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. U.S. 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 micro-organism that cannot be controlled by available antibiotics. In other words, antibiotics not working against bacteria that they've managed to kill before.