The Experimental Use of Chickens and Other Birds in Biomedical and Agricultural Research

V. Birds Used in Agricultural Research

 A researcher whose experiment consisted of shaving hens naked with sheep shears in heat-stress studies for the egg industry said that the shaving procedure was “very humane, just like a haircut.” —(University of Minnesota researcher Craig Coon in a phone interview with Karen Davis, July 25, 1994; see Peguri and Coon.)

Until 1988, when he retired, Dr. Eldon Kienholz (1928-1993) was a full professor, specializing in poultry nutrition in the Department of Animal Sciences at Colorado State University. In an interview, Dr. Kienholz, who chose to retire early rather than continue to perform cruel experiments on birds, talked about one of his research projects.

Q.Could you give an example of the kind of research you did?

A."Yes. I knew that wings and tails of birds were unnecessary to commercial production of poultry meat, so I did research to show that a grower could save about 15 percent of feed costs by cutting off the tails and wings of broiler chicks and turkey poults soon after hatching. I gave papers on that at national meetings, and attracted a great deal of interest.

Q.What caused you to become skeptical about your work? Was it a utilitarian consideration? A moral twinge?

A. "A moral twinge. Somehow it didn’t feel right to be cutting off the wings of newly-hatched birds. Later, some of them couldn’t get up onto their feet when they fell over. It wasn’t pleasant seeing them spin around on their side trying to get back onto their feet, without their wings." —Karen Davis, Prisoned Chickens, Poisoned Eggs: An Inside Look at the Modern Poultry Industry 1996, p. 89.

Vivisection and the Poultry and Egg Industries

The decision to consume animal products involves one morally with millions of animals beyond those used strictly in food production. Huge numbers of chickens and other farmed animals are subjected to painful and degrading experiments on behalf of the food industry each year. Their status as flocks and herds ensures that vast numbers will be used up in agricultural experiments simulating commercial production situations. For example, 2,880 brown hens were used in an experiment published in 2002 in which light intensity, debeaking (“beak trimming”) and other stressors were imposed on the birds to study for the umpteenth time why hens in battery-cages peck at each other (Hartini et al.).

In 1988, the Federation of Animal Science Societies (FASS) published a Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching (“revised” in 1999) based on the 1985 edition of the Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health (NIH). The equivocation of the Guide is shown by the fact that while professing to encourage scientists to seek improved methods of farmed animal care and use, the authors “accept” procedures that “may cause some temporary discomfort or pain” if these procedures are “warranted in the context of agricultural production.”  This leaves the door wide open, while the proviso that painful and otherwise distressful experiments should be “performed with precautions taken to reduce pain, stress, and infection” is compromised by the fact that normal agricultural experiments on live chickens and other farmed animals are either deliberately designed to produce pain, stress, fear, and infection, or else they cannot be performed without producing these conditions.

Those wanting an idea of the kinds of experiments that are conducted on chickens, turkeys, ducks, and other domestic fowl in the United States and elsewhere should consult the pages of Poultry Science and the Journal of Applied Poultry Research, as well as the many avian disease and veterinary journals devoted to such research. Countless experiments on birds are never published at all. In addition to traditional experiments involving food deprivation, debeaking, slaughter, and heat stress, poultry are increasingly being used in all kinds of transgenic and cloning experiments on behalf of the biomedical industry and the food industry. They are being used to develop the methodologies of future research, to “iron out wrinkles” like how to insert alien genes into birds via infectious viral carriers that won’t replicate to become new, more virulent and uncontrollable strains of virus. Or they are being used or targeted for use in genetically-manipulated “behavior modification” studies to reduce their intelligence and behavioral needs--like the need to dustbathe--to enable them to live apathetically in stressful environments (Turner 2002, p. 59). To the researchers, these birds are nothing but cheap large-scale biosystems whose experimental use is already in place, unhampered by welfare regulations. At a time when society has begun to demand less cruel treatment of birds and other animals raised for food, genetic engineers are pushing the technologies of farmed animal abuse in whole new directions.

Here are some of the stress experiments that were done on behalf of the poultry and egg industry in the 1980s.   

The USDA bibliographical series publication Stress in Poultry: January 1979 – August 1990 lists 311 representative studies, including these titles:

• Action of stressors on the organism of hens and turkeys for the purpose of extending the period of their productive use. (Russia)
• Application of tranquilizers in the breeding process to control stress in poultry. (Russia)


• Avian leukosis virus infection and shedding in Brown Leghorn chickens treated with corticosterone or exposed to various stressors. (UK)
• Comparison of the stressfulness of harvesting broiler chickens by machine and by hand. (Canada)


• Dynamics of urea in the liver of cockerels in the early post-incubation period under physiological and model stress conditions. (Czechoslovakia)


• Effect of acute heat stress and its modification by adrenaline and adrenolytic drugs in chickens. (India)


• Effect of calcium deficiency on survival time of young chickens acutely exposed to high temperature. (USA)
• Effecting of fasting [i.e. starvation] and acute heat stress on body temperature, blood acid-base and electrolyte status in chickens.  (UK)
• Effect of heat stress early in life on mortality of broilers exposed to high environmental temperatures just prior to marketing. (USA)
• Effect of prolonged heat stress on adrenal weight, cholesterol, and corticosterone in White Pekin ducks. (USA)
• Effect of stress-caused molt on the conditioned reflex activities of poultry. (Russia)
• Effect of supplemental corticosterone and social stress on organophosphorus-induced delayed neuropathy in chickens. (The Netherlands)
• Effects of adding acid or base to the diet on semen of heat-stressed, aging broiler breeder males. (USA)
• Effects of claw removal and cage design on the production performance, gonadal steroids, and stress response in caged laying hens. (USA)
• Effect of heat stress on day-old broiler chicks. (USA)
• Effects of thiouracil and thyroxine on resistance to heat shock in hens.  (USA)
• Effects of transportation on the tonic immobility of fear reaction of broilers. (UK)
• Heat stroke in domestic fowl. (India)
• Influence of body weight and cage height on the ultimate bending force and stress of the radius and tibia of layers. (USA)
• Physiological responses of heat-stressed broilers fed Nicarbazin. (USA)
• System for studying multiple concurrent stressors in chicks. (USA)
• Results of cold stress in strains of turkey selected for growth rate and egg production. (USA)
• Stress by immobilization, with food and water deprivation, causes changes in plasma concentration of triiodothyronine, thyroxine and corticosterone in poultry. (Australia)

Shell-less Egg Experiment on Hens Using Balloons and Tampons

A 1980s experiment that does not appear in the above directory was done on hens for the egg industry. In a study published in Poultry Science in 1984, researchers in the Poultry Science Department, Alabama Agricultural Experiment Station, and Veterinary Diagnostic Laboratory at the University of Auburn manually inserted inflated balloons, shell membranes and tampons into the uteri of hens and gave them inflammatory and immunosuppressive drugs to determine “possible causes of shell-less eggs, a multimillion dollar loss to US egg producers.” The presence of these objects in the hens’ uteri caused high fever, vomiting, diarrhea, and death. According to the researchers, “The balloons were the most difficult of all the materials to insert into the uteri. If a hen had not accepted the balloon after it had been inserted into the uterus 3 or 4 times, the bird was not used. A punctured uterus was believed to be the cause of death of one hen in this group. In most cases the materials remained in the uteri from 1 to 48 hr. In one instance, a Rely tampon was expelled within 1 hr, but the bird still died. In other cases, tampons or balloons remained in the uteri overnight and were sometimes enclosed in shell membranes. Some treated hens died within 8 hr; however, most hens died between 14 to 48 hr after insertion.” The experimenters concluded that the hen’s reproductive system might serve as a model for studying human toxic shock syndrome (Roland, et al.).

Chickens as a Model for Prenatal Mammalian Stress in Factory Farming

Researchers in the Department of Animal Science at Iowa State University did a study to determine whether the chicken may be developed as a model by which the “mechanism” of  “profound deleterious effects” of stress during gestation in mammals can be elucidated. “Exposing a pregnant mammal to stressors causes behavioral and physiological alternations in her offspring (‘prenatal stress’); however, elucidation of the underlying mechanism is hindered by an inability to control maternal compounds that may affect the fetus. We designed this experiment to determine if the autonomously developing chicken embryo could be developed as a model for prenatal stress.”

The researchers treated 16-day-old embryos with the stress hormone corticosterone and subjected them to extreme heat (40.6 degrees C), then observed the behavior of the survivors following debeaking: roosters chasing each other and “pecking aggression.” They killed the birds and weighed their adrenal glands. They concluded that the administration of corticosterone during incubation “replicated some, but not all, of the effects seen in prenatal stress in mammals” and that “[f]uture research directed at understanding prenatal stress in cattle, sheep, and swine will allow maximization of both productivity and animal well-being” (Lay, Jr. and Wilson).

Partial Beak Amputation Experiments

“The emotion-laden word ‘mutilation’ is sometimes used in describing husbandry practices such as removing a portion of a hen’s beak. . . . [However] removal of certain bodily structures, although causing temporary pain to individuals, can be of much benefit to the welfare of the group.” —James V. Craig, poultry researcher at Kansas State University, Domestic Animal Behavior, 1981, pp. 243-244.

Crowded confinement of poultry leads to pecking disorders caused by restriction of the birds’ normal outdoor activities including food gathering, dustbathing, and exploring the environment. To combat this problem, poultry and egg producers “beak trim” chickens and turkeys and “bill-trim” ducks with hot blades and in some cases laser beams or electrical sparks (FASS, 1999, p. 63; Duncan 2001, p. 215). Debeaking is very painful to birds, for as veterinarian Robert Clipsham explains in his article “Beak Injuries,” the thin skin underlying the horny covering of the beak is composed of “a dense mixture of blood vessels, connective tissues and nerves” (Clipsham, p. 45).

The painfulness of debeaking was established in the 1960s by the Brambell Committee, a group of veterinarians and other experts appointed by the British Parliament to investigate animal welfare concerns arising from the intensive farming practices described in Ruth Harrison’s book Animal Machines (1964). Yet debeaking experiments continue to be done, adding to the weight of evidence as to why debeaking (or “beak trimming”) should not be done. For example, beak trimming causes a hen’s heart rate “to increase 100 beats per minute,” and it takes her heart “from six to 10 minutes” to recover from the time of infliction (Eleazer 1986, p. 384).  Beak trimming causes both short-term and long-term suffering in birds and prevents them from eating and preening normally (Duncan 1993, p. 5). Here are some of the debeaking experiments that have been published since the 1980s:

• In 1985 researchers recorded the abnormal and spontaneous neural discharges from the beak stumps of experimentally debeaked birds for up to 83 days following the mutilation (Breward and Gentle).


• In 1987 researchers published a study that looked at the behavioral effect of “partial beak amputation (beak trimming)” on twelve 16-week-old Brown Leghorn hens housed individually in battery cages. They concluded that the pain of debeaking offset “any increase in welfare to the flock brought about by beak trimming” (Duncan, et al., p. 479).


• Using the standard industry procedure of  “cutting and cautery,” researchers beak-trimmed sixteen 16-week-old Brown Leghorn hens to see if there were acute and chronic painful consequences. They concluded that behavioral changes in the birds “provide evidence for possible chronic pain in birds following partial beak amputation” (Gentle, et al., p. 149).


• To study the “sex effects” of beak trimming on large white turkeys, researchers debeaked 60 baby male turkeys and 60 baby female turkeys (young turkeys are called “poults”) with an electronic trimmer, “which burns a small hole through the upper beak so the tip of the beak falls off after three to seven days” (Cunningham, et al.).


• A 1992 review article on “Beak Trimming Effects on Performance, Behavior and Welfare of Chickens” references more than 20 studies from the 1950s in which chickens and turkeys were experimentally debeaked to record the effect on the birds’ behavior patterns, fearfulness, feathering, mortality, food intake, and body weight (Bray, et al. 1960 cited in Cunningham, p. 134).


• That same year researchers debeaked 900+ hens “to compare beak treatment effects on pullets of three genetic stocks” while killing a similar number of male chicks who hatched inescapably in preparation for this study which began with “approximately 2,100 eggs of each stock” (Craig, et al., p. 1831).


• In 1997, The New York Times reported that researchers at Nova-Tech Engineering in Minnesota received a patent for “a device that exposes the top beak of a bird to high-frequency radiation, while shielding the bird’s tongue and lower beak.” The top beak is supposed to fall off after two weeks leaving the bottom beak for eating and drinking.  The procedure is said to reduce “a substantial amount of pain and shock.” associated with the hot blade debeaking machine (Riordan, p. D2).    

Contact Lens Experiments

In a study published in the Journal of Applied Poultry Research in 1992, a researcher at Purdue University described his experiment on the Effect of Red Plastic Lenses on Egg Production, Feed per Dozen Eggs, and Mortality of Laying Hens (Adams 1992). The hens’ eyes were fitted with red contact lenses. “Seven hundred and ninety Dekalk L pullets, 10 weeks of age, were obtained from a local hatchery. Beaks of all pullets [young hens] had been trimmed at day one by using a hot blade; nontrimmed pullets were not available at that time.” The hens were divided into three caged groups including hens with no lenses, hens with lenses inserted at 12 weeks old, and hens with lenses inserted at 16 weeks old. At 17 weeks old, the hens were moved to the caged-layer house whereupon “considerable mortality” occurred among birds with lenses between 2 and 8 weeks following the move. The researcher attributed the high mortality to the hens’ “inability to find their food” [in the trough in front of the battery cages] and suggested putting the birds in the cages first and inserting lenses in a lighter shade of red later.

In 1991, United Poultry Concerns investigated the use of red contact lenses after receiving written complaints from employees in the poultry unit at California Polytechnic State University, in San Luis Obispo (UPC). The employees charged that a lens experiment on caged hens sponsored by a company called Animalens was causing severe eye infections, abnormal behavior, and blindness, and preventing the hens from closing their eyes normally because the lenses were so large. The hens were “pecking the air” and “rubbing their eyes repeated on their wings.” The Animalens trainers who inserted the lenses did not even wash their hands first. The hens received no veterinary care or treatment during or after the experiment. They developed painful corneal ulcers and blindness and were left to languish with the lenses in their eyes for months in the poultry unit. A year later, a local newspaper reported that the surviving hens were being sold “one by one, mostly to individuals who take them home for slaughter” (Greene).

In 1997, the Journal of Applied Poultry Research ran a study in which Israeli agricultural researchers examined the “effect of contact lenses on egg production, egg weight, fear response, and mortality in White Leghorn hens.” Two hundred hens were housed in cages of five birds per cage. Red contact lenses were placed on the eyes of 100 hens and the other hundred served as controls. Within two weeks, some of the hens with lenses developed eye irritations. After seven months, “a large proportion of the experimental hens were severely affected.” The researchers concluded that contact lenses “appear to be associated with an increase in eye irritations and thus their application is discouraged” (Gvaryahu, et al., p. 449).   

Behavioral Experiments to Fit Birds to Factory Farming

"By selecting for chickens that could tolerate the social stress, we also got chickens that could tolerate environmental stress."
—Purdue University poultry researcher Bill Muir, on breeding hens who are "better adapted" to battery cages (Sigurdson).

Instead of producers changing their operations to fit the birds, agricultural geneticists such as Bill Muir think that “adapting the bird to the system makes more sense” (Sigurdson, p. 48). Since the 1980s, Muir has been working to develop a strain of hens whose normal pecking behavior is reduced, thereby eliminating the “need” for debeaking. In the course of his studies, Muir says that a power outage in his laboratory revealed that his docile hens fared better under the intense heat that resulted than the other hens did, so he set up a heat-stress experiment which led him to conclude that his hens not only peck less but have more tolerance for environmental stress.

Forced Molting Experiments

"We passed on through the egg barn. . . . When the lights came on, the cackling and clucking rose to a cacophony, accompanied by the sound of thousands of beaks pecking on metal."
—Kathy Geist 1991.

North Carolina State University researchers advise duck producers to “remove all feed (sweep the troughs clean) from the breeder flock” for at least 9 days or “until a 30% decrease in bodyweight occurs” (Gary S. Davis and Ken E. Anderson 1992).

Induced molting is commonly used by the layer industry in the United States to stimulate multiple egg-laying cycles in hens. Although there are several methods to induce a molt, feed removal remains the primary means of achieving the egg-laying pause. However, recent research has shown hens infected with Salmonella enteritidis (SE) during the feed removal period had more severe intestinal infections than unmolted hens.
—Peter S. Holt and Robert E. Porter 1993, p. 2069.

Since the 1950s and 1960s, the U.S. poultry and egg industry has used a starvation procedure known as “forced molting” to manipulate egg production in female birds used for commercial egg production and for breeding. Their food is removed from 4 to 21 days and the survivors are reused for another laying cycle. For decades, poultry researchers have starved hens in experiments duplicating this procedure, which they basically invented. According to an article in ILAR News,  “Several variants of force molting techniques have been developed by the Experimental Stations and agricultural faculty of land grant universities. All methods involve stress induction by deprivation of food or water” (Tillman, p. 32). For example, in 1967, University of California poultry researcher Donald Bell described 9 different food deprivation experiments with laying hens in which he considered it “interesting” that there was a “trend towards more mortality using the severe starvation methods”-- no food for 10 days, no water for three (Bell).

Three decades later Bell, still at it, published an article on the effects of starving hens for 10 or 14 days.  He concluded that food deprivation “can range from l5 to 18 days, but the use of these extremes should be examined carefully and economic considerations should be part of any such analysis” (Bell and Kuney, p. 206).

Forced Molting and Salmonella Enteritidis Studies

In the 1990s, USDA researchers performed numerous starvation experiments on hens in which they starved the birds, usually for 14 days, after orally infecting them with Salmonella enteritidis bacteria to study the link between forced molting, immune system breakdown, and Salmonella enteritidis (SE) in hens and their eggs. Their research was prompted in part by the Centers for Disease Control and Prevention’s identification of eggs as the primary source of SE food poisoning in the United States in the 1980s. Here are three of the forced molting studies conducted by USDA immunologist Peter Holt and his associates at the Agricultural Research Service laboratory in Athens, Georgia.

• A study by Holt published in 1992 describes the effect of food deprivation for 12 days and for 14 days on the immune systems of an unidentified number of laying hens in four separate experiments involving daily blood tests and vivisection of chick embryos injected intravenously with the blood from these hen by cutting a window in the shell “using a Dremel Moto-tool No. 395 (Dremel, PO Box 1468, Racine, Wisconsin) and a round disc cutting wheel (No. 409).” The results showed that forced molting  (“induced molting”) “probably has a negative effect on the cellular component of the immune system of the moulted birds” (Holt 1992, p. 165).


• In this study, hens were starved in three experiments after receiving oral doses of a nalidixic acid-resistant strain of Salmonella enteritidis by gavage “to examine the effect of the 14-day feed removal protocol on the course of SE infection in White Leghorn hens at 20, 40, and 74 wk of age” (Holt and Porter 1992, p. 1843). About 50 of 100 hens used in this study received no food, and half of all hens used in the study were infected with Salmonella enteritidis bacteria.

Starvation-Study Hens Are Driven to Pluck and Consume Each Others’ Feathers

In a study published by Holt in 1995, force-molted hens were shown to transmit Salmonella enteritidis more readily than unmolted hens to adjacent cagemates. In his paper, Holt notes that the hens in his laboratory who are being starved will pluck and consume the contaminated feathers of other starving hens—“[I]t was possible that the feathers on the hens in the current study became contaminated with S. enteritidis and then were subsequently plucked and consumed by hens in adjacent cages. Such ingestion has been observed during these and other molting experiments” (Holt 1995, p. 248). Asked about this, Holt replied, “Regarding your query about the plucking and ingesting feathers, I am not sure that this is a result of hunger or just boredom. With chickens, it is hard to separate the two” (letter to Karen Davis, March 10, 1998).

Hens More "Athletic" After 3 Weeks Without Food

"If you were there, to stick your finger in the cage to catch them, they’d be more athletic—capable of escaping my grasp, suspended upside down--struggled more effectively than birds that were full fed." —Poultry researcher Bruce Webster in a phone interview with Karen Davis on October 15, 1998, explaining why he considered starving hens for three weeks to be humane.

This study by poultry researcher Bruce Webster was conducted at The University of Georgia. Webster sought to “approximate a commercially induced molt” by withholding food from 65-week old hens for three weeks. He videotaped the behaviors of 36 food-deprived hens and 36 control hens at intervals until the food-deprived hens lost 35 percent of their body weight. Webster concluded that “an induced molt that uses a long period of feed withdrawal need not cause harm to hens, and it may even improve their survivability” (Webster 2000).

However, poultry welfare scientists Joy Mench (UC-Davis) and Ian Duncan (University of Guelph, Ontario) disputed Webster’s conclusions, calling his experiment “badly designed” with a “flawed discussion.” For example, “he did not observe the hens when they are most likely to experience frustration, during the morning and late afternoon when their feeding motivation is greatest.” He nowhere indicated “what he would have accepted as suffering,” while “the meager evidence he presents does suggest suffering: the increased aggression suggests severe frustration and the increased non-nutritive pecking, some of which was stereotyped, suggests severe frustration and extreme hunger, and the reduced activity suggests debilitation” (Duncan and Mench, p. 934).

Forced Molting Experiments by Japanese Researchers

Forced molting experiments are also done in other countries such as Japan. For example, a paper published in Avian Diseases in 1995 called Intratracheal Infection of Chickens with Salmonella enteritidis and the Effect of Feed and Water Deprivation (Nakamura, et al.1995) involved two experiments in which a number of approximately 170 chickens used in the study were infected, starved, deprived of water, and subsequently killed by cervical dislocation to fill a research gap in which the researchers claimed that the effect of stress on airborne infection or intratracheal infection had not yet been demonstrated (p. 854).

Experiments on Alternatives to Forced Molting by Food Deprivation

“A recent campaign by the activist group United Poultry Concerns generated more than 5,000 cards, letters, and signed petitions to the offices of the United Egg Producers (UEP) in Atlanta, calling for the egg industry to discontinue its practice to force hens to molt. . . . UEP reported that, given mounting pressure to discontinue induced molting, including questions from government agencies, it has received a grant from the American Egg Board to conduct research into molting without feed withdrawal.” —UEP plans research about induced molting practice, Feedstuffs, August 7, 2000, p. 8.

The U.S. poultry and egg industry has known for decades that it could achieve the same forced-molting results by feeding hens an altered diet instead of starving them, but since feeding the birds costs money and starving them doesn’t, and since no one was looking over industry’s shoulder and no federal welfare laws exist to protect poultry in the United States, the industry chose starvation. However, as the link between food deprivation and diminished immune responsiveness, predisposing hens to Salmonella enteritidis infection, was added to the bad publicity about the cruelty of this procedure in the 1990s, industry and government started funding new studies to “find alternatives” to the forced molting of hens by means of food deprivation.

In 1993 researchers described a low-energy, low-density, low-Ca [low calcium] diet that when given in limited amounts induced molting as effectively as long-term food deprivation (Rolon et al.). Because the hens were fed through the entire molt procedure, the physiological impact was said to be “less traumatic” than starvation and the effect on S. enteritidis infection lessened. Therefore, a further study was conducted that compared forced molting by food deprivation with molting induced by special feeding and the effect of the two regimes on intestinal S. enteritidis infection.

In that study, which included three experiments and 137 hens, the birds were infected with oral doses of Salmonella enteritidis and about a third of them were starved for 14 days. Hens were then killed to examine their intestines for the presence of the SE bacteria. The results indicated that “molt induction, using a molt diet, will not put hens at risk for the severe intestinal infection observed in birds subjected to feed removal” (Holt, et al. 1994, p. 1267).

With financial assistance from the Bayer Corporation, USDA researcher Peter Holt reported doing studies in the late 1990s involving the administration of two drugs, Enrofloxacin and Avigard, to help reduce Salmonella enteritidis infection in hens fed a restricted diet to induce a molt (Holt 1998).

• In 2001, University of California poultry researcher Donald Bell (the architect of forced molting by food deprivation going back to the 1960s) reported a study in which he compared “hens fed 10 to 12 lbs. per 100 hens of a corn diet with dicalcium phosphate, limestone, and a vitamin-mineral pre-mix per day with no salt” and hens deprived of food for 6 to 13 days followed by feeding the survivors a molt diet. The results indicated that “molting hens using a feed removal method was superior to the no-salt continuous fed method, although excellent results did occur on one farm with the no-salt method” (Bell 2001 reported in Koelkebeck et al. 2001, p. 1).
• In current studies by Ken Koelkebeck and his colleagues at the University of Illinois, hundreds of hens (e.g. 336 hens in one experiment) are being used to compare egg laying productivity in hens deprived of food from 4 to 10 days and hens fed various combinations of ingredients including wheat middlings, ground corn, soybean meal, meat and bone meal, vitamins and minerals. In a paper presented at the WATT Poultry Summit Focusing on Bird Welfare in the Commercial Layer Industry, October 16, 2001, Koelkebeck concluded that “if the commercial egg industry is forced by animal welfare/rights pressures to move towards using molting programs which utilize a non-feed removal method, then feeding a wheat middlings, corn-wheat middlings combination, or corn gluten feed diet to induce a molt might be considered” (Koelkebeck et al., p. 12).
• Similar studies are being conducted by poultry researcher Kenneth Anderson at North Carolina State University. Anderson compared hens in four programs including one in which hens were starved for 13 days. The programs were designed to force hens to lose weight down to what they weighed at the beginning of their second laying cycle. The non-starved hens lost weight and stopped producing eggs similar to the starved hens. Thus, Anderson says, it appears that laying hens can be successfully molted without ever being starved or nutritionally deprived for body maintenance (Research aims at fast-free molt).

Feather Pulling Experiments

Referring to “previous studies” reported in P.D. Sturkie’s Avian Physiology (4th edition, 1986) as well as to other such studies done by himself and his associates, Michael Gentle and a colleague at the Edinburgh Research Station in Scotland set up an experiment in which they pulled out the feathers of 16 adult Brown Leghorn hens to measure the birds’ pain reaction in terms of their cardiovascular, behavioral, and electroencephalographic responses to the procedure (Gentle and Hunter). The birds were hatched and reared in cages at the Institute of Animal Physiology and Genetics Research. In preparation for the experiments, the researchers anesthetized the hens with intramuscular and intravenous injections and implanted cannulas (tubes) in their arteries and inserted EEG electrodes into their heads. After the birds recovered from the anesthesia, they were partially restrained in wooden cradles for the feather-pulling. According to the researchers, the cradle “may have affected both the behavioural and physiological responses of the birds” who while “free to move their head, neck, wings and legs,” were prevented “only from making gross ambulatory movements” (i.e. from getting away). Regarding their behavioral observations the researchers state:

The behaviour of the birds altered throughout the sequences of feather removals but this change was not directly related to the number of feathers removed or to the site of removal. The first feathers removed resulted in the birds becoming agitated with jumping, wing flapping and, or, vocalisation. At this stage the removal of back or tail feathers was more likely to produce agitation and vocalisation than those removed from the leg or breast. The continual removal of feathers did not produce an exaggerated escape response; instead they were observed shortly after feather removal to crouch in the cradle with the tail feathers and head lowered in an immobile state. During this immobility the eyes were periodically closed and the immobility alternated with periods of alert behaviour. This alternating behaviour persisted during the three minute intervals between feather removals but there were few periods of immobility two minutes after feather removal. On the occasions when feathers were removed while the birds were immobile the alertness following feather removal was considerably attenuated so that little or no behavioural response was seen when the feather was removed (p. 97).

Gentle and Hunter describe subjecting individual hens “to the removal of individual feathers” which they pulled out by hand “in one continuous pull.” To investigate any possible regional differences, “two feathers were pulled out randomly in each of the following regions: leg, cape, cape adjacent to the wound site of cannula insertion, back, breast, and tail” (p. 96). At the end of the experiment the birds were killed with sodium pentobarbitone. The researchers concluded that “feather removal is likely to be painful to the bird and feather removal by flockmates can be categorised as a welfare problem” (p. 95).

Featherless Chicken Experiments

"It’s a prime example of sick science and the suggestion that it would be an improvement for developing countries is obscene."
—Joyce D’Silva, Compassion in World Farming, quoted in New Scientist, May 21, 2002.

"The only positive outcome of this sick science is that it shows the nadir of depravity to which a violent, animal-based diet leads and thus encourages more people to become compassionate vegetarians."
—United Poultry Concerns News Release, May 23, 2002."It’s not enough that they’re factory-farming these birds. They have to make their lives totally miserable."
—Shira Skolnik, Director of Hakol Chai, an animal rights organization in Israel quoted in The New York Times, May 24, 2002.

"What horrors will these monsters think of next?"
—Fiona Cheek, letter to United Poultry Concerns, May 30, 2002.

Intensively raised poultry suffer agonizingly from the build-up of heat in the crowded buildings from which they cannot escape. Their metabolic effort to cool themselves increases the amount of heat generated under these conditions (Brown 1993; Muirhead). Rather than improve the living conditions for these birds, scientists are trying to engineer birds who can withstand prolonged and intense heat. For example, scientists at Alexandria University in Egypt put DNA from the heat-resistant bacteria Streptococcus agalactia into chicken eggs and then reared the chicks in a temperature of 25 degrees C (95 degrees F). Some of the birds showed tissue damage in their testes, liver, gizzard, heart, and spleen (Fiky and Mehana 1998 cited in Turner, pp. 28, 69).

In May 2002, Avigdor Cahaner, a professor of quantitative genetics at Hebrew University’s Faculty of Agricultural, Food and Environmental Quality Sciences, announced his creation of a featherless chicken. He said that the bird is designed to withstand mass production temperatures in the hot climates in the Middle East and thus eliminate the need for expensive cooling systems for raising poultry in such places. To obtain the featherless chicken, Cahaner says that he crossbred a mutant strain of featherless chicken discovered and bred at the University of California, Davis, with “broiler” chickens, and that a few dozen of his featherless chickens are being housed at the university’s agriculture school. Soon they plan to kill and eat some of these chickens, he said.

Previously, featherless chickens were bred at the University of Connecticut in the late 1970s (Bennet 2002) and maintained at Clemson University in South Carolina in the early 1980s (Meatnews.com 2002). Cahaner dismissed any suggestion that his research is cruel-- “All these welfare people that said it’s cruel should see what happens to [intensively confined] chickens in hot climates.” (In fact, their feathers help to cool chickens as well as keeping them warm and protecting their skin [North and Bell 1990, p. 16]). Cahaner says his research is “helping evolution,” observing that millions of years ago human beings had fur (Bennet).

• To find out whether chickens’ feather follicles harbor harmful microbes during slaughter, USDA Agricultural Research Service scientists bred featherless chickens, who do not have feather follicles, to compare with feathered chickens. “By the use of artificial insemination, the offspring of featherless roosters and commercial broiler breeder hens were bred to produce both feathered and featherless chicks.” These birds were given Campylobacter bacteria orally a week before slaughter, during which slaughter “the birds were handled in alternating batches of four feathered and four featherless chickens.” The researchers concluded that the presence or absence of feathers did not affect the level of breast skin bacteria (Durham).

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