Hair exposes illegal hormone use in cattle
A new technique, developed by researchers at Rikilt, can now
detect the presence of forbidden hormones in the hair of cattle.
Unlike previously-used urine tests, which are unreliable because
the natural fluctuation of hormones in cattle is so large, the
new hair test is 100 percent accurate. If the hormones in question
are found in the hair, they were not naturally produced by the
animal itself.
“The hormones that we looked at are natural hormones,” says
Dr. Michel Nielen from Rikilt. “Boldenone and testosterone,
both powerful androgens found in commercial preparations, are
also manufactured by cattle themselves. If you test the animals’ urine
you find conversion products from the hormones, whether or not
they have been given synthetic hormones.”
The use of testosterone, boldenone and other growth hormones
is forbidden in the EU, because scientists fear that the consumption
of hormone-treated meat may adversely affect people’s health
in the long-term. Beef farmers, however, are less concerned with
the law, because they can earn more per cow if they use forbidden
substances. Thus, a black market for hormone products has arisen.
The ministry of agriculture tries to keep the situation under
control by carrying out checks of the cattle. Until now, however,
the available testing methods were imperfect. Nielen and his research
team, who published their findings in the Journal of Chromatography
B, Analytical Technologies in the Biomedical and Life Sciences,
have solved that problem by testing hair from cattle, rather than
urine.
Nielen’s new technique makes use of the fact that manufacturers
manipulate naturally occurring hormones. “In commercial
preparations containing natural hormones, the hormones have been
esterised,” explains Nielen. “The hormones are attached
to a fatty acid so that they circulate for longer in the body.
Enzymes remove the fatty acid from the hormone.” This process
happens so quickly that the esters do not show up in the urine.
But those particular enzymes are not active in the cattle’s
hair, so synthetic hormone esters are stored there unchanged.
Because the esterised versions of testosterone and boldenone
do not occur naturally, the scientists’ discovery makes
it possible to provide conclusive evidence that an animal has
been given forbidden substances. The new technique is also highly
sensitive – Nielen and his colleagues at Rikilt and the
University of Gent in Belgium found intact esterised testosterone
and boldenone in the hairs of cattle that been given one single
injection of illegal growth hormones two weeks earlier.
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