows. They also graze 300 dairy heifers and winter 1,100 to 1,200 dairy cows. Crops include 24 ha of red and white clover (a finishing crop for lambs) and barley.

Fraser describes their main challenges as climatic with dry summers and snow in winter, and having drench resistance in sheep.

“Being part of that resistance trial was a good education process,” he says. “We’re now committed to keeping on top of drench resistance, aware that blanket capsule treatments don’t work for
our system.

“We refine our animal health plan annually in consultation with our vet. Then we cross check the plan with PGG Wrightson vet Jason Leslie and our Technical Field Representative, Sam Jarrett, both of whom actively support us in achieving good results.”

Lambs are drenched with the triple active drench every 28 days from late November through to early April. In late April/early May they are dosed with Zolvix Plus as a knockout drench.

Zolvix Plus contains the novel chemical monepantel and abamectin which offers premium parasite control, helping to protect the efficacy of other effective routine drenches¹. Sam recommends Zolvix Plus as a quarantine drench to people trading stock and as a knockout treatment for young sheep at the end of summer.

Every five years the Kings do a faecal egg count reduction test with the last one being in 2018. “We test to make sure resistance hasn’t worsened and to check the efficacy of the drench families,” Fraser explains.

“Results show that Zolvix Plus is highly effective. We trust it 100 percent. As an exit drench, we know it cleans out any worms that the main drench has not. As a quarantine drench, it enables us to get stock from anywhere, treat them once and know they’re clean.”

¹Elanco. (2020). Zolvix™ Plus Broad Spectrum Oral Anthelmintic for Sheep and Cattle. https://www.elanco.co.nz/products-services/sheep/products/zolvix-plus.