Conventional cage housing was widely adopted in the 1960s for its improvements to hen well-being and egg safety. Over the years, research was conducted and housing has been modified to continually improve hen well-being and provide high-quality eggs. In 2002, egg farmers adopted UEP Certified guidelines for cage housing based on recommendations of an independent Scientific Advisory Committee. In 2006, UEP Certified Cage-Free guidelines were implemented. To utilize current research, the UEP Certified guidelines were updated in 2016.
UEP is a member of the Coalition for Sustainable Egg Supply, which conducted the most comprehensive study to date to evaluate hen housing and potential impacts on food safety, the environment, hen health and well-being, worker health, egg safety and food affordability.
The goal of the CSES research was to understand pros and cons of conventional cage, enriched colony and cage-free housing, which may help egg production stakeholders make informed decisions. Research has found each housing style has positive and negative impacts and tradeoffs. All indoor housing provides quality hen care and safe eggs when properly managed.
Hens are housed inside climate-controlled barns in stacked rows of cages. Each cage gives birds continual access to water and food. The cage has wire mesh floors that allow manure to drop through to a belt below, which keeps manure away from the birds, as well as their eggs, food and water. After a hen lays an egg, it gently rolls off the slightly-sloped mesh flooring onto an egg-collection belt. The belt moves the egg to processing, where it is checked for imperfections, cleaned and packaged.
Cage-free eggs are laid by hens that are able to roam vertically and horizontally in indoor houses and have access to fresh food and water. Cage-free systems vary from farm-to-farm, and can include multi-tier aviaries. They must allow hens to exhibit natural behaviors and include enrichments such as scratch areas, perches and nests. Hens must have access to litter, protection from predators and be able to move in a barn in a manner that promotes bird welfare. A cage-free aviary is shown here. Manure belts help keep manure away from birds. Most of the time, hens lay the eggs in the nest box, where the eggs then rolls off the slightly-sloped floor onto a collection belt. The belt moves the egg to processing. Eggs can also be laid in the litter or elsewhere in the barn, and then they must be collected by hand.
Hens in enriched colony housing live in smaller groups and have space for natural behaviors like perching, scratching and dust bathing. Curtains provide hens with privacy during nesting. Hens are housed inside climate-controlled barns in stacked rows of enclosures, with continual access to water and food. Each enclosure has wire mesh floors so manure can drop through to a belt below to keep manure away from the birds, eggs, food and water. After a hen lays an egg, it gently rolls off the slightly sloped wire mesh floor onto an egg-collection belt, which moves the egg into the processing area.