Injection Of Hormones In Food Animals Biology Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

Injection of hormones in food animals has been introduced to food animal production since as early as 1930's. Bovine Somatotropin (BST) or also known as Bovine Growth Hormones (BGH) is a naturally secreted by the pituitary gland of cows where the traces were found in milk secreted from injected animals. Few countries have authorized the use of growth hormones while others have banned their use. [1] However, due to high demand on foods, more and more live stocks are being slaughter and forced to sacrifice their meats just to satisfy men's greediness. In this case, the amount of livestock required will also increase as it is highly demanded in the meat and dairy industry. The high in percentage uses of the growth hormones for calves should not be approved and focus of the safety or side. Highly usage of growth hormones in food animals may cause the animal itself which might transfer to human and face a higher risk of diseases related to injection of hormones in food animal. Hormones are used in food animals to increase the production and mainly for humanity livestock, but do the foods we eat daily are safe to be eaten and what are the effects to human health? The purpose of this research of study is to investigate the effects of uses due to exposure of injected food animal.



What is injection of hormones? Injection of hormones is a very profitable for the farmers as they help the animals to gain weight as well as increase the amount of milk. Injecting hormones in cattle is very common to farmers in meat and dairy industry where the hormones are naturally secreted from the pituitary gland of cows. Even though, this can be really harmful for human, animals and environment. Basically, hormones are very essential for the proper functioning of the various body organs of the humans, as well as other animals but imbalance of a single hormone can create a lot of problems. Hormones are certain kind of chemicals that are naturally present in the human body. They are actually produced in a very small amount in the various hormone producing organs, but their role is very significant in various body functions, including reproduction as well as development and growth of various body parts. [2]

BST is discovered in early 1930's where it was found that rats in the growth phase when injected with a crude rat pituitary extract underwent increased the growth rate. Then, hormone development research is started in the 1950's and was discovered that certain types of human dwarfism were due to an inadequate pituitary production of somatotropin. However, clinical trials involving the injection of these patients with BST demonstrated that BST was not biologically active in humans. BST is produced naturally by all cows and has direct and indirect effects in coordinating the metabolism of various body organs and tissues to the requirements of milk production. [3]


Since 1940's, steroid hormones are usually released into the animal from a pellet, that is put under the skin of the ear. The ears of the animals are thrown away at slaughter. Improper use of pellet implants in other parts of the animal can result in higher levels of hormone residues to remain in the edible meat. Each pellet consists of growth-promoting hormone that is released slowly into the blood and then carried to tissues. Diethylstilbestrol (DES) was the first growth-promoting compounds. It was taken off the market many years ago because of its potential danger for consumers. This is because it will increase the chance of cancers and infertility. Federal regulations prohibit their use in this manner. Melengestrol Acetate is also available in a form that can be added to animal feed. Dairy cattle may be injected under the skin with bovine growth hormone (rbGH). This hormone is available in packages of single dose injections to reduce chances of accidental overdose. [3]

Since the early 1970s, hormones have been used in the production of beefs and milk in the US where two third of cattle raised in US is treated with hormones. Although growing numbers of consumers and scientists have expressed concerns about potential human health, the United States Drug Administration (USDA) and Food and Drug Administration (FDA) have approved the use of hormone growth promotants (HGPs) in the cultivation of beef cattle and other hormone is used to increase the production of milk. [4]



BST which interacts with other hormones in cows' bodies to control the amount of milk they produce. Scientists working for Monsanto, the agricultural giant, developed a genetically-engineered synthetic version of the hormone called rBGH that increased milk production by 10% to 25%. Approved by the FDA in 1993, it was offered to interested farmers the next year. By 2008, a third of American dairy cows were being injected with rBGH.


The US cattle industry started using hormones to enhance beef production in 1956. They used DES, which had been approved for use in beef cattle in 1954. In the 1970s FDA approved six hormone growth promotants (HGPs). These included three naturally occurring hormones - Oestradiol, Progesterone and Testosterone - and three synthetically prepared hormones - Zeranol, Trenbolone, and Melengestrol. These helps to improve meat quality by increasing the development of lean meat and decreasing fat content, increase feed efficiency thereby allowing more growth with less feed, reduce costs for producers thereby reducing the price of meat and meat products for consumers.[1]


In 2004, the US veal industry was found guilty of injecting 90% of its calves with growth hormones. These hormones included all six HGPs approved for use in adult cattle only, bringing into focus the safety or side effects of injecting calves with hormones intended for heifers and steers over 700 lbs, a fact that has never been evaluated. It is suspected that these hormones may be metabolized differently in the young calf's body which could lead to greater amounts of hormones consumed by people who eat veal.


In the 1980's, it became possible to produce large quantities of pure BGH by using recombinant DNA technology. In 1993, the FDA approved the rbGH for use in dairy cattle. Recent estimates by the manufacturer of this hormone indicate that 30% of the cows in the US may be treated with rbGH. The female sex hormone Oestrogen was also shown to affect growth rates in cattle and poultry in the 1930's. Once the chemistry of Oestrogen was understood, it became possible to make the hormone synthetically in large amounts. Synthetic Oestrogens started being used to increase the size of cattle and chickens in the early 1950's. [5]

The use of growth hormones increase milk production is approved for use in the United States. However, it is not for sale in Canada or the European Union (EU) approved. The use of growth hormones in cattle is approved in US and Canada but banned in EU. Now, there are total of 24 countries which have actually given approval for use of BST, namely Algeria, Brazil, Bulgaria, Columbia, Costa Rica, Czech Republic, Honduras, Hungary, Jamaica, Kenya, Korea, Malaysia, Mexico, Namibia, Pakistan, Peru, Romania, Russia, Slovakia, South Africa, Turkey, UAE, Ukraine and Zimbabwe. [3]



The increasing amount of antibiotic residues was observed in cow's milk following the use of rbGH. At the same time, while rbGH is started to be used, some of the major dairy states in US switched over to a improved method to test for antibiotic residues. It is difficult to determine whether the increasing amount of antibiotic residues in milk was due to increased use, or better testing methods. Due to the increasing of milking, hormone-treated cows may become more prone to infection of mastitis. It causes more antibiotics to be used to treat the cows, and thus causing more antibiotics to remain in the milk. For people over the long term which are frequently exposed to antibiotic residues through milk or dairy products, their health need to be concerned. In a normal body, there are bacteria that live in the gut and mouth which are used to help in the digestion of food.  Since the immune system keeps them in check, normally these bacteria do not cause disease. However, if the immune system is weak, these bacteria can attack the tissues and cause infection to be occurred. Moreover, the bacteria that come across the antibiotics, can develop ways to survive the antibiotics and become "antibiotic resistant." In cases of infection and illness, it then becomes more difficult to control such resistant bacteria with the available antibiotics.

"Cows are treated with hormone in the concern of increasing milk production. This cow may become prone to infection of udders called mastitis. This result more antibiotic is being used to treat them, in which leading the milk contains more residues of antibiotics. If a normal body, frequent exposure to these antibiotic residues through milk or dairy products causes antibiotic resistant. Bacteria in human's body tends develops ways to survive the antibiotics as antibiotics enter the body. In the cases of infection or illness, it becomes more difficult to control such resistant bacteria with the available antibiotics."

(Renu Gandhi, Ph.D. BCERF Research Associate and Suzanne M. Snedeker, Ph.D,2003)

"Based on the EU legislation, for any action on the growth promotion in farm animal by using substances having hormones was prohibited in 1981.The prohibition was applied to the Member States. The first banned was during 1980s regarding the import of hormones raised beef. However based on the US legislation, the FDA permits the use of hormones and synthetic hormones. Recombinant bovine growth hormone (bovine somatotropin) is permitted in USA for dairy cattle only. (Linda A. Mooney David Knox and Caroline Schacht) But countries like Japan, Europe, Canada, Australia and New Zealand banned this milk."

(Richard Lawley, Laurie Curtis, Judy Davis, 2008)

"With the modern method of raising animal, there is significant concern on the health safety in the industrialized world, where about 30 percent of the population suffers from food-borne disease each year. (Dr Pandula Siribaddana, 2010) Defined that intake of food is unhygience due to presence of infective pathogenic organism."

(World Health Organization, 2007)


The use of hormonal growth promoters in beef cattle is an issue which has sparked much debate around the world. They are approved for use in Canada and the US. However, the use of hormonal growth promoters is banned in the EU. Exposure to growth hormones in beef could be putting Americans at risk for infertility. Estrogenic chemicals injected like DDE can be associated to breast cancer. The assumption was based on the study conducted by Mt. Sinai Medical Center in New York to 58 breast cancer patients who were found to have high levels of DDE to their blood serum. The same chemical was also found that interfaces with the mother's natural ability to lactate. A recent study found that women who routinely ate beef were far more likely to give birth to boys who grow up to have lower-than-normal sperm counts. Hormone residues in beef have been implicated in the early onset of puberty in girls, which could put them at greater risk of developing breast and other forms of cancer. [1]

The National Academy of Sciences documented cases of children who are susceptible with the toxic effects of chemicals in growth hormone. Children who consumed milk fat and breast-fed were 40 times vulnerable to various diseases. Case in 1985, 117 children born to women who were ingested contaminated oil were examined which exposed children had abnormalities of the lungs, gums, nails, teeth and skin. Another effects were their less weight and height, even boy ranges from 11-14 had shorter penises. [5]


There has been, and continues to be, controversy about the use of BST, originating with opponents of its approval before and after its approval by the FDA in the USA in February 1994, but spilling over into the rest of the world and especially Europe and Canada. Expressed concerns have centred on four main aspects, human health, animal health and welfare, labelling and socio-economic aspects. Objective assessment has been clouded by media-amplified fears generated by organisations and individuals opposed to any use of modern biotechnology, and confusion caused by trade-motivated use of selectively emphasised evidence. [3]

In February 1999, FDA's Center for Veterinary Medicine (CVM) issued an update, in which it reported that it had conducted a review of the human safety aspects of the use of rbST, stimulated by the product's review for approval in Canada. The CVM review upheld the FDA's original conclusion that milk from cows treated with rbST is safe for human consumption.

Endocrine-disruptor expert, Ana Soto, concluded that hormone levels in water run-off found in one downstream study "would be sufficient to produce a significant effect on target cells" and her study's findings "point to the need to take steps to curtail environmental degradation caused by the release of these chemicals into bodies of water."


Injection of hormones in food animals did solve human food problem, however, the undeniable fact is the use of injection of hormone will cause long-term effect on human health. Hence, the use of injection hormone should be inspected consistently to prevent from misusing it. In addition, issues of injection of hormones in food animals should be concerned by everybody especially World Health Organization (WHO). Evidences of the implication to human health from scientists past researches have been shown. So, preventive ways should be taken in order to ensure human's health is always in a healthy state. Awareness campaign should be done to let the people to know more and have a better understanding about the food they are eating everyday. Furthermore, researches should also keep going on to find alternative ways to solve the difficulties faced globally.