AgResearch is offering sheep breeders first use of a new test which help farmers to identify sheep that are more resistant to parasitic worms.
Parasitic worms cost livestock farmers an estimated $300 million per year in lost production and treatment costs.
The growing resistance of worms to chemical drench treatments is also a concern.
That is driving efforts by some breeders to identify sheep that have natural resistance to worms so that they can build up flocks of sheep that won't require as much drenching.
AgRsearch has developed an easily applied test that identifies sheep with greater natural protection.
It measures levels of antibodies to worms found in sheep saliva.
The CARLA Saliva test, as it's called, has been successful tested on more than 7000 sheep this year.