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5-Animals: Protein-rich milk from GE cows could speed dairyprocessing



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                                  PART I
-------------------------------- GENET-news --------------------------------

TITLE:  Clones to cut cheese costs?
        Protein-rich milk from modified cows could speed dairy processing
SOURCE: Nature, UK, by Hannah Hoag
        http://www.nature.com/nsu/030120/030120-15.html
DATE:   Jan 27, 2003

------------------ archive: http://www.gene.ch/genet.html ------------------


Clones to cut cheese costs?
Protein-rich milk from modified cows could speed dairy processing. 27
January 2003

Protein-rich milk from cloned, genetically modified cows could cut
cheese- making costs. Dairy manufacturers would need less milk to make
cheddar firm and ice cream creamy.

Two years old and living in New Zealand, the clones produce about 13
percent more milk protein than normal cows. They carry extra copies of
the genes for two types of the protein casein, key for cheese and yoghurt
manufacture1.

"The proteins are important. They allow milk to have a high protein
content, but to remain watery," says study leader Götz Laible of New
Zealand biotech company AgResearch. His team must now find out whether
the increase improves milk's calcium content or its ability to coagulate
before they seek approval to sell the clones to dairy farmers.

Most scientists believe that milk from cloned cows is no different to
normal milk. But they are less certain about the safety of milk from
genetically modified cows.

It depends on which gene has been added to the cow's DNA, says animal
reproduction specialist Will Eyestone of Virginia Polytechnic Institute
and University in Blacksburg. For instance, some cows are altered to
produce pharmaceutical products. A drug could pose a health risk if it
seeps into the milk.

Laible's cows might be less worrisome - they don't produce foreign
proteins, just more of natural ones. "You're upping the nutrient value,"
says Roberts. "This is unlikely to be a problem." But further testing
will have to confirm the milk's safety, he adds.

"A lot of cloned milk is being poured down the drain," says Michael
Roberts, an animal biotechnologist at the University of Missouri-
Columbia. Food products from transgenic and cloned animals, and their
progeny, are not legally available in many parts of the world.

The US Food and Drug Administration has yet to issue its guidelines on
the matter. Until then, companies producing cloned cows have volunteered
not to sell their milk.

Laible created the high-output cows by inserting casein genes into the
DNA of a cell taken from the 60-day old fetus of a female dairy cow. The
researchers then transferred the nucleus into unfertilized cow eggs. Of
the 126 modified embryos, 11 cows survived until after weaning.

References

Brophy, B. et al. Cloned transgenic cattle produce milk with higher
levels of (b)-casein and (k)-casein. Nature Biotechnology, published
online, doi:10.1038/nbt783 (2003).



                                  PART II
-------------------------------- GENET-news --------------------------------

TITLE:  GM cows to please cheese-makers
SOURCE: New Scientist, UK, by Emma Young
        http://www.newscientist.com/news/news.jsp?id=ns99993307
DATE:   Jan 26, 2003

------------------ archive: http://www.gene.ch/genet.html ------------------


GM cows to please cheese-makers

Cows genetically modified to produce high-protein milk for the cheese
industry have been created in New Zealand. It is the first time that
cow's milk has been engineered to improve its quality, rather than to
contain profitable pharmaceuticals.

The cows possess additional copies of genes for two proteins, beta and
kappa casein. As a result, their milk contains between up to 20 per cent
more beta-casein and twice the amount of kappa-casein as milk from
ordinary cows.

This should allow cheese-makers to produce more cheese from the same
volume of milk. The manufacturing process should also be quicker, due to
the faster clotting times associated with the higher protein levels.

"Basically, cheese is casein," says Goötz Laible, who led the work at the
Ruakura Research Centre in Hamilton. "An increase in casein would
certainly be of great value to the dairy industry, because farmers are
paid on the basis of how much casein is produced in the milk."

But others believe public opposition to eating food from GM animals could
be even greater than that to GM crops, potentially keeping cheese made
from the milk off the market.

"The rejection of genetically engineered food is very strong, in
countries like China as well as the West. And if people don't want to eat
it, no one will produce it - we've seen that clearly in Europe," says
Vanessa Atkinson of Greenpeace Australia. It would be important to ensure
that any GM animal ingredient would be labelled, she says.

Highly optimised

Laible's team created a number of transgenic cell lines, each containing
up to 39 additional copies of the casein genes. These were fused with cow
eggs, and the cloned embryos produced were implanted in cows. Of 11
healthy offspring, nine produced increased amounts of casein.

Dairy cattle breeders have long selected for high casein production in
conventional breeding. "We were not even sure that it would be possible
to increase the protein output in such a highly optimised genetic
background. So we got a good result, " Laible says.

He thinks it would take about four years to introduce the additional
genes into the dairy cattle population on a large scale. Products made
from the milk could then be on sale within 10 years.

But in some countries there has been strong opposition to other
transgenic food animals, such as the super-size salmon created by US-
based Aqua Bounty Farms.

In September 2002, a report from the UK's Agriculture and Environment
Biotechnology Commission recommended a series of new laws restricting the
ways in which animals could be genetically engineered. The chairman
admitted this was partly a bid to avoid a repeat of the public relations
disaster that GM crops produced in Europe.

Journal reference: Nature Biotechnology (DOI: 10.1038/nbt783)