Internal parasite control – a team effort

When it comes to managing internal parasites on farm, Bog Roy Station stock manager Danny Brown says the key step is a drench resistance test.
Wednesday, 7 June 2017

Danny has been at 2700 hectare Bog Roy near Otematata for the past two years and took himself along to a Beef + Lamb New Zealand Wormwise workshop about a year ago. He says the take home message was clear – that a drench resistance test is a must. 

“If you haven’t already done one, start from there.”

After the workshop, Bog Roy had the test done and discovered the two main drench families they had been using were only 75-85 per cent effective. 

The operation runs 4200 Merino ewes, lambing mid September. Lambs are finished on the property; once they reach 40kg liveweight, they are shorn then processed.

Ineffective drench buffer

Danny says Bog Roy was buffered from the full effects of ineffective drench, because it uses specialist crops – lucerne and red clover – for lamb finishing. Furthermore, the lambs are not forced to graze pastures down low. This keeps them clear of the bottom 20mm of the sward, where the bulk of worm larvae lie.

“Through good management of pastures and leaving a good residual, we were avoiding the full impact of the drench not working properly.”

The operation also has 85 beef cattle – used for pasture management and to “hoover up” larvae.

Danny was so impresed with the workshop, he attended a second time. 

“I almost got more out of the second one, because of the repetition. I made lots of discoveries.”

Prior to the workshops, Danny had very little knowledge around internal parasites and says he still has a lot to learn. 

The objectives

“I used to think the objective was trying to kill all the internal parasites on the property. Now I realise it’s about keeping the ‘common’ population of internal parasites – that is, the non-resistant ones – as the main population. What you don’t want to do is use technology and practices that encourage the resistant population to thrive.

“We now use practices like refugia, which keeps the common worm population as the main one, and make better use of cattle. We have also moved to strategic use of a triple-active drench – but alongside these practice changes.”

Being well-informed

Danny believes it is important for everyone on farm – from owners, to shepherds – to be well informed and aware of best practice. “That way, the team understands and uses tools – such as better pasture management, faecal egg counts and drench – correctly, resulting in better animal welfare and sustainable practices.

“From a shepherding point of view, you should always be looking to further your knowledge and skills regarding the welfare of livestock. The Wormwise workshops provide an excellent opportunity to do this.” 

Wormwise workshop

If you’re interested in a Wormwise workshop being held in your area, email B+LNZ Extension Manager, Laura Gray