Jamie's Policy Paper

Incentive for Hog Farmers to Use Non-Antibiotic Feed

Just like humans, domestic animals are susceptible to bacterial diseases and infections. In many cases, humans and the domestic animals that they eat are susceptible to the same bacterial diseases and aided by structurally similar, if not the same antibiotics to combat these diseases. As such, resistances developed by bacteria among humans can be transferred to domestic animals and antibiotic resistances developed by bacteria affecting animals can be transferred to those among humans1. This cross-selection to/from humans is even truer for swine than for bovine and poultry due to the closer evolutionary relationship of humans to pigs. Unlike humans however, swine, like other domestic animals, are customarily given feed containing sub-therapeutic levels of antibiotics to promote growth2. In so doing, antibiotic resistant bacteria are selected for and become increasingly more prominent.
As in other vertebrates, hogs have a plethora of microflora in their gastrointestinal tract. The majority of these are gram-positive bacteria that provide numerous benefits to their host. These benefits are not without cost however. These commensal bacteria not only compete with the host for nutrients, but many also secrete toxins and stimulate a continual immune response, all three of which combine to inhibit the growth of the animal3. Orally ingested growth promoting antibiotics work primarily by reducing the bacteria in the gastrointestinal tract of vertebrate animals. This induces several means of increasing production, namely, preventing minor infections, reduction of competition for nutrients, decreasing the number of growth-repressing microbes, and increased absorption of nutrients through intestinal walls that are thinner since they do not have to constantly fight bacteria4.
While the benefits of using antibiotic growth promoters in hog feed are undeniable, so are the negative effects. In the United States, there are approximately five to one more domestic food animals than people. The amount of sub-therapeutic levels of antibiotics used in livestock in the U.S. is four to five times greater than the amount used to treat actual diseases in animals2. These antibiotics are not only selecting for bacteria in the gastrointestinal tract of these animals, but also enter the proteins and fats that we consume from them and in surrounding ground and water systems1. Because pigs are more similar to humans than other livestock animals, concerns of transferred resistance are even more critical.
To encourage swine farmers in the United States to use feed that does not contain antibiotics, it its proposed that Congress pass a 2.5% tax on products made with pigs given feed containing antimicrobials. The revenue from this tax will then be used to give an equivalent subsidy to those hog farmers who stop using feed with antibiotics to help balance out the costs of eliminating these substances. The tax would only apply to antibiotics used in food, as defined by Federal Food, Drug, and Cosmetic Act to be "articles used for food or drink for man or other animals" in sub-therapeutic levels in order to enhance growth and prevent infection. It does not apply to antibiotics prescribed by a veterinarian as a means of treatment and halting the spread of pathogens5. Nor does it apply to alternative growth promoters such as diet acidification, oligosaccharides, enzymes, herbs, minerals, probiotics, yeasts, and non-starch polysaccharides6. Since the use of antibiotic feed is already monitored by the Center for Veterinary Medicine, establishing this policy would have little to no cost.
Opponents may contest that reducing antibiotic growth promoters in hog farming will result in a significant loss of revenue for farmers who are already hard pressed to turn a profit. While this is a valid argument, the removal of antibiotic growth promoters in recently weaned pigs in Denmark was linked to a seven grams per day weight decrease and a .8% increase in mortality, the subsidy is in place to alleviate these costs and the tax help to balance out the market3. Depending on the market’s reaction to this policy, the income generated by the tax may not be enough to compensate those farmers who chose not to use antibiotic growth promoters. Such a case is not likely to occur right away, as many farmers will be reluctant to relinquish a practice that has been in place for over fifty years. Instead, there will likely be a gradual increase in the number of swine farmers that switch to non-antibiotic feed until the market reaches equilibrium, and ideally, to the point in which the majority of farmers are using non-antibiotic feed and the policy will become obsolete. By the time this occurs, however, feed producers will have adapted to meet the demands of the farmers by incorporating non-antibiotic growth promoting alternatives that are not affected by this policy.

1. Salyers, A. & Whitt, D. (2005). Revenge of the Microbes: How Bacterial Resistance is Undermining eh Antibiotic Miracle.
2. Levy, S. (1992). The Antibiotic Paradox: How Miracle Drugs Are Destroying the Miracle.
3. Dibner, J. & Richards, J. (2005). Antibiotic Growth Promoters in Agriculture: History and Mode of Action. Poultry Science Vol. 84, pp. 634-643. Retrieved Sept. 29, 2008. http://ps.fass.org/cgi/reprint/84/4/634
4. Gaskins, H., Collier, C., & Anderson, D. (2002). Antibiotics as Growth Promotants: Mode of Action. Animal Biotechnology Vol. 13, No. 1, pp. 29-42. Retrieved Sept. 29, 2008. http://ps.fass.org/cgi/reprint/84/4/634
5. Center for Veterinary Medicine. (2005). Animal Food (Feed) Regulation. U.S. Food and Drug Administration. U.S. Department of Health and Human Services. Retrieved Sept. 29, 2008. http://www.fda.gov/default.htm
6. Close, W. (2000). Producing Pigs without Antibiotic Growth Promoters. Advances in Pork Production Vol. 11, pp. 47-56. Retrieved Oct. 5, 2008. http://www.banffpork.ca/proc/2000pdf/Chap06-Close.pdf

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License