"Beak trimming," according to the United States Department of Agriculture, "is a routine husbandry procedure practiced in the poultry industry to prevent feather pecking and cannibalism."
More than 90% of the country's 296 million egg-laying hens live in cages for most of their lives, which range from 80-110 weeks long. United Egg Producers guidelines state that cage floors must be at least 67 square inches per bird, about 8 by 8 inches, a few inches smaller than a standard piece of paper. In these cages, hens are unable to engage in natural behaviors nesting, dustbathing, foraging, flying, wing-flapping, or walking, which the USDA says, "results in stress, which leads to the expression of harmful behaviors."
As of January 1, 2012, these cages are banned in Europe.
Feather pecking and cannibalism, "can lead to suffering and death" but can be mitigated with beak trimming. Most trimming is done on growing farms, where the chicks grow into egg-laying hens. It is usually performed with a hot blade beak trimming machine before the chicks reach ten days old. This method "is likely to be acutely painful" and cause "pain... of a relatively short duration," according to a 2011 article published in Applied Animal Behaviour Science.
However, Gregory says that beak trimming is a "scientifically humane proven method, similar to trimming one's finger nails."
A new method using an infrared light is now being used by approximately thirty percent of U.S. egg producers, according to Dr. O'Sullivan, including in Hy-Line's hatcheries. When this infrared treatment is used, "no nerves have infiltrated to the beak tip yet," and therefore this is viewed as a "more humane procedure," O'Sullivan said.