Photo of frozen semen

How breeding technology is shaping the livestock industries

In 1995, an ordinary-looking lamb was born from a conventional Merino sheep.

But Larry the lamb was anything but ordinary. Larry made history as the world’s first sex-selected sheep.

Scientists at the University of Sydney always knew they were going to have a baby. They had employed a process that divided mutton sperm into male and female, and they chose to produce a male.

Photo of a man holding a bucket with a lamb inside.
Larry the Lamb was the first sex-determined sheep born using sexed sperm.(Supplied by: University of Sydney)

Scientists used a technique discovered in the United States in 1989, when Dr. Larry Johnson developed a method to separate female (X chromosome) and male (Y chromosome) living sperms based on their DNA content.

Johnson had effectively turned nature upside down. Until then, nature had determined whether you were born a boy or a girl.

Sperm of sexed cattle

American scientists made their breakthrough using rabbits and then successfully applied the technology to cows and pigs.

Of course, it was the livestock industries that were the biggest beneficiaries of this brave new world, and it was the dairy farmers who embraced it the most.

They want the calves to replenish their milking herds.

The largely unwanted male calves are known as bobby calves and can be sold for slaughter from five days of age.

Half a dozen newborn dairy calves in a barn.
Dairy farmers want calves to replenish their dairy herds and often have to destroy the males.(ABC Rural: Lachlan Bennett)

Dairy Australia estimates that around 300,000 bobby calves met that fate nationwide last year.

Around the world, there is growing opposition to bobby calves. Many countries have banned the trade.

New Zealand is introducing tougher restrictions and many believe Australia will soon follow.

Reduce waste animals

Improved animal welfare is one of the main reasons why more and more Australian farmers are using “sexed” seed.

“The main type of incentive to use sexed sperm was the plight of the poor Jersey male calf. They really have no value in our industry,” said Tess Butler, a veterinarian and dairy farmer in Jindivick, east of Melbourne. .

“Unfortunately, they are slaughtered at about five days of life, off to the slaughterhouses, which is something we don’t really agree with and we really want to change.”

Photo of a woman standing in front of a tractor.
Tess Butler says sexed sperm will mean fewer male calves sent to slaughter.(ABC landline: Tim Lee)

Right now, it’s birthing season. In the farm’s calf rearing barn, there is a growing number of young Jersey calves.

So far, their use of sexed sperm is getting better results than expected.

“Last year, we ran around 10% bulls, which is what we were promised, which is great,” Butler said.

“We’ve only had a week of calving this year, but we have about 5% bull calves, so that’s great too.”

“The technology has definitely improved over time,” said farmer Rowen Foote.

“We are seeing much better conception rates since early 2004 until now. It has been huge.”

Photo of a man smiling in front of the dairy cows.
Milk farmer Rowen Foote has been using sexed semen since 2004, mainly on heifers, but in 2017 she started using it with her milking herd.(ABC landline: Tim Lee)

Mr. Foote runs a large family-run dairy in Fish Creek in South Gippsland. Contrary to bobby calves, he was one of the first to adopt the use of sexed sperm.

Sex selection also means it can sell surplus dairy heifers to the lucrative export market.

About a quarter of Australian breeders currently use sexed semen. In the UK, the figure is now 50%.

“So the whole area of ​​sexed sperm is evolving at a very fast pace, and mainly it has been so much research and successful conception rates that are driving that effort,” said Paul Douglas of the global company ST Genetics.

British milk producers gained access to sexed sperm in 1998, when the British company Cogent made the first commercial sales of sexed sperm from dairy bulls.

In the early years it was expensive to use, conception rates weren’t always good, and there was a limited range of bovine genetics available.

Photo of a man talking.
Brad Aitken says there are a number of reasons for the growing popularity of sexed sperm, including lower birth weight calves, so fewer problems at calving. (ABC landline: Tim Lee)

In 2017, US company ST Genetics acquired a majority stake in Cogent.

The company is rapidly expanding its sperm sorting facilities around the world.

“I think there are now over 40 labs in 33 countries, most of which work 24 hours a day, seven days a week,” said Peter Semmens, head of the company’s Australian branch.

“The product is getting better by the day, and the discerning breeder out there or the discerning farmer are making some pretty smart decisions,” said Brad Aitken, whose company supplies genetics to cattle ranchers across Australia.

Far-reaching benefits

To date, ST Genetics has focused on dairy genetics. But the company is targeting the Australian beef industry, which is rebuilding after severe droughts and floods.

Breeding more females through gender selection can accelerate that rebound.

The company has other species in its sights. Sheep producers are embracing the use of sexed sperm, and pork and goat producers are ready to join them.

Photo of two smiling men standing on a farm.
Pete Semmens (left) and Paul Douglas (right) say technology can play a huge role in herd or herd regeneration by regenerating more females.(ABC landline: Tim Lee)

In the future, genus selection could be used to strengthen populations of endangered animals by producing more reproductive females.

And this new frontier of animal production is getting closer and closer to home. The company is experimenting with the sorting of dog sperm.

“They could be ideal working dogs who get involved in a sexed sperm situation. Who knows?” said Mr. Douglas.

Watch this story on ABC TV’s landline at 12:30 pm on Sunday or on ABC iview.

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