Sperm separation allows scientists to choose sex of calves

SCIENTISTS have used a technique for separating individual sperm cells to produce the first calves whose sex has been pre-determined.

The sex of six calves born last summer - three male and three female - was determined before fertilisation using the technique, which scientists predict will be widely used within a few years.

Small differences between sperm carrying the male 'Y' chromosome and those bearing the female 'X' chromosome enabled a sophisticated sorting device to separate the two types of sperm cell at the rate of about 2 million an hour. With the help of techniques routinely used for in vitro fertilisation of animal embryos, scientists fertilised bovine eggs with 'Y' sperm to produce male calves and with 'X' sperm to make female calves.

Cattle farmers could find the technique helpful in skewing the natural 50:50 ratio of males to females in their favour - dairy farmers want a ratio of one female replacement calf for their herd to three bull calves to sell for beef and beef farmers prefer bull calves only.

In this week's edition of Veterinary Record, scientists from a Cambridge biotechnology company, Mastercalf; the Institute of Animal Physiology and Genetics Research, also in Cambridge; and the US Department of Agriculture in Maryland, publish details of the research that led to the birth of the six Holstein Friesian calves. Professor Chris Polge, scientific director of Mastercalf, said pre-determining the sex of embryos had occurred on a limited scale on other animals, such as rabbits, but this was the first time it had been done in cattle. However, the procedure is complicated and large- scale trials are necessary before the idea could be adapted for commercial use. 'This may take two years,' he said.

David Cran, the leader of the scientific team at Mastercalf, said that farmers would be able to choose the sex of their calves with an accuracy of greater than 90 per cent. He said that having the power to alter the sex ratio of new-born calves - attempts were first made 75 years ago - 'will cut calf wastage and the economic and qualitative improvements will work through to the benefit of the consumers'.

Mastercalf already sells unsexed beef embryos and the company believes that sexed embryos will increase the value of resulting calves. The company is now producing more than 100 grade- one sexed embryos for field trials plannned for farms in Scotland, Cheshire and Shropshire.

Professor Polge said there were no ethical problems with the new technique and denied that it was tinkering with life: 'I don't think we are tinkering with it so much as putting it together, to be used more effectively for what the farmer wants.' He stressed that the procedure did not involve genetic engineering but only in vitro fertilisation, which had been used for many years and had full ethical approval.

Start your day with The Independent, sign up for daily news emails
Have you tried new the Independent Digital Edition apps?
ebooksAn unforgettable anthology of contemporary reportage
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: 3rd Line Virtualisation, Windows & Server Engineer

£40000 - £47000 per annum: Recruitment Genius: A 3rd Line Virtualisation / Sto...

Recruitment Genius: Refrigeration and Air Conditioning Service Engineer

£26000 - £35000 per annum: Recruitment Genius: A successful national service f...

Recruitment Genius: Business Development Executive / Sales - OTE £25,000

£15000 - £25000 per annum: Recruitment Genius: This is an opportunity to join ...

Recruitment Genius: Sales Administrator - Fixed Term Contract

£17500 - £20000 per annum: Recruitment Genius: We currently require an experie...

Day In a Page

Syria civil war: Meet the military commander who says his soldiers will not rest until every inch of their war torn country is free of Islamist 'terrorists'

‘We won’t stop until Syria is back to normal’

Near the front lines with Islamist-controlled towns where Assad’s troops were besieged just last month, Robert Fisk meets a commander confidently preparing his soldiers for battle
The inside story of how Bill Clinton built a $2bn global foundation may undermine Hillary's chances

The inside story of how Bill Clinton built a $2bn global foundation...

... and how it may undermine Hillary's chances in 2016
12 best olive oils

Extra-virgin, cold-press, early-harvest, ultra-premium: 12 best olive oils

Choosing an olive oil is a surprising minefield. Save yourself the hassle with our handy guide
Rafa Benitez Real Madrid unveiling: New manager full of emotion at Bernabeu homecoming

Benitez full of emotion at Bernabeu homecoming

There were tears in the former Liverpool manager’s eyes as he was unveiled as Real Madrid coach. But the Spaniard knows he must make tough decisions if he is to succeed
Sepp Blatter resignation: The beginning of Fifa's long road to reform?

Does Blatter's departure mean Fifa will automatically clean up its act?

Don't bet on it, says Tom Peck
Charles Kennedy: The baby of the House who grew into a Lib Dem giant

The baby of the House who grew into a Lib Dem giant

Charles Kennedy was consistently a man of the centre-left, dedicated to social justice, but was also a champion of liberty and an opponent of the nanny-state, says Baroness Williams
Syria civil war: The harrowing testament of a five-year-old victim of this endless conflict

The harrowing testament of a five-year-old victim of Syria's endless civil war

Sahar Qanbar lost her mother and brother as civilians and government soldiers fought side by side after being surrounded by brutal Islamist fighters. Robert Fisk visited her
The future of songwriting: How streaming is changing everything we know about making music

The future of songwriting

How streaming is changing everything we know about making music
William Shemin and Henry Johnson: Jewish and black soldiers receive World War I Medal of Honor amid claims of discrimination

Recognition at long last

Jewish and black soldiers who fought in WWI finally receive medals after claims of discrimination
Beating obesity: The new pacemaker which helps over-eaters

Beating obesity

The new pacemaker which helps over-eaters
9 best women's festival waterproofs

Ready for rain: 9 best women's festival waterproofs

These are the macs to keep your denim dry and your hair frizz-free(ish)
Cycling World Hour Record: Nervous Sir Bradley Wiggins ready for pain as he prepares to go distance

Wiggins worried

Nervous Sir Bradley ready for pain as he prepares to attempt cycling's World Hour Record
Liverpool close in on Milner signing

Liverpool close in on Milner signing

Reds baulk at Christian Benteke £32.5m release clause
On your feet! Spending at least two hours a day standing reduces the risk of heart attacks, cancer and diabetes, according to new research

On your feet!

Spending half the day standing 'reduces risk of heart attacks and cancer'
With scores of surgeries closing, what hope is there for the David Cameron's promise of 5,000 more GPs and a 24/7 NHS?

The big NHS question

Why are there so few new GPs when so many want to study medicine?