Bovine Somatotropin Term Paper

Introduction

Each year farmers raise up to 36 million beef cattle. But did you know that farmers fatten up to 2/3rd of these cows with hormones (sciencenews.org). Our group did not, but when we heard this we knew that it would be an interesting and controversial topic to research further. None of us ever thought that when we were buying meat from the grocery store that it would be anything more than just meat. And as we looked further into the topic we were surprised to see that the same goes for milk, and that the use of growth hormones in cattle is becoming a growing trend and unavoidable.

These growth hormones are very similar to the steroids that people take. They are most commonly dispersed to the animals through their feed, but there is also a new way of dispersing the drugs. It is through a device that is placed in the cattle's ear, which periodically gives them a dose of the drug (sciencenews.org). These hormones are used to beef up the cattle so that farmers can get more meat but with fewer animals. They also do the same thing in dairy cows only the hormones make the cows produce more milk. "A typical dairy cow is expected to produce 5,000-6,000 litters of milk a year, but with selective breeding and concentrated feed practices, cows are able to produce ten times more milk" (dairyreporter.com).

Currently all of this has been approved by the FDA and is becoming a very common practice. The most common growth hormone BST has been in use since 1994 and was approved by the FDA in 1993. But although this is true, some feel that more needs to be done to further understand the effects it can have on people's health. This is especially true with the European Union (EU). "Since 1988, concerns about the potential health risks of drug residues have led the EU to ban importation of the meat of hormone-treated animals. The United States and Canada, which produce such meat, have vigorously fought the ban through both punitive tariffs on various imports form Europe and appeals to the World Trade Organization" (dairyreporter.com). This is the only nation to have completely banned the use of hormones in cattle. Elsewhere it is just heavily monitored. The US FDA regulates the medicated feed for cattle and other livestock. All feed mills have to be registered with the FAD and are subject to routine inspection (iabeef.org). There is also another division of the FDA called The Center for Veterinary Medicine (CVM), which regulates the manufacture and distribution of food additives, and drugs that will be given to animals. This includes animals from which human foods are derived (FDA.gov). Another law that helps regulate the use of hormones in cattle is the Animal Drug User Fee Act. This permits the FDA to "collect subsidies for the review of certain drug applications from sponsors, analogous to laws passed for the evaluation of other products the FDA regulates, ensuring the safety and effectiveness of drugs for animals and the safety of animals as foodstuffs" (FDA.gov). And the final thing used to further regulate the use of hormones is the National Antimicrobial Resistance Monitoring System-Enteric Bacteria (NARMS-EB). This is a system that was put in place to allow the FDA to monitor resistance to antimicrobials used in humans and food animals (iabeef.org). All of this seems like a very effective way of regulating the effects and use of hormones placed in cattle feed, but how do we the consumers know if the beef that we are eating has been enhanced with steroids? Well, the packaging on the meat will not directly say if the meat has bee enhanced, but it will tell you if it has not through phrases like 'natural,' 'organic,' and 'no antibiotics/ no hormones'. This is because the USDA requires that meat packages be labeled (grinningplanet.com).

Science

The most commonly used growth hormone used in cattle today is Bovine Somatotropin which is also known as POSILAC, bST, rbST, bGH, and rbGH. BST is used primarily in dairy cows and can greatly increase the amount of milk that a cow may produce. BST has been approved in the United States since February of 1994.

BST is present in all cows' milk and is naturally produced by all cows. Many people may think of bST as some type of steroid but it is not. BST is a protein hormone. The difference between a steroid and a protein hormone is that protein hormones are not biologically active if they are ingested orally. If ingested, most bST is destroyed by acids produced in the stomach, so there are no effects. Because of this, bST must be injected into a cow in order for it to take any effect.

BST allows for higher milk production in dairy cows. Basically bST promotes the production of the hormone IGF-1, which stimulates glands in cows' udders. Cows have a peak lactation period and after this period the amount of milk produced will go down. BST minimizes the rate of decline after this peak lactation.

There have been many studies done on the effects of bST. In a study done by R.J. Collier, the health of dairy cows treated with bST was determined. The results showed that milk production went up when cows were treated with bST. All reproductive processes were unaffected by bST. Instances of mastitis were unaffected by the use of bST also. The only negative thing that the study showed was that there was a slight increase in foot disorders. The conclusion of the study basically said that bST is adequate for safe use. Another study done by D. Hoeben studied the effect of bST during experimental mastitis (inflammation of breast or udder). The results of the study showed that treatment of bST was helpful. As in other studies, milk production increased. They also found that in the bST treated group, milk production was completely restored after three weeks of mastitis infection. After three weeks the control group production remained lower than pre-infection production. There were also more bacteria present in the milk of the control group. The study concluded that cows infected with mastitis recovered more quickly when treated with bST than in the control group.

Even with lack of evidence, use of bST is still a controversial subject. The increases in hormone IGF-1 is said to increase the risk of breast cancer and prostate cancer. The only problem with this is that there has been no scientific evidence to support this theory. There has been much speculation but not much research done on the risk of cancer from bST treated cows. Another controversy with bST is the increase of mastitis. I have talked to a couple dairy men and some of them say bST does affect the prevalence of mastitis and others say it has no affect. The reason for this controversy of mastitis