RESEARCH The brushtail possum is an introduced predator from Australia. It is the main vector (transmitter of TB in cattle and deer) in New Zealand.
TB battles won, not the war By Samantha Tennent
Scientists have been fighting the war on TB eradication for decades and can finally see the finish line.
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OSPRI lead veterinary epidemiologist Dallas New has been leading the team working on eradicating TB and says while they have many challenges, good progress is being made.
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earing the home straight for TB eradication in New Zealand, the team at Ospri know they need to keep the accelerator flat to the floor. With close to 1700 herds infected 30 years ago, it almost seemed impossible, but there are less than 40 herds infected now. “It’s great we’ve made so much progress, but there are a few challenges with only small numbers of infected herds left,” Ospri lead veterinary epidemiologist Dallas New says. “We need to access the land where possums preside and when there were a lot of areas to cover if we had trouble accessing one area, we had the option to go somewhere else. “But now that we’re down to the remaining 30 to 40 infected herds, we need access to areas that are tougher to reach.” The goal is to have TB eradicated from livestock by 2026, but NZ presents an interesting challenge for TB. In the 1800s, both cattle and possums were
imported to NZ and some cattle were infected with TB. When the number of possums exploded, bovine TB jumped into possums. “This hasn’t happened anywhere else, so that’s what makes the TB situation so tricky, we have to get rid of the possums that are spreading the TB,” she says. The best combat against possums includes traditional pest control methods on the ground and in the air, as well as wildlife surveys. Most control is done using ground-based traps and handlaid toxins, but in some areas the most efficient is aerial control. “There are some areas that just aren’t accessible to reach for ground control,” she explains. “Applying baits containing biodegradable 1080 from helicopters is efficient, cost-effective and extremely successful at reducing possum numbers to low levels.” “And it’s our best defence to get those numbers down, we know we can expect to eradicate TB from an area if we
DAIRY FARMER
December 2021
