Executive Summary

Report

Feedlot Dust
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Koch
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Pilgrims Pride
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Smith Farms
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Sustainable Livestock
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Antibiotic Resistance
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Vertical Integration
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Natural Meat
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Organic Meat
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Recommendations  

There is growing concern over the consequences of over-use of antibiotics in livestock operations. Persistent use of antibiotics leads to the development of resistance in bacterial populations. Once a particular type of bacteria has developed resistance to an antibiotic, that antibiotic can no longer be used to combat the infectious organism.

In livestock industries, farm operators not only treat their animals with antibiotics for disease, but they also add antibiotics to the feed to promote growth. This long-term overuse of antibiotics in livestock production is now contributing to the development of resistant pathogens. This poses a problem for managing animal health, and it also may impact human health-antibiotic resistance can be passed between different types of bacteria and may therefore create resistance to antibiotics that humans depend on.

The US produces approximately 50 million pounds of antibiotics each year and 40% of that is given to animals, usually as a feed additive to promote growth. (1) More and more evidence shows, however, that infectious bacteria are quickly developing resistance to even the newest, most powerful antibiotics. Researchers have published disturbing reports that antibiotic resistance in Salmonella and Campylobacter, two human pathogens, is on the rise (2) and evidence is mounting that these resistant bacteria can be passed from chickens and pigs to humans through the food chain. (3) This poses a great health risk to the human population because it makes it easier for humans to become infected with resistant pathogens for which there are few effective treatment options.

It takes years to develop, test and gain approval for new antibiotic drugs. So while pharmaceutical companies are slowly developing potent new classes of antibiotics, resistance is developing at a rate faster than the drug companies can develop replacements. For example, within the last few years there has been an emergence of bacteria resistant to vancomycin-a last defense drug for some illnesses, including deadly blood infections and pneumonia caused by Staphylococcus bacteria (4) -and there is evidence that resistant bacteria may have been passed to humans in the meat products from livestock who were fed a similar antibiotic for growth purposes. (5) Likewise, a rise in antibiotic-resistant Campylobacter infections in humans has occurred in conjunction with the increased use of new classes of antibiotics such as the fluoroquinolones in animal production. (6)

As early as 1969, policy makers in other countries were calling for an end to the use of certain antibiotics as growth promoters in livestock. (7) In 1997, the World Health Organization issued a report re-emphasizing those recommendations, (8) yet livestock regulatory agencies failed to respond. In January 1999 the US Food and Drug Administration (FDA) proposed a policy for addressing the growing concern over antibiotic use in food animals. (9) Unfortunately, the proposed framework was weak on two key points:

• It focused mainly on evaluating new drug approvals while ignoring the millions of pounds of approved antibiotics that are already used for livestock production on a regular basis.
  
• It did not sufficiently address the risk of antibiotic resistance.
  

The FDA proposed a category and ranking system for antibiotics based in part on each drug's relative importance in human medicine. The most important drugs are those which treat serious diseases in humans and for which there is no alternative cure-these are listed as "Category 1" antibiotics. However, the FDA's proposal would allow even some Category 1 antibiotics to be used in livestock as long as the level of resistance that develops does not exceed a given "threshold" level. (10) Many people fear that even a limited use of Class 1 antibiotics will increase the chance that bacteria will develop resistance. When that happens, it may be too late to preserve the effectiveness of these important life-saving drugs in human medicine.

As an alternative, the National Research Council has reported that adopting simple production changes such as lowering stocking densities (less overcrowding), controlling stress, and improving hygiene could reduce the need for antibiotics without affecting output. (11) And now a broad coalition of environmental, farm, and public health groups are endorsing a new bill introduced to the US Congress (H.R. 3266) which would limit the sub-therapeutic use of certain antibiotics in livestock. (12)

NOTES:

1 Grady, Denise, "A Move to Limit Antibiotic Use in Animal Feed: Fewer Hardy Bacteria in People is U.S. Goal," New York Times, March 8, 1999, pp. A1, A13.

2 Grady (1999), p. A13 ; Endtz, Hubert Ph., Gijs J. Ruijs, et al., "Quinolone Resistance in Campylobacter Isolated from Man and Poultry Following the Introduction of Fluroquinolones in Veterinary Medicine," Journal of Antimicrobial Chemotherapy, Vol. 27 (1991), pp. 199, 200; Seyfarth, Anne Mette, et al., "Antimicrobial Resistance in Salmonella enterica subsp. enterica serovar typhimurium from humans and production animals," Journal of Antimicrobial Chemotherapy, Vol. 40 (1997), p. 67.

3 Seyfarth et al. (1997), p. 74; Endtz et al. (1991), pp. 199, 206; Hawkes, Nigel, "Antibiotics in Cattle Feed Linked to Superbug," The Times of London, March 24, 1998, Internet source: http://www.enviroweb.org/hecweb/archive/farm/antibiotics.htm.

4 Smith, Theresa L., et al., "Emergence of Vancomycin Resistance in Staphylococcus aureus," The New England Journal of Medicine, Vol. 340, No. 7 (February 18, 1999), pp. 493-501.; Levy, Stuart B., "The Challenge of Antibiotic Resistance," Scientific American (March 1998), pp. 46-53.

5 Bates, Janice, et al., "Farm Animals as a Putative Reservoir for Vancomycin-resistant Enterococcal Infection in Man," Journal of Antimicrobial Chemotherapy, Vol. 34 (1994), pp. 507, 510; Wegener, Henrik Caspar, et al., "Isolation of Vancomycin Resistant Enterococcus faecium from Food," International Journal of Food Microbiology, Vol. 35 (1997), pp. 58, 64; Bager, F., et al., "Avoparcin Used as a Growth Promoter is Associated with the Occurrence of Vancomycin-resistant Enterococcus faecium on Danish Poultry and Pig Farms," Preventive Veterinary Medicine, Vol. 31 (1997), pp. 95, 109-111.

6 Endtz et al. (1991), p. 199.

7 Witte, Wolfgang, "Medical Consequences of Antibiotic Use in Agriculture," Science 279 (February 13, 1998), p. 996.

8 World Health Organization, The Medical Impact of the Use of Antimicrobials in Food Animals: Report of a WHO Meeting (WHO: Berlin, Germany, October 13-17, 1997), p. 1.

9 Federal Register, Vol. 64, No. 3 (January 6, 1999).

10 A Proposed Framework for Evaluating and Assuring the Human Safety of the Microbial Effects of Antimicrobial New Animal Drugs Intended for Use in Food Producing Animal (FDA Discussion Paper, January 6, 1999), pp. 8-9, 14-17.

11 National Research Council, "Approaches to Minimizing Antibiotic Use in Food-animal Production," in: The Use of Drugs in Food Animals: Benefits and Risks (National Academy Press: Washington, D.C., 1999), pp. 189-193.

12 H.R. 3266 (Rep. Sherrod Brown), The Preservation of Essential Antibiotics for Human Diseases Act of 1999.