Food for Thought, Part I: Foodborne Illness and Factory Farming : Holistic Nursing Practice

Secondary Logo

Journal Logo


Food for Thought, Part I

Foodborne Illness and Factory Farming

Ross, Stephanie Maxine MH, HT, CNC

Author Information
Holistic Nursing Practice 24(3):p 169-173, May 2010. | DOI: 10.1097/HNP.0b013e3181dd4711
  • Free

We live in an era where the safety of the food that we eat, the water that we drink, and the air that we breathe are of major concern for our health and well-being. As individuals who are concerned with health issues, we need to become educated and proactive with the very basic elements that directly influence our health, which include foodborne illnesses, food irradiation, genetically modified foods, and the toxins that are found not only in our food but also in the water that we drink and the air that we breathe. This article is the first in a series of articles that will examine modern food production and how our food choices affect our health, the human food chain, and ultimately the world in which we live.


Since ancient times, farmers passed down priceless ancestral wisdom from parent to child, from generation to generation. A time-honored ancient contract sealed the agreement among those people who raised animals for meat, milk, and eggs to ensure that the basic needs of the animals under their care were satisfied. Traditional wisdom guided the farmer in how to provide the animals with environments that were harmonious, nutritive, and protective from predators and natural elements. If animals fell ill or suffered from lack of food, water, or protection, the farmer and his family suffered, as well as their animals. Both farmers and livestock ranchers prided themselves on being stewards of the animals they raised.

In the latter part of the 20th century, a dramatic change took place with the advent of intensive factory farming. The ancient contract of responsible stewardship, once honored by farmers for thousands of years, was replaced by intensive factory farming methods that exchanged ethical farming practice for increased economic profitability, at the expense of animal welfare and the increase in potential adverse health consequences to the general public.


Current scientific literature provides overwhelming evidence that the manner in which we treat our animals can result in deleterious public health implications.1 In fact, history has unequivocally shown that many of humanity's disease epidemics, including measles, influenza, and smallpox, have their origins from the domestication of farm animals.2–4 In addition, the emergence of more recent diseases such as SARS (severe acute respiratory syndrome), an acute respiratory illness caused by a coronavirus that infected more than 8000 people worldwide, has been directly linked to live animal markets.5 Mad cow disease or bovine spongiform encephalopathy (BSE) is a viral disease that causes fatal dementia in cows and a form of human dementia called Creutzfeldt-Jakob disease, which infect humans after eating the meat from BSE contaminated cows. Mad cow disease and the ensuing BSE epidemic were the creation of the factory farming biz and their unethical practice of feeding cows slaughterhouse waste (dead cow meat), cow's blood, and chicken manure.6 The origins of BSE and the subsequent BSE global epidemic have become the most widely acknowledged illustration of the indisputable link between the unconscionable cruelty and mistreatment of animals and the potential increased risk for adverse health effects worldwide.6,7

Yet, the most commonly diagnosed foodborne illness in the United States, and of central focus to this article, is the bacterial pathogen Salmonella, which is the leading cause of food-related death.8,9 The primary source of Salmonella infections in humans are eggs.10 Scientific research clearly indicates that intensively confining egg-laying hens into “battery cages,” which is analogous to stuffing several hens into a nonlegal sized filing drawer, rather than allowing them to live cage-free, results in a significant increase in the risk of Salmonella foodborne disease.11,12


The National Academy of Sciences' Institute of Medicine, in its landmark report, “Emerging Infections: Microbial Threats to Health in the United States,” clearly states that “the introduction of feedlots and large-scale poultry rearing and processing facilities has been implicated in the increasing incidence of human pathogens, such as Salmonella, in domestic animals....”13 Because Salmonella can infect the ovaries of hens, infected eggs can be laid prepackaged with the bacteria inside.14 The Centers for Disease Control and Prevention and the US Department of Agriculture estimate that infected eggs may cause approximately 180 000 cases of Salmonella infection in the United States per year, at an annual cost of billions.15,16 There are several “factory farming practices” that have contributed to the emergence of egg-borne Salmonella infection.

Battery cages

In the United States, battery-caged hens are presently confined to 5 to 10 hens per cage, which affords each hen a living space of less than an 8.5 in by 11 in single sheet of paper for a maximum 2-year occupancy, equivalent to their entire life span.17–19 Because of the stressful overcrowded conditions, the innate pecking order of chickens is obliterated, and as a result they become violent and at times peck each other to death. The factory farm industry's solution is a procedure called “debeaking,” which involves cutting off one-third of the beak of each chicken to prevent them from killing one another. Debeaking often leaves the chickens so mutilated that it interferes with their ability to eat, resulting in starvation.

Spent hen meal

According to the World Health Organization, “factors facilitating the spread of Salmonella are associated with the intensification of animal and poultry production. ...”20 These factors include the industry's selective breeding practices, forced starvation molting, and the “feeding of slaughterhouse waste to hens.”21,22 More explicitly, when the hens' egg production declines, they become candidates for “spent hen meal” or slaughterhouse feed, better translated, they are ground up and then fed to other hens.23 On a yearly basis, the United States produces the majority of the estimated 10 million tons of “animal protein concentrates” that is incorporated worldwide into animal farm feed, such as meat, blood, and bone meal, or more specifically, “trimmings that originate on the killing floor, inedible parts and organs, cleaned entrails, fetuses.”24–26

Interesting to note is that more than 50% of feed samples containing slaughterhouse waste tested by the FDA was contaminated with Salmonella, and innumerable accounts of human Salmonella infections have been specifically linked to the feeding of farm animals contaminated meat and bone meal.27–29 In addition, the Centers for Disease Control and Prevention has estimated that more than 1 000 000 000 incidents of Salmonella poisoning in the United States can be directly connected to feed containing animal by-products.30

Forced starvation molting

Forced starvation molting is a process that has been employed by the factory farming industry to stimulate waning egg production in hens. The practice involves withdraw of feed for 10 to 15 days or until the hens lose up to 35% of their body weight; this shocks the hen into losing its feathers and, for those that survive, a new egg-laying cycle begins.31 As a result of the extreme stress, the immune system of the hen is often compromised, increasing the likelihood for Salmonella infection. It is well known that forced starvation molting increases the risk of hens laying Salmonella-infected eggs.32

Physiological stress

According to the International Journal of Medical Microbiology, research clearly demonstrates that stress hormones can increase Salmonella colonization and systemic spread of infection in chickens.33 It has been shown that the stress hormone noradrenaline has the ability to stimulate the growth rate of Salmonella exponentially, while at the same time corticosteroid hormones can reduce immune function.34,35

The factory farm industry's effortless attempt to counteract the stressful, intensely overcrowded, and unhygienic conditions, is to feed millions of pounds of antibiotics to farm animals every year.36 The practice of lacing animal feed with antibiotics has been condemned by the American Medical Association, the American Public Health Association, the Infectious Disease Society of America, and the American Academy of Pediatrics; yet, the factory farming industry arrogantly continues in their irresponsible and dangerous practice.37


Battery cages, cage-free, organic, free range

The European Union initiated an extensive study, to determine the public health implications of phasing out the use of conventional battery cages.38 This study compared the Salmonella infection risk between different laying hen housing systems, namely battery cages, cage-free (barn-raised), organic production, and free range (pasturing). The study revealed that the incidence of Salmonella Enteritidis contamination was 43% less in cage-free egg production, 95% less in organic egg production, and 98% less in free-range systems than in battery-caged egg production. The study results of Salmonella Typhimurium, the most common type of Salmonella poisoning in the United States, indicate that there was 77% less Salmonella infection among cage-free hens and 93% less Salmonella contamination in organic and free-range hens than in battery-caged production. The European Food Safety Authority concluded, “without exception battery-caged hens are more likely to be contaminated with Salmonella.”

The European Union, including all 27 countries, has banned the use of battery cages, and as a result has witnessed a significant decline in Salmonella infections. Unfortunately, the efforts to control Salmonella in the United States is shamefully inadequate in comparison with the European Union and other countries that have eliminated the health hazard.39 According to a former US Department of Health and Human Services Senior Nutrition Policy Advisor, “major food industries oppose pathogen-control measures by every means at their disposal.”40

Apparently, the factory farming industry is devoid of conscience, for profitability seems to be their motto, and supersedes ethical farming practice and public health safety.


Since ancient times, traditional wisdom guided the farmer in how to provide his animals with environments that were harmonious, nutritive, and protective from predators and natural elements. Today, intensive factory farming methods have exchanged ethical farming practice for increased economic profitability, at the expense of animal welfare and the increased potential adverse health consequences to the general public. Current scientific research validates ancestral farming wisdom and provides overwhelming evidence that the manner in which we treat our animals can result in deleterious public health implications.

The most commonly diagnosed foodborne illness in the United States is the bacterial pathogen Salmonella, which is the leading cause of food-related death. The primary source of Salmonella infection in humans is eggs. Scientific research clearly indicates that intensively confining egg-laying hens into “battery cages” rather than allowing them to live “cage-free” results in a significant increase in the risk of Salmonella foodborne disease. To reduce the incidence of Salmonella foodborne illness, acquired through the consumption of eggs, studies suggest purchasing eggs from cage-free, organic egg, or free-range sources.



Harvest for Hope: A Guide to Mindful Eating by Jane Goodall

The Food Revolution: How Your Diet Can Save Your Life and Our World by John Robbins

Omnivore's Dilemma by Michael Pollan

Fast Food Nation by Eric Schlosser

Diet for a Small Planet by Anna and Francis Moore Lappè


Proposition 2, “Prevention of Farm Animal Cruelty Act,”

Web site

Mother Earth News,

Meet the Free Range Eggs, a comparison chart that shows the average nutrient content of cage-free and free-range raised hens, compared to the nutrient content of battery-caged hens.

Cage-free egg source

Nature's Yoke, (store locator)

Lancaster, Pennsylvania.

Look to purchase “Organic and All-Natural Eggs from Cage Free Hens,” raised on small, sustainable farms like Nature's Yoke.

(A special thank you to George Weaver III at Nature's Yoke for his commitment to produce quality eggs by utilizing careful farming management and hen care.)

Nonprofit groups (not inclusive)

Dedicated to educating the public about factory farming.


1. Wolfe ND, Dunavan CP, Diamond J. Origins of major human infectious diseases. Nature. 2007;447(7142):279–283.
2. Guber C, Hue S, Kellam P, Smith GL. Poxvirus genomes: a phylogenetic analysis. J Gen Virol. 2004;85:105–107.
3. Shortridge KF. Severe acute respiratory syndrome and influenza: virus incursions from southern China. Am J Respir Crit Care Med. 2003;168(12):1416–1420.
4. Weiss RA. The Leeuwenhoek lecture. Animal origins of human infectious disease. Philos Trans R Soc Lond B Biol Sci. 2001;356(1410):957–977.
5. Kan B, Wang M, Jing H, et al. Molecular evolution analysis and geographic investigation of severe acute respiratory syndrome coronavirus-like virus in palm civets at an animal market and on farms. J Virol. 2005;79(18):1192–1900.
6. Wilesmith JW, Ryan JB, Atkinson MJ. Bovine spongiform encephalopathy: epidemiological studies on the origin. Vet Rec. 1991;128(9):199–203.
7. US Department of Agriculture Food Safety and Inspection Service. California firm recalls beef products derived from non-ambulatory cattle without the benefits of proper inspection. Published 2008. Accessed February 15, 2010.
8. Chittick P, Sulka A, Tauxe RV, Fry AM. A summary of national reports of foodborne outbreaks of Salmonella Heidelberg infections in the United States: clues for disease prevention. J Food Prot. 2006;69(5):1150–1153.
9. Mead PS, Slutsker L, Dietz V. Food-related illness and death in the United States. Emerg Infect Dis. 1999;5(5):607–625.
10. Patrick ME, Adock PM, Gomez TM, et al. Salmonella enteritidis, United States, 1985–1999. Emerg Infect Dis. 2004;10(1):1–7.
11. Molbak K, Neimann J. Risk factors for sporadic infection with Salmonella enteritidis, Denmark, 1997–1999. Am J Epidemiol. 2002;156(7):654–661.
12. World Health Organization and the Food and Agriculture Organization of the United Nations. Risk assessments of Salmonella in eggs and broiler chickens. Microbiological risk assessment series 2. Published 2002. Accessed February 15, 2010.
13. Lederberg J, Shope RE, Oaks SC. Emerging Infections: Microbial Threats To Health in the United States. Washington, DC: The National Academies Press; 1992.
14. Gast RK, Beard CW. Production of Salmonella enteritidis-contaminated eggs by experimentally infected hens. Avian Dis. 1990;34(2):438–446.
15. Schroeder CM, Naugle AL, Schlosser WD, et al. Estimate of illness from Salmonella enteritidis in eggs, United States, 2000. Emerg Infect Dis. 2005;11(1):113–115.
16. Bryan FL, Doyle MP. Health risks and consequences of Salmonella and Campylobaeter jejuni in raw poultry. J Food Prot. 1995;58(3):326–344.
17. Bell DD. Cage management for layers. In: Bell DD, Weaver WD, eds. Commercial Chicken Meat and Egg Production. Norwell, MA: Kluwer Academic Publishers; 2001:52–64.
18. United Egg Producers. United Egg Producers animal husbandry guidelines for U.S. egg laying flocks. 2008.
19. Bell DD, Weaver WD, eds. Commercial Chicken Meat and Egg Production. Norwell, MA: Kluwer Academic Publishers; 2002:1061.
20. World Health Organization. Technical paper: Main challenges in the control of zoonotic diseases in the Eastern Mediterranean Region. Agenda item 8(c). Regional Committee for the Eastern Mediterranean, 50th session. Published August 2003. Accessed February 15, 2010.
21. Hunter PR. Epizootics of Salmonella infection in poultry may be the result of modern selective breeding practices. Eur J Epidemiol. 1992;8(6):852–855.
22. Turnbull PCB. Food poisoning with special reference to Salmonella–its epidemiology, pathogenesis and control. Clin Gastroenterol. 1979;8(3):663–714.
23. Fritts CA, Kersey JH, Waldroup PW. Utilization of spent hen meal in diets for laying hens. Int J Poult Sci. 2002;1(4):82–84.
24. National Renders Association. U.S. production, consumption and export of rendered products for 1998–2003. 2005.
25. World Health Organization and the Office International des Epizooties. WHO consultation on public health and animal Transmissible Spongiform Encephalopathies: epidemiology, risk and research requirements. With the participation of the Office International des Epizooties. Geneva, Switzerland, 1–3 December 1999. Accessed February 15, 2010.
26. Ensminger ME, Oldfield JE, Heinermann WW. Feeds & Nutrition. Clovis, CA: The Ensminger Publishing Company; 1990.
27. Hirsch W, Sapiro-Hirsch R. The role of certain animal feeding stuffs especially bone meal, in the epidemiology of salmonellosis. Harefuah. 1958;54(3):57–59.
28. Knox WA, Galbraith NS, Lewis MJ, Hickie GC, Johnston HH. A milk-borne outbreak of food poisoning due to Salmonella heidelberg. J Hyg (Lond). 1963;61:175–185.
29. Pennington JH, Brooksbank NH, Poole PM, Seymour F. Salmonella virchow in a chicken-packing station and associated rearing units. Br Med J. 1968;4(5634):804–806.
30. Crump JA, Griffin PM, Angulo FJ. Bacterial contamination of animal feed and its relationship to human foodborne illness. Clin Infect Dis. 2002;35(7):859–865.
31. Webster AB. Behavior of white leghorn laying hens after withdrawal of feed. Poult Sci. 2000;79(2):192–200.
32. Holt PS, Porter RE. Microbiological and histopathological effects of an induced-molt fasting procedure on a Salmonella enteritidis infection in chickens. Avian Dis. 1992;36(3):610–618.
33. Methner U, Rabsch W, Reissbrodt R, Williams PH. Effect of norepinephrine on colonisation and systemic spread of Salmonella enterica in infected animals: role of catecholate siderophore precursors and degradation products. Int J Med Microbiol. 2008;298(5–6):429–439.
34. Bailey MT, Karaszewski JW, Lubach GR, Coe CL, Lyte M. In vivo adapation of attenuated Salmonella typhimurium results in increased growth upon exposure to norepinephrine. Physiol Behav. 1999;67(3):359–364.
35. Shini S, Kaiser P, Shini A, Bryden WL. Biological response of chickens (Gallus gallus domesticus) induced by corticosterone and a bacterial endotoxin. Comp Biochem Physiol B Biochem Mol Biol. 2008;149(2):324–333.
36. Office of Technology Assessment. Drugs in Livestock Feed. Volume 1: Technical Report. Washington, DC: US Government Printing Office; 1979. Accessed February 15, 2010.
37. Keep Antibiotics Working. Kennedy, Snowe & Slaughter introduce AMA-backed bill to cut antibiotic resistance linked to misuse of antibiotics in animal agriculture. Published 2007. Accessed February 15, 2010.
38. European Food Safety Authority. Report of the Task Force on Zoonoses Data Collection on the Analysis of the baseline study on the prevalence of Salmonella in holdings of laying hen flocks of Gallus gallus. The EFSA Journal 97. Published 2007. Accessed February 15, 2010.
39. Hopp P, Wahlstrom H, Hirn J. A common Salmonella control programme in Finland, Norway and Sweden. Acta Vet Scand. 1999;91:45–49.
40. Nestle M. Safe Food: Bacteria, Biotechnology, and Bioterrorism. Berkeley, CA: University of California Press; 2003:27.
© 2010 Lippincott Williams & Wilkins, Inc.