There are claims that New Zealand is lagging behind other countries in adopting on-farm genomic screening technology.
Genomic screening is used to identify calves with the greatest genetic potential, enabling breeding decisions to be fast-tracked.
- The scientists calling for genetic modification in New Zealand
- NZ needs to rethink genetic engineering stance - experts
David Fullerton and his wife Pip, along with their sons Alex and Dean, milk almost 600 Holstein Friesians at Ngahinapouri near Hamilton. They also use genomic testing.
Fullerton said the technology means they can tell before a heifer calf is weaned if it's going to grow into a profitable, high-producing dairy cow.
"Genomic screening has been one of the biggest advancements in cattle breeding in the last 100 years," he said.
"It dramatically shortens the time it takes to identify important traits in an animal from five years to several months."
He said those traits vary from a cow being a more efficient converter of feed into milk solids, through to being heat tolerant.
The Fullerton's import embryos from Canada, the United States and Holland and are world-renowned for their genetics work.
Their stud, Waipiri Holsteins, holds the New Zealand record for the top registered three-year-old Holstein Friesian cow, which produced 1,292 kilograms of milk solids in the 2009/10 season.
They rear 160-200 replacement heifers a year and plan to genomic test 25 percent of them using a service offered through Holstein Friesian NZ.
"We've exported bulls to Tanzania, China, Malaysia and South America and are exploring opportunities to sell semen into Zimbabwe, Vietnam, the Philippines and Ecuador."
"Most farmers in those countries can't afford cooling fans, so we need to know our animals can tolerate the heat."
"Genomic testing has huge potential to increase dairying's profitability and we'd be foolish to ignore the information it provides," said Fullerton.
Currently, the annual value of genetic gain in the New Zealand dairy herd is worth around $11 per cow.
The figure is almost twice as high in Australia, where the use of genomic screening is more widespread.
Holstein Friesian NZ president Hennie Verwaayen also uses genomic screening.
Verwaayen and his wife Kerri, and their children Harvey and Lucy, milk 380 Holstein Friesian cows near Dannevirke.
The couple first used genomic testing in 2016 on four calves born from embryos imported from the United States.
"Two of the calves were bulls. They were both almost identical to look at, but the testing revealed one was among the top five in the world for certain traits," he said.
The Verwaayen's now use the service provided through Holstein Friesian NZ to test all of their overseas-sired replacement heifers.
"If the results identify genetically superior heifers, we can do embryo transfer work with them or mate them using sexed semen," he said.
"The test has the added advantage of verifying parentage, which improves the accuracy of our records and means we don't have to pay for a separate DNA test."
However, he said more farmers should be using the testing and enjoying the same gains.
"New Zealand is languishing behind in adopting this technology and our association is endeavouring to change that."