Group 6: Renita F, Hillary G, Ben I, and Mariah M

The Negative Effects Growth Hormones and Synthetics Have On Farm Animals



For years growth hormones and synthetics have been used in farm animals to boost their production of food and dairy products. The boost in production has lead to an abundance of meat and dairy products being produced, but there are negative effects that came along with the benefits. These negative effects have an effect on consumers, animals, and our environment. The damage it causes has an effect on the animal itself, consumer’s health, the economy where it’s sold, and on our ecosystem. There are pros and cons to everything in life, but the negative effects that are associated with the use of growth hormones And synthetics in animals, outweigh its benefits.

History/Background on Hormones in Beef and Poultry

According to a fact sheet from Cornell University, in the 1930’s people began experimenting with the substance found in a cow’s pituitary glands. They found that cows injected with the substance (bovine growth hormone) produced more milk. It was also found that the female sex hormone estrogen had an effect on the growth of cattle and chickens. It allowed the animals to grow bigger than average. Although it was proven that both types of hormones worked these new developments were not able to be used widely until later on.

People began introducing hormones in to animals produced for food around the 1950s. The chemistry of estrogen was examined and then they were able to reproduce estrogen synthetically. Diethylstilbestrol (DES) was one of the first synthetic estrogens that was developed and used to increase the growth of animals. It was also used as a drug for humans until it was proven to cause cancer. As a result it was phased out in the 1970’s. The use of hormone, DES, is now strictly prohibited.

The bovine growth hormone (bGH) was not able to be reproduced on a mass scale until the 1980s. By using recombinant DNA technology they were able to reproduce pure bGH in large amounts. In 1993, the Food and Drug Administration allowed the recombinant bovine growth hormone (rbGH), also known as bovine somatotropin (rbST) to be used in cattle to help produce more milk in dairy cattle.

The United States use of growth hormones in food has increased over the years, especially in beef. According to the food pyramid, beef, milk, and chicken make up a large portion of an average person’s diet. For the US it is a growing issue because hormones are being used more and more in the US diet. According to GenetiChemistry, by 2008 a third of American dairy cows were injected with rBGH. This means people are exposed to hormones extensively.

Hormones We Use Today

The types of hormone used has changed and been developed to different forms over the years. Typically hormones are giving to cattle through an ear implant also called a pellet. It is placed under the skin of the ear. When the animal is slaughtered the ears are cut off and thrown away. The FDA does not require the type of hormones used to be on the labels of a package of meat. The USDA and FDA have approved six types of growth hormones in the cultivation of beef, and one more hormone used to increase milk productivity:

Natural Hormones

 Estradiol – female sex hormone used for increased rate of weight gain in beef calves and for increased rate of weight gain in cows fed in confinement
for slaughter.

 Progesterone – also a female sex hormone used to fatten cattle

 Testosterone – male sex hormone

Synthetic Hormones

 Zeranol – an estrogenic substance used to fatten livestock

 Trenbolone acetate – a steroid used to increase muscle growth and appetite in cattle.

 Melengestrol acetate – a synthetic growth promoter which makes the animals grow faster.

These hormones are currently only being used in beef and sheep. Contrary to popular belief, hormones are not used in the growth of poultry. There have not been
hormones used in poultry since the estrogen hormone DES. The U.S. has made it illegal for hormones to be used in poultry or pork.

Pros and Cons of Hormones

Growth hormones are used in beef by produces because it is believed to improve meat quality by increasing the development of lean meat and decreasing fat content. For farmers it also increases feed efficiency, allowing them to feed and reduce the cost of producing therefore reducing the price of meat and meat products for consumers. For example, if two cows were being fed the same amount the cow that is being treated with hormones would get fatter and bigger than a cow was not treated with hormones. The farmers spend less money on feeding therefore allowing them to sell meat for less.

Only a few other countries allow the use of the same hormones. There have been a growing number of concerns from consumer, scientist and organic groups about the use of hormones. Some of the concerns are: early puberty in girls, increase risk of breast cancer, and decrease the healthiness of humans. According to the Organic Consumer Association, every American who eats meat has been exposed to these hormones for over 50 years on a regular basis.

"The possible effects on human populations exposed to residues of anabolic sex hormones through meat consumption have never, to our knowledge, been studied. Theoretically, the fetus and the prepubertal child are particularly sensitive to exposure to sex steroids" (Swan.)
Some countries do not allow meat that has been treated with hormones to be used. In 1989, the European Union issued a ban on all meat from animals treated with steroid growth hormones. Therefore countries within the European Union do not allow the use of the hormone rbGH, for dairy cattle.

Harmful Effects on Farm Animals

In many occasions, the harmful effects of synthetics and growth hormones used in farm animals is only thought of as harmful to the humans. In reality, these synthetics and growth hormones are and can be extremely harmful to the animals as well. The harmful effects to the animals are often dismissed and it should be known that these treatments to the animals are inhumane and malicious. The most common and controversial artificial hormone that has been proven to have negative effects on animals is recombinant bovine growth hormone (rBGH).

Recombinant Bovine Growth Hormone (rBGH)

The hormone known as recombinant bovine growth hormone (rBGH) and also known as recombinant bovine somatotropin (rBST) is a hormone that is approved for use by the FDA in order to increase the production of milk. (Sustainable Table, 2008) “When injected into cows, rBGH increases milk production 10-15 percent and in some cases up to 40 percent. Approximately 17% of all cows in the US are given the artificial growth hormone.” (Hansen, 1998) This hormone is extremely controversial due to the conflicting beliefs of whether it is safe for animals or not. The use of recombinant bovine growth hormone has been banned in Japan, Canada, Australia and the European Union due to the harmful effects on both animals and humans. (Sustainable Table, 1998)

Harmful Effects of rBGH on animals

The Canadian Government has extensively researched the usage of the hormone rBGH in animals to produce a greater amount of milk and found numerous negative effects in animals, humans and the environment; and has released studies proving these findings. The Canadian government also claims that the FDA did not release findings that this hormone is detrimental to cattle’s health. Monsanto performed a test on ninety mice and the findings of this study were never published. The belief is that the study showed all the negative effects and the manufacturer did not want this to be known. “FDA says that, before a drug can be approved for use in animals, "the company must show that the drug is effective and safe for the animal."[2,pg.875] The Canadian government report (pg. 29) says, "Evidence from the animal safety reviews were [sic] not taken into consideration. These studies indicated numerous adverse effects in cows, including birth defects, reproductive disorders, higher incidence of mastitis.” ( Chopra, 1998) As I just stated, the usage of rBGH included so many negative effects on the cows. One such effect, mastitis, is a painful bacterial infection of the udder which causes inflammation, swelling, as well as the appearance of pus and blood secretions into milk. (Sustainable Table, 2008) In order to treat mastitis outbreaks, the dairy industry relies on antibiotics. (Sustainable Table, 2008) Critics of rBGH believe that the increase in antibiotic use (which contributes to the growing problem of antibiotic resistant bacteria) and inadequacies in the federal government's testing program for antibiotic residues in milk. (Kastel, 1995) The FDA relies on the usage of pasteurization to terminate bacteria, hormones and antibiotics in milk. (Sustainable Table, 1998)

As a result of all the negative effects that the hormone rBGH, the manufacturers went through extreme measures to make sure that the hormone was approved. "There are reports on file that Monsanto pursued aggressive marketing tactics, compensated farmers whose veterinary bills escalated due to increased side effects associated with the use of rBST [rBGH], and covered up negative trial results. All the four U.S. manufacturers [Monsanto, Eli Lilly, Cyanamid and Elanco, with only Monsanto actually marketing a product] refused to disclose the lists of their research grants to U.S. universities."

Without such lists, one could not inquire what effects (if any) had been revealed by animal experiments.” (OCA, 1998) It is evident that the company was more interested in the benefits they would receive for developing the product such as profit and credibility were of much more concern than the detrimental effects rBGH created in animals, humans and the environment. The United States and the FDA have ignored all warnings and signs that prove this drug is harmful. Numerous countries have banned it and studies proving the harmful effects have been published to prove it yet the drug is not banned. Starbucks has banned the usage of products that contain rBGH and Wal-Mart has removed products off their shelves that contain rBGH.

In addition to the direct negative effects of the hormone rBGH has on cows, there are many negative secondary effects. It is proven that: “Cows forced to produce unnaturally high quantities of milk can become malnourished because they lose more nutrients through their milk than they ingest in their feed, and are therefore more susceptible to disease.” (Hansen, 1997) Cows that are put under the large amounts of stress they are exposed to in the factory farming environment have significantly shorter life spans and are exposed to different harmful procedures such as long periods of time in artificial lighting, selective breeding and eating vast amounts of grain rather than grass. (Sustainable Table, 1998)

Overall, the common usage of synthetics and growth hormones in farm animals has numerous negative effects on animals. As I’ve explained, the most common hormone is rBGH and the usage of it is extremely controversial due to the common knowledge of the hormone’s health risks to both animals and humans.

Negative Effects on Humans

For many years, there has been an increasing controversy on the use of growth hormones on livestock. Farmers use natural and synthetic hormones in order to help progress the growth of their farm animals, particularly cows and sheep. With motives to help the progression of milk produce and meat products, farmers give certain hormones to the animals to speed up the process. Growth hormones not only hurt the animals that are being used but they also hurt the humans that consume the products from those farm animals (“EU).

Natural and Synthetic Growth Hormones that Cause Negative Effects to Humans

Relatively recent studies have shown the negative effects that these growth hormones have on humans. “The use of 6 natural and artificial growth hormones in beef production poses a potential risk to human health” (“Artificial). The hormones that are used are both natural and artificial. The three that are naturally occurring are: Oestradiol, Progesterone and Testosterone. The synthetic ones are: Zeranol, Trenbolone and Melengestrol.

Oestradiol, Progesterone and Testosterone all come from the protein hormone, Somatotropin, which is “produced in the pituitary gland of animals” (“rbGH). “Milk from rBGH-treated cows contains higher levels of IGF-1 (Insulin Growth Factor-1). Humans also naturally have IGF-1, and increased levels in humans have been linked to colon and breast cancer” (“rbGH).

The consumers that are impacted the most by these hormones are “children, pregnant women and the unborn” (“Artificial). Some of the residue from the growth hormones in beef has been recorded as being the reason why girls on the brink of puberty are at a greater risk of developing breast or other various types of cancer if they consume this meat (“Artificial).

Consumer Concerns

According to a Cornell University Fact Sheet on the concerns that humans have regarding growth hormones, “synthetic steroid hormones used a pharmaceutical drugs, have been found to affect cancer risk” (“Consumer). In the 1960s, a synthetic estrogen drug, diethylstilbestrol (DES), was used for a while until it was found to have caused vaginal cancer in the daughters of women who were treated with this drug (“Consumer). Once reports proved that DES was the cause for these issues, it was withdrawn from use in the United States. The use of growth hormones has been proven to be an increasing risk to all meat and dairy consumers.
When scientists first discovered that by injecting the material from bovine pituitary glands in cows caused an increase in the production of milk, the possibility of producing large quantities of dairy became inevitable. There wasn’t enough technology in the 1930s to find out the effects that this drug and its residue in meat and dairy products would have on all consumers. Therefore, farmers saw this as a huge opportunity. Even after the Food and Drug Administration (FDA) approved the recombinant bovine growth hormone (rbGH) in 1993, no side effects were brought to attention (“Consumer).

According to the Cornell University Fact Sheet, as of June 2000, scientists still don’t have a known method to accurately detect the level of hormones that are still in meat or dairy products that have been injected with rbGH. Therefore, there’s no set evidence to make a direct connection with the use of these growth hormones being the cause of breast cancer (“Consumer).

Some people tended to believe that the use of steroid hormones affected the age of puberty for girls. Reports have noticed the association and have recorded that “early puberty in girls has been found to be associated with a higher risk for breast cancer” (“Consumer).
Overall, the use of growth hormones has many negative effects on humans. Various types of cancer have been found with the use of these hormones, making them highly dangerous for human consumption. Most of the effects haven’t been directly connected, however with the increasing level of technology, hopefully scientists will uncover more evidence to make our food intake from farm animals safer and healthier.

Negative Effects on Our Environment

Most people worry about the effects growth hormones and synthetics used in animals have on humans and animals, they should realize the negative effect it has on our environment also. While we continue to consume dairy and meat products that are American made, there are countries that have banned the sale of our products. The reasons for these bans range from health concerns of consumers, animals, and the environment to the impact that it’ll have on their economy. There also lies the potential of genetic pollution which will lead to hybrid plants, animals, and insects.

Countries That Ban Meat and Dairy Products Produced From Animals That Were Given Synthetics And/Or Growth Hormones

The fear that the use of hormones and synthetics used in animals has led to the ban of American meats in Europe in 1985. The ban is the result of distrust that Europeans have for meats that are treated with hormones and synthetics, and because it was a threat to the livelihood of European farmers. Since there was so much meat being imported and having a lower cost, it led to a surplus of European grown meat. The US has threatened to dispute in the ban to the WTO, but British parliament voted to keep the ban, citing “consumer worries, questions of animal welfare, meat quality, and effects of hormones on the EU's beef and milk sectors. “ (Hanrahan).

Europe and Canada both have banned the sale of U. S. milk in their countries. This was done because the growth hormone rBGH that are used in cows have been linked to IGF-1 which is speculated to cause cancer. It is documented that, “a 1990 study by Monsanto, the leading maker of rBGH, explicitly revealed statistically significant evidence of growth promoting effects. Feeding relatively low doses of IGF-1 to mature rats for only two weeks resulted in statistically significant and biologically highly significant systemic effects: increased body weight; increased liver weight; increased bone length; and decreased epiphyseal width” (“Milk”). Even with these results the FDA failed to conduct a long term and refuses to require rBGH products to be labeled. This allows people who are not familiar with the growth hormones in milk, and the potential dangers they have, to continue to consume the milk without ever knowing. A majority of milk consumers are children who enjoy milk with cookies, cereal, etc. The American government program WIC even pays for families to get milk (amongst other items) so that children will grow healthy. If IGF-1 is actually linked to rBGH and it causes cancer, children will eventually get cancer in their life, which will continue to raise the price of healthcare in the future.

Threat to Our Ecosystem

A major concern of hormones and synthetics in animals is that the manure they produce is entered into our ecosystem and causes a lot of damage. Farmers store manure in tanks until it is turned into fertilizer. Since the manure is liquefied, it can easily leak out or seep out because of rain. Contaminates that manure contain can escape into nearby bodies of water and soil. It has been documented that, “excess nutrients from manure spills can cause large algae blooms in rivers and lakes that deplete oxygen in the water and kill fish. In 2005, a manure lagoon in Lowville, N.Y., spilled several million gallons into the Black River, killing some 250,000 fish. According to the Environmental Protection Agency (EPA), hog, chicken and cattle waste has polluted 35,000 miles of rivers in 22 states and contaminated groundwater in 17 states” (Weeks).This has led to environmental organizations pressuring the Environmental Protection Agency enforce regulations set such as the Clean Water Act, that ensures people from dumping pollutants into water.

It is also concern that, “conventional U.S. farmers annually use about 800 million pounds of synthetic pesticides, herbicides and insecticides. Farm runoff containing such chemicals is blamed for much of America's river and groundwater pollution, as well as lake fishkills. Some experts also fear that insects and other pests are becoming resistant to many commonly used pesticides and herbicides, some of which stay in the environment for years” (Koch). This can lead to what is referred to as “genetic pollution”. Genetic pollution occurs when “genetic information is transferred to the organisms where it is not needed or where this information never existed before” (Adnan). It is stated that, “critics say scientists do not fully understand the impact these genetic alterations will have on the nutritional quality or toxicity of foods. They fear that as a result of genetic manipulations, allergy-producing proteins may spread more widely through the food supply. They also fear that the technology has the power to create unintended ecological disaster in the form of rampant weeds, voracious, oversized fish and rapidly evolving plant viruses”(Philips, 1994). Insects and other pests that are resistant to pesticides and herbicides will mate with insects and pests that weren’t and this will lead to genetic changes in their species. Alterations to genetics can cause a ripple effect in our ecosystem that cannot be assessed now because we will not be able to see its full effect.


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