The sexual revolution on the farm is hitting home

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

But Larry the lamb was no ordinary thing. Larry made history as the world’s first breedable sheep.

Scientists at the University of Sydney always knew they would have boys. They applied a process that separates ram sperm into male and female and chose to produce a male.

Larry the lamb was the first sheep to be born with sex-assigned sperm.(Courtesy: University of Sydney)

Scientists used a technique discovered in the United States in 1989 when Dr. Larry Johnson developed a method to separate live female (X-chromosome) and male-producing (Y-chromosome) sperm by DNA content.

Johnson effectively turned nature on its head. Until then, nature determined whether you were born male or female.

Breeding cattle semen

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

Of course, the biggest beneficiaries of this brave new world were the livestock industry, and dairy farmers were the most receptive.

They want female calves to fill their milking herds.

Male calves, which are mostly unwanted, are known as bobby calves and can be sold for slaughter at five days of age.

Half a dozen newborn dairy calves in the nursery.
Dairy farmers want female calves to fill their milking herds and often have to cull the males.(ABC Village: Lachlan Bennett)

Dairy Australia estimates about 300,000 bobby calves met that fate across the country last year.

There is growing opposition to bobby calves around the world. Many countries have banned the trade.

New Zealand is imposing stricter restrictions and many believe Australia will soon follow.

Reducing animal waste

Improving animal welfare is the main reason why more Australian dairy farmers are using ‘sexed’ semen.

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

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

Image of a woman standing in front of a tractor.
Sexed sperm means fewer male bobby calves sent to slaughter, says Tess Butler.(ABC landline: Tim Lee)

Now is calving season. The number of young Jersey calves in the farm’s calf barn is growing.

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

“Last year we ran with about 10 per cent bulls, which is what we were promised, which is great,” Ms Butler said.

“We’ve only been calving for a week this year, but we have about 5 percent bull calves, which is amazing.”

“Technology has gotten better over time,” dairy farmer Rowen Foote said.

“We’re seeing much better conception rates from the beginning of 2004 to now. It’s been massive.”

Image of a smiling man in front of milk cows.
Dairy farmer Rowen Foote has been using sexed semen mainly in heifers since 2004, but in 2017 he started using it with his dairy herd.(ABC landline: Tim Lee)

Mr Foote runs a large family-owned dairy farm at Fish Creek in South Gippsland. Against Bobby calves, he was an early adopter of the use of sexed sperm.

Breed selection also means he can sell surplus dairy heifers to the lucrative export market.

About a quarter of Australian dairy farmers now use sexed semen. In the UK, the figure is now 50 per cent.

“So the whole field of sexed sperm is growing at a tremendous pace, and primarily because of that, a lot of research and conception rate success is driving that mark,” said Paul Douglas of ST Genetics Global.

In 1998, when the UK company Cogent made the first commercial sale of sexed semen from dairy bulls, British dairy farmers had access to sexed semen.

In the early years it was expensive to use, conception rates were not always good, and the available cattle genetics were limited.

Picture of a man talking.
Brad Aitken says there are many reasons why sexed sperm are becoming more popular, including that calves with lower birth weights present fewer problems at calving. (ABC landline: Tim Lee)

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

The company is rapidly expanding its sperm sorting capabilities worldwide.

“I think there are now more than 40 laboratories in 33 countries, most of them open 24 hours a day, seven days a week,” said Peter Semmens, who heads the company’s Australian branch.

“The crop is getting better every day and the smart breeder or smart farmer out there is making some pretty smart decisions,” said Brad Aitken, whose company supplies genetics to livestock farmers in Australia.

Comprehensive benefits

To date, ST Genetics has focused on dairy genetics. But the company is targeting Australia’s beef industry, which is rebuilding after severe drought and flooding.

Breeding more females through breed selection can accelerate this reversal.

There are other species in the sights of the company. Sheep producers are embracing the use of sexed semen, and pig and goat producers are set to join them.

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

In the future, breed selection can be used to increase the population of endangered animals by producing more breeding females.

And this new frontier of animal production hits close to home. The company is conducting experiments on the sorting of dog sperm.

“It could be the ideal working dogs mixed in with the sex sperm situation. Who knows?” said Mr. Douglas.

Watch this story on Sunday at 12.30pm on ABC TV landline or ABC iview.


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