London: Scientists have for the first time
created genetically modified cattle that produce milk with the
same properties as human breast milk, a breakthrough that they
claim will boost the nutritional value of cow milk.
A team, led by the China Agricultural University, has
successfully introduced human genes into 300 cows to produce
"human" milk which is known to contain high quantities of key
nutrients that can help to boost the immune system of babies
and reduce the risk of infections.
The transgenic animals are physically identical to
ordinary cows, say the scientists.
According to them, milk from herds of genetically
modified cows could provide an alternative to human breast
milk and formula milk for babies, which is often criticised as
being an inferior substitute.
Prof Ning Li, the scientist who led the research and
director of the State Key Laboratories for AgroBiotechnology
at the China Agricultural University, has said their work has
shown it was possible to "humanise" cows` milk which would be
as safe to drink as milk from ordinary dairy cows.
"The `human-like` milk will provide much higher
nutritional content. It tastes stronger than normal milk. We
aim to commercialise some research in this area in coming
"For the `human-like milk`, 10 years or may be more
time will be required to finally pour this enhanced milk into
the consumer`s cup," `The Sunday Telegraph` newspaper quoted
him as saying.
In their research, the team used cloning technology to
introduce human genes into DNA of Holstein dairy cows before
the genetically modified embryos were implanted into surrogate
cows. They said they were able to create cows which produce
milk containing a human protein called lysozyme.
Lysozyme is an antimicrobial protein naturally found
in large quantities in human breast milk. It helps to protect
infants from bacterial infections during their early days.
They created the cows that produce another protein
from human milk called lactoferrin, which helps to boost the
numbers of immune cells in babies. A third human milk protein
called alpha-lactalbumin was also produced by the cows.
The scientists have also claimed they have boosted
milk fat content by 20 per cent and have also changed levels
of milk solids, making it closer to the composition of human
milk as well as having the same immune-boosting properties.
"Our study describes transgenic cattle whose milk
offers the similar nutritional benefits as human milk. The
modified bovine milk is a possible substitute for human milk.
It fulfilled the conception of humanising the bovine milk,"
Prof Li wrote in the `Public Library of Science One` journal.
However, critics have questioned the safety of milk
from GM animals.
Helen Wallace, Director of biotechnology monitoring
group GeneWatch UK, said: "We have major concerns about this
research to genetically modify cows with human genes. There is
a question about whether milk from these cows is going to be
safe from humans."