Hormone Information
by Dr. Sandra Cabot
Hormones may be used to accelerate the growth rate of animals so that
they can reach market earlier. They may also be used to improve or manage
breeding programs. Natural and synthetic hormones are used. In some countries
inadequate monitoring and education of the users of these hormones resulted
in meat (both beef and chicken) and eggs to contain high levels of hormonal
residues. This caused health concerns in the population consuming these
foods including early puberty, cessation of puberty, breast development
and ovarian cysts in young girls. Some scientists believe that the potential
for hormones in food to cause metabolic and reproductive problems in humans
needs further evaluation.
Hormonal Growth Promotants (HGP) are in implants designed to slowly release
small quantities of hormones from the ear of cattle to the tissues. The
hormone is similar to natural hormone found in animal species and humans
or they mimic the effects of natural hormones. They can also act as hormone
replacements for castrated animals (steers, spayed heifers) HGPs increase
weight gain and the efficiency of food conversion in cattle.
Use of Hormones and Growth Promotants in Australia
Some HGP have been approved for use in Australia since 1979. The levels
of these hormones in meat, milk etc are tested for in the Commonwealth
Government's National Residue Survey program.
Australian authorities state that no growth promoting hormones are used
in the rearing of chickens. Estrogens were once administered to young
male chickens as a hormonal alternative to castration to produce sterile
roosters, however this practice was banned in Australia in the early 1960s.
Some antibiotics are used therapeutically if a chicken has some sort of
disease that can't be cured by normal methods. These are used under
veterinary prescription. But antibiotics are used in products called digestion
enhancers also known as growth promotants. What these antibiotics do is
adjust the gut in the chicken so it gets rid of the unwanted bacteria,
so the bacteria that aid the digestion of the chicken's food can proliferate.
They are used specifically for growth promotion.
Use of hormones in USA
Most of the beef raised in the United States today is produced with
the use of hormones of some kind and have been used for more than 40 years.
Low levels of hormones, delivered through pellets placed in animal's
ears, are commonly used as growth enhancers. The arguments for using hormones
in meat production are mostly economic. With hormones, conversion of feed
into meat is more efficient, thus theoretically lowering producer's
costs. In the United States, there are six FDA-approved hormones: three
naturally occurring hormones (estradiol, progesterone, and testosterone)
and their synthetic surrogates (zeranol, melengestrol acetate and trenbolone
acetate). There is an ongoing dispute on the subject of hormones used
in cattle. The US government and beef growers associations maintain that
the use of hormones as growth promoters is safe and has no adverse effect
on human health. However In 1988, the EU (European Union) prohibited of
the use of oestradiol 17 , testosterone, progesterone, zeranol, trenbolone
acetate and melengestrol acetate (MGA) for growth promotion in farm animals.
This prohibition applies to Member States and imports from third countries
alike. This had major implications for trade and has caused an ongoing
dispute. As a result the United States has opposed the EU prohibition
on the use of these hormones since its implementation.
Use of hormones in dairy cattle in the US
BGH stands for Bovine Growth Hormone, a substance naturally produced
by the pituitary gland of the cows. It is otherwise known as Bovine Somatotropin
(BST). The actual hormone injected into cattle is rBGH. R stands for recombinant
and means that it is a synthetic version of the natural hormone. This
hormone is marketed under the brand name "Posilac" Monsanto
is the only company that markets this hormone to the dairy industry. US
Food and Drug Administration approved Posilac in 1993. The hormone is
used to increase milk yields from the cow - however it can cause serious
health concerns for the animal which can then affect its milk supply in
other ways - namely increased udder infections leading to higher levels
of pus and infective matter in the milk.
Monsanto prints the following on the warning label on each package
of the hormone: "Cows injected with Posliac are at an increased
risk of clinical mastitis (which results in visibly abnormal milk). The
number of cows effected with clinical mastitis and the number of cases
per cow may increase. In addition, the risk of sub-clinical mastitis (milk
not visibly abnormal) is increased. In some herds, use of Posilac has
been associated with increases in somatic cell counts. Use of Posilac
is associated with increased frequency of use of medication in cows for
mastitis and other health problems."
Since 1993, there has been a National Drug Residue Milk Monitoring Program
to test raw milk for the presence of antibiotics-but only for antibiotics
in the penicillin (betalactum) family. Only about four times a year do
federal officials spot check samples of pre-processed raw milk from any
given state, looking for residues of an antibiotic outside the penicillin
family of drugs.
Read more about these on the website:
http://www.foxbghsuit.com
Hormone use in dairy cattle in Australia
A number of hormonal products are commercially available for use in
the improvement of reproductive performance of dairy cattle.
Prostaglandin
This hormone is injected into the cow. Use: synchronization - to bring
a group of heifers all into 'season' at once. Improving fertility,
Retained foetal membranes, ovarian cysts in the cow, treatment of non-cycling
cows, infections of uterus and induced abortion.
Progesterone
Vaginal implants (CIDR®) and a system of ear implant and intramuscular
injection (CRESTAR) are used in Australia. Only CIDR is registered in
Australia for use in lactating dairy cows.
Use: Synchronization of cows to all be on heat at once, improved conceptions
rates, stimulating the breeding state in non-cycling heifers and cows.
Gonadotrophin Releasing Hormone (GnRH)
Use: Improving conception rates, Ovarian cysts. Commercially available
GnRH products are either identical to the naturally occurring hormone
or synthetic.
Oestrogen
Used for preventing conception.
Corticosteroids
Use: Inducing calving, aborting calves, ovarian cysts - Corticosteroids
may be used in cases of cystic ovaries that do not respond to other treatments.
Bovine somatotrophin (also called rBGH)
Bovine somatotrophin is NOT used in Australia but is approved for use
in dairy cattle in the US (see above) and several other countries for
increasing milk production.
From Research Notes " Hormone treatments for better reproductive
performance" Dairy Research and Development Corporation.
Antibiotics
This is a group of drugs approved for use in animal led to stimulate
growth and improve feed efficiency (so that less feed is required for
growth) and also to reduce infection and stock loss. There is no doubt
that antibiotics are used widely in the Australian livestock industry.
The continuous in-feed use of antibiotics began in agriculture in the
early 1950s, especially in the pig, poultry, cattle and aquaculture industries.
They are administered to the animal via coating of feed grains, drenching,
injection or addition to water.
The use of antibiotics in food animals has been a human health concern
since the 1970s when American FDA first called for restrictions on antibiotics
used in animal feed.
Resistance of dangerous bacteria is proportional to use therefore overuse
of antibiotics in animals, especially as growth promoters, poses unnecessary
dangers to human health via the food chain. Resistance to antibiotics
is not harmful in itself, but it may create health hazards if humans become
infected with a strain of microorganism that cannot be controlled by available
antibiotics. In other words, antibiotics not working against bacteria
that they've managed to kill before.
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