Scientists backing animal feed rethink By Li Jing (China Daily) Updated: 2005-09-12 05:44
In the face of increasing concerns over the controversial use of antibiotic
growth promoters in animal feed, agricultural researchers in China are trying to
find possible replacements and reduce the need for antibiotics in factory
farming.
It is common knowledge that bacteria can become resistant to antibiotics
through overexposure. Ordinary people may be cautious when they take antibiotics
to treat infections, but few realize that the animals from which our meat and
dairy come are usually fed an abundance of antibiotics.
In fact, about half of the antibiotics used worldwide are given to farm
animals, largely used at a subtherapeutic level to fatten them or to guard
against infections that can spread through barns and pens, according to the
World Health Organization.
Tong Jianming, a professor with the Institute of Animal Science under the
Chinese Academy of Agricultural Sciences, said Chinese researchers have already
focused attention on the potential hazards of antibiotic growth promoters, which
speed pigs, poultry and cattle to market but also speed the development of
bacteria that are resistant to antibiotics.
Tong is now presiding over a national research project developing and
utilizing naturally occurring molecules such as bacteriocins, antimicrobial
peptides and enzymes, which may serve as possible replacements for antibiotics.
The project, which started in 2000 and is due for completion by the end of
the year, has made several breakthroughs, said Tong.
"My team has applied for patents for five products we have developed, and has
put them on the market. Practice shows that these biological feed additives have
some encouraging effects to promote growth.
"One example is a Beijing-based egg company that introduced microbe
preparation as feed additives and phased out antibiotics and chemicals in
chicken feed. The 'green' eggs these hens produced had a better taste and
organic features, that helped increase the company's sales by 30 per cent over
the past four years," said Tong.
He said antibiotics had played a significant role in the development of
modern animal husbandry. However, the routine low-dosage use of antibiotics on
factory farms has been linked to increased incidence of antibiotic resistance.
The dose of aureomycin - a widely used antibiotic in feed - has had to be
increased by nearly 10 times over the past 50 years.
In the 1950s, the recommended dose of aureomycin was 10-35 milligrams per
kilogram of feed, but now the amount is 100-150. In some areas, the dosage is
even higher than 150.
Tong said developing non-antibiotic alternatives was an urgent task.
Tong's point was echoed by Dr Pearse Lyons, president of the US-based Alltech
Biotechnology Co Ltd, which is also engaged in the research and production of
possible replacements for growth-promoting antibiotics.
Lyons said, "People have now paid more attention to feed safety, as what
animals eat will go into humans."
Gu Junhua, general engineer with the China National Centre for Quality
Supervision and Test of Feed under the Ministry of Agriculture, said China is
one of the world's major suppliers of animal products. However, most of the
country's livestock rearing farms rely heavily on antibiotics, which seriously
hamper the export of animal products to countries that set strict restrictions
on the use of growth-promoting antibiotics.
(China Daily 09/12/2005 page3)
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