From children's books to advertising, consumers often see idyllic images of hens scratching in the dirt and pecking around the barnyard. However, these pictures can distort how most eggs are produced today.
Differences in housing
Though eggs were once gathered from flocks that lived outdoors, by the early 1950s, egg farmers began seeing benefits to raising hens indoors. Today, the majority of hens are raised in one of three types of housing: conventional cages, cage-free housing and enriched cages.
Each housing system has advantages and disadvantages in terms of animal well-being, according to Dr. Joy Mench, animal science professor at University of California-Davis and a researcher leading hen well-being research with the Coalition for Sustainable Egg Supply (CSES).
"In conventional cages, the behavior of hens is very restricted — they have little freedom of movement and are unable to perch, nest or forage," Mench said. Conventional cage systems account for approximately 95 percent of all eggs produced in the United States.
"Cage-free systems permit much more freedom of movement and also allow the hens to perform the behaviors that they cannot perform in conventional cages," Mench said. "But hens in cage-free systems also tend to have more health problems and higher mortality than hens in conventional cages'"
A third type of housing has recently been introduced in the U.S., which is essentially a hybrid of the other two housing systems.
"The new enriched colony systems were designed to be intermediate between conventional cages and cage-free systems," Mench explained. "They are larger than conventional cages and contain perches, a nesting area and a foraging area. They still do not allow the hens as much freedom of movement as a cage-free system, but they preserve many of the hen health advantages that are associated with conventional cages."
Animal well-being, food safety & affordability
CSES researchers are working to understand better how each of these hen housing systems affects various issues, including animal well-being.
"This research will offer additional insights into other aspects of each system, as well, including food safety, environmental impact, worker health and safety and food affordability," Mench said. "Ultimately, this will allow researchers and others to understand the potential impacts, advantages and disadvantages of each housing system as they work to better understand a sustainable egg supply."