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Sara Shields

April 12, 2008

Nathan Runkle
Executive Director
Mercy For Animals

Dear Mr. Runkle:

I hold a doctoral degree from the University of California, Davis, in Animal Behavior and have more than ten years of experience as a research scientist, teacher, and consultant in animal welfare, with an emphasis on the well-being of poultry. What I viewed on the video footage you sent me on March 27 is a disheartening example of the failure to recognize the sentience of laying hens and a complete disregard for their welfare.

It is well-established in the scientific literature that birds are fully capable of feeling pain and of suffering. All avian species have a highly developed nervous system with complex nociceptive (pain) capacity.1

In the section of the video designated “Killing,” farm personnel clearly fail to use euthanasia techniques that would result in a quick death. Egg producers have a variety of options for euthanizing sick or injured birds, including using a Modified Atmosphere Killing (MAK) cart,2 which appeared to be available for use at the farm shown in the video. The MAK cart was designed for the purpose of depopulating birds. It is unclear why personnel depicted in this video chose to subject birds to obvious pain and suffering when other means are available. Stepping on a bird or twisting her neck is absolutely NOT an acceptable method for killing a chicken. However, both of these methods are shown in the video. The hens were undoubtedly in acute pain and continued to suffer a protracted, slow death, as the video clearly shows they are not dead when left.

The video also shows that birds were subjected to unnecessarily rough handling, likely causing stress and fear as they were transferred to and from cages. Laying hens are fragile animals and are prone to skeletal weaknesses and their bones are easily broken3,4 if they are not handled carefully. At the end of the egg-laying cycle, it is common for hens to suffer from broken bones as they are removed from battery cages.5 Placing pullets in cages and removing them in the manner depicted in the video would likely result in bruising, injury, and bone fractures.

If operated correctly, a MAK cart is one of the most humane, commercially available methods of killing many hens at once on the farm. However, carbon dioxide is an acidic, pungent gas and, when used at high concentrations, is aversive and probably distressing to the hens.6,7

Laying hens confined in battery cage systems, such as the one depicted in the video, have very poor welfare due to severe behavioral restriction imposed by the small, barren cage environment. Chickens normally display a wide variety of behavior patterns and are driven by their complex, inquisitive natures. Caged hens such as those in the video are unable to engage in normal nesting, perching, dustbathing, scratching, foraging, exercising, running, jumping, flying, stretching, wing-flapping, or even walking more than a few steps. Behavioral restriction results in very poor welfare.8

Confinement to cages can further compromise welfare by damaging plumage or causing injury. Crowded cages are abrasive to the integument, can rub off feathers, and damage the underlying skin. Hens can become trapped or injured by loose wires, poorly designed fixtures, or facilities in need of repair. Given the extremely low ratio of farm personnel to hens on a typical commercial egg operation, individual hens who have become injured are likely to remain unnoticed and unattended. Some hens shown in the video have injuries, infections, cloacal prolapse, and show signs of possible disease. Many of the injured birds are clearly suffering, and some are without a doubt in great pain.

Severely injured animals who will not receive treatment and are unlikely to recover should be euthanized immediately. It is unacceptable to place or leave an injured bird in a cage where she will languish indefinitely without treatment.

Egg producers expect a 5% mortality rate. Birds can die from injuries, trauma, internal ailments, or from becoming metabolically overtaxed from laying nearly one egg every day. All of these forms of pathological morbidity involve some degree of pain and suffering, and some hens undoubtedly experience a prolonged and agonizing death, since individual veterinary care is, as a rule, not provided on today’s commercial egg farms.

Cages are inherently cruel, and the suffering, injury, and death of hens on farms are unfortunately and unacceptably commonplace. However, the actions of personnel captured in the video add a further element of inhumanity to these birds’ already severely compromised state of well-being. Work on a typical egg farm can be difficult, dirty, and tiring. Nevertheless, there is no excuse for the inhumane treatment of animals, and persons who engage in blatant mishandling of animals should be held accountable.


Sara Shields, Ph.D.

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