Australian Breeding Value release proves accuracy of genomic testing

The latest DataGene Australian Breeding Value (ABV) release has revealed that the top young genomic bulls from 2019 - those that hadn't been used in any herds and had no daughters - are now sitting at the pointy-end of the proven bull offerings.

It shows genomic testing of young bulls - using a sample of their DNA - is providing an accurate prediction of the bulls' genetic merit and the future performance of their daughters.

Genomic bulls were first ranked according to DataGene's Balanced Performance Index in 2019, which means this year is the first opportunity for these bulls to become proven, as they only now have daughters milking within various Australian herds.

This confirmation about the accuracy of genomics is not a surprise for DataGene extension officer Peter Williams.

This finding was further validation for the earlier adopters of genomics and evidence for those who were yet to explore the technology.

"The Australian dairy industry has made a substantial investment - through DataGene, Dairy Australia and DairyBio - to ensure the reliability of genomics, so dairy farmers and their breeding advisers can select bulls and heifers with confidence," he said.

"Breeding is a long-term business, decisions we make today shape our future, and that's why we must have the right breeding tools to make the best and most accurate decisions."

READ MORE: Genomics: dairy's quiet revolution

This week's ABV release showed:

Mr Williams said genomic testing was 80 per cent reliable - eight out of 10 times the genomic prediction was correct.

The other 20pc was split between bulls that performed better than their genomics predicted and those that performed worse.

"I liken genomics to the start of a footy season when you are selecting your top four teams," Mr Williams said.

"With genomics, your top four may not be one to four, but you can have confidence that they will be inside the eight and playing finals."

Of the Australian dairy farmers who use genomics, most use it to test their females.

This information then determines which females they retain and what ones they breed to sexed semen or beef.

But Mr Williams said bulls were "the pinnacle" of proof when it came to genomic testing.

"With females, there are only ever a limited number of calves from each animal, and you can never be totally sure how much the performance of that female is influenced by her environment," he said.

"For example, a heifer could have great genomics, but she breaks her leg or gets pneumonia, it may not be her fault that she doesn't have a productive life.

"But with bulls, they are used across many herds, in all different regions, and they are used in volume.

"The science really gets tested in the bull sphere and it has proven its value to the Australian dairy industry many times over."

South-west Victorian dairy farmers Dale and Karen Angus are among those genomically testing their young females.

As a result, deciding which animals to retain for their milking herd has become easier for the Ondit, Vic, farmers.

They are also making more informed and confident breeding, culling and bull selection decisions.

The couple began genomic testing their young stock four years ago.

The information gathered from these DNA tests is used alongside herd recording and visual assessments of animals to make herd management decisions.

"Genomic testing helps us to make informed, data-supported decisions about who stays and who goes from a genetic perspective," Mrs Angus said.

READ MORE: More than 60,000 dairy females genomically tested in Australia in 2021/22

The final decision is based on genomic data and a visual assessment of the animals made by Mr Angus.

The Anguses milk 400 autumn-calving Holsteins with their children Charlotte, 10, Indianna, 9 and Clancy, 4, in a predominantly grazing system, north of Colac, Vic.

Genomic testing was introduced to the Angus family when they participated in the Dairy Australia Focus Farm program.

At the time they were intrigued by how other farmers were selecting heifers for the export market.

What began as a "casual lunchtime discussion", on the sidelines of a Focus Farm meeting, has morphed into an important part of their farm and a contributing factor to their business progression.

The latter benefit is something they attribute to making more informed decisions with the genomic data.

Thanks to genomic data "taking away the guesswork," the couple have also felt more empowered in discussions with breeding advisers.

"We've developed a much broader understanding of genetics, certainly this year and last year, and it has helped us make decisions about the bulls we use," Mrs Angus said.

"We understand the data a lot more, opposed to having catalogues put in front of us.

"We make our own decisions.

"It's our business, not their business, and at the end of the day we need to be comfortable and confident in each decision."

The Anguses use DataGene's Balanced Performance Index (BPI) and consider several traits when selecting bulls and evaluating their heifers.

The traits they concentrate on include fertility, milk fat and protein percentage, yield and survival.

BPI has the "most weighting" but fertility is a close second.

"We rank them by BPI first and then look at individual traits," Mrs Angus said.

"For us, fertility is something we are striving to improve in our herd since we started on our own seven years ago."

Practically, this means if there was a "toss-up" between two high BPI animals, the one with the higher fertility would be selected.

The couple choose to use tissue sampling for their genomic testing because it has a lower risk of contamination and incorrect sample collection.

All calves are dehorned, freeze branded and have the tissue sample - for genomic testing - collected at the same time.

When it comes to deciphering their genomic data, the Anguses found the colour-coding in the report from their genomics service provider was a helpful visual tool to enable quick analysis of the results.

The number of heifers retained is determined by the number of replacements required.

The Angus family are looking forward to milking more genomically tested cows as increasing numbers of tested calves move into the herd.

They believe that the information generated by genomic testing will inform more of their breeding decisions as a higher percentage of the milking herd is tested.

They believe it will improve their business bottom-line because of its ability to improve their genetic base.

"Genetics might only be a small part of our business, but it is often the one percenters that determine how profitable and sustainable our business is," Mrs Angus said.

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