Helping farmers fight TB

It's a gentle winter’s day deep in the Clutha hinterland, near the Catlins.

Even so, the wind bites on the top of Peter McNab’s 3,400ha farm as he surveys his land and gazes to the south towards Antarctica.

McNab knows this well because he was born and raised in the area. He’s one of those long stayers, committed to his land, his family and his community.

Recently, he retired from the OSPRI committee (formerly the Regional Animal Health Committee - RAHC) after serving for more than 30 years, through the toughest times, when bovine TB was rife in Otago.

When he talks about his legacy as a long serving committee member, McNab is very humble.

“I ate an awful lot of pies and had a lot of lovely lunches. I was chairman of the committee for a few years and my forte was keeping everyone working together, understanding it but trying not to distort what needed to get done.

“There has been a whole lot of people and I’ve been a cog in the wheel for booting TB out of Otago.”

McNab had TB in his herd in 1989, back when most people didn’t even know that possums were linked to TB.

One of the reasons he joined the RAHC as it was then called was because his ‘house’ was on fire (so to speak) and his mind needed to be focussed.

TB was initially detected on his neighbour’s farm (he had 219 cattle with TB one year) and then shortly after that, TB was detected on the McNab farm and other neighbouring farms.

TB is a serious animal health problem, so can have a real impact on the farm, and left unchecked can be a threat to our farming industry’s reputation overseas.

When McNab got a phone call about a meeting where people were expressing concern about the possum problem, he put his hand up to volunteer. At the age of 32 in 1989 he was the youngest member.

By the mid-1990s, bovine TB had reached every corner of Otago and herd infections peaked at around 300.

“We had great support from the Animal Health Board (now OSPRI). Their staff were passionate about the cause, and it was great to be involved. At the time, there was a lot of work to see the result we achieved now, from a TB perspective. It’s been a great journey.

“Farmers are more likely to follow and listen to farmers, and because there were a number of people who had had TB and really understood the importance of knocking it back, we were able to get the following we needed to get a levy in place by the mid-to late 1990s.”

The key to the success of the journey was a lot of possum control both ground and 1080 aerial control, reflects McNab.

“You can TB test all you like, but unless you get rid of the possums through possum control, they will just reinfect the cattle. We also worked out quickly that if a property had TB through infected possums, you didn’t just need to control that property you had to go two properties on either side. You were chasing your tail if you just did individual properties, you had to do areas.”

The other key to success was the tried-and-true threelegged stool approach: movement control, TB testing, vector control, movement control.

“If you did get a reactor (animal that tested positive for TB), you couldn’t move animals without having stringent controls about moving and then once they moved, you had to re-test again to make sure they hadn’t gone through the test and not been detected.

Now that McNab is ‘semi-retired’, his oldest son is running the beef, sheep and deer farm.