Battery Cage Chickens

The space provided to hens in battery cages is not sufficient for them to stand upright, turn around, stretch, flap their wings, lie down, groom themselves, build nests, engage in litter bathing, or fulfil normal social urges. Unsurprisingly, hens living in such conditions suffer poor physical and mental health, and the eggs they produce are less nutritious.Battery cages are being phased out in Europe and parts of the U.S. in favour of more humane methods, but Canada and many areas of the United States are lagging in making the shift. However, a recent Harris/Decima poll found that 72% of Canadians would pay more for humane food, and 63% support a complete ban on battery cages (Vancouver Humane Society, 2009).

Battery Hens Cannot Engage in Normal Behaviours

Free-Range Chickens, Woodleywonderworks, Flickr

Renowned animal behaviourist Desmond Morris asserts that “Anyone who has studied the social life of birds carefully will know that theirs is a subtle and complex world…The brain of each bird is programmed with a complicated set of drives and responses that set it on the path to a life full of special territorial, nesting, roosting, grooming, parental, aggressive and sexual activities…All these are denied the battery hens.”

According to Dr. Konrad Lorenz, Nobel Prize winner and father of modern ethology, “The worst torture to which a battery hen is exposed is the inability to retire somewhere for the laying act. For the person who knows something about animals it is truly heart-rending to watch how a chicken tries again and again to crawl beneath her fellow-cage mates to search there in vain for cover.”

Caged Hens Suffer Serious Health Problems

Under normal circumstances, a hen spends much of her life walking around, flapping her wings, stretching and preening, and without being able to engage in such behaviours, hens suffer severe physical problems, including bones that become so brittle they snap. Dr. Michael Baxter (formerly of the Scottish Agricultural College) emphasizes that “hens are restricted from exercising to such an extent that they are unable to maintain the strength of their bones…The increased incidence of bone breakage which results is a serious welfare insult.”

Dr. John Webster of the University of Bristol’s Department of Clinical Veterinary Science agrees that the severe restrictions imposed on the mobility of hens causes “injuries to feet and feathers, and exacerbates the development of osteoporosis, leading to bone fractures and chronic pain.” The Canadian Coalition for Farm Animals cites a variety of studies indicating that 80-89% of battery hens suffer from osteoporosis.

Dr. Bernard Rollin of Colorado State University’s Department of Animal Science notes that “Battery cages are responsible for a variety of injuries, as birds are sometimes trapped in cages by the head and neck, body and wings, toes and claws, or other areas. In addition, steep [slanted] floors can cause foot deformities…”

Other physical problems associated with battery cages include metabolic and respiratory diseases, painful foot lesions, and slow death via starvation and paralysis due to spinal compression. In addition, battery cage hens are often deliberately starved to increase egg production, a process called forced molting. The practice further increases the risk of bone breakage and death, according to the Canadian Coalition for Farm Animals.

Caged Hens Are Prone to Pathological Behaviours

Dr. Baxter asserts that in the barren, cramped space of a battery cage, hens suffer “a chronic state of social stress, perpetually trying to get away from their cage-mates…” Dr. R.B. Jones of the Roslin Institute’s Welfare Biology Group agrees, noting that “Rearing chickens in impoverished environments leads to apathy, boredom, fear, and abnormal, often harmful behaviours.” For example, battery hens regularly pluck one another’s feathers out, sometimes creating open wounds, and some even engage in acts of cannibalism. Because they cannot escape from one another, portions of their beaks are sliced or lasered off to prevent these frustration attacks, leading to chronic pain.

Professor of Zoology Dr. Lesley Roberts (University of New England, Australia) attributes feather pecking and other unnatural behaviours to the stress of overcrowded, restricted, noisy cage environments where hens suffer “abnormal levels of sensory or social stimulation caused by excessive tactile contact with cage mates and continuous auditory stimulation produced by the vocalizing of huge flocks housed in the same shed…”

Eggs Laid by Battery Cage Hens are Less Nutritious

A number of studies conducted over the years have shown that eggs laid by chickens with access to outdoor pasture are more nutritious (see Nutrition: Free Range Eggs vs. Battery Cage Eggs for more information).

Additional information on battery cages, current campaigns, and resources can be found on the Canadian Coalition for Farm Animals website.

For a guide to interpreting confusing egg claims and certifications, see Egg Labels. For more food and drink articles, see the main Nutrition and Food page.

References:

• Canadian Coalition for Farm Animals. (n.d.). “The Truth About Battery Cages and “Facts About Our Food – Battery Hens”; (October 2005). “Battery Cages and the Welfare of Hens in Canada: A Summary of the Scientific Literature.” HumaneFood.ca.
• Schmidt, S. (2009). “Cracking Egg Labels.” Natural Health, October 2009, FindArticles.com.
• The Humane Society of the United States. (n.d.). “Synopsis of Expert Opinions on Battery Cages and Hen Welfare.” HumaneSociety.org.
• Vancouver Humane Society. (28 December 2009). “Results Suggest Majority of Canadians Want 2010 to Be Happier for Hens.” ChickenOut.ca.