Choosing the “Best” Eggs? Let Us “Egg” Splain

A reader recently asked about housing conditions for egg-laying hens, wondering which housing system is most humane.

The Coalition for Sustainable Egg Supply examined this issue to help support greater understanding of hen housing, so we looked to their research for insight. The study compared hens in three housing systems:

  • Conventional cages, in which hens are stacked in cages
  • Cage-free housing, in which hens are allowed to roam freely through sections of the barn
  • Enriched colony, which is a hybrid between the two systems in which hens are in larger cages that contain perches, nesting and foraging areas

Check out an infographic that explains the housing systems.

So which housing system had the happiest, healthiest hens? While happiness can’t be measured in hens, the research shows the answer to which was healthiest is not necessarily clear cut, as each housing system was found to have positive and negative aspects.

In addition to assessing aspects of food safety, food affordability, the environment, and worker health and safety, researchers studied a number of factors that impact animal well-being. You can view an interactive infographic to evaluate each of those elements and determine which eggs to choose based on what matters to you. Following is a summary of the key animal health and well-being findings.

Exhibiting Natural Behaviors: Hens in the cage-free and enriched colony systems had freedom to exhibit natural behaviors, regularly using perches and nest boxes. In the cage-free houses, they also dust-bathed. Even though hens in the enriched colonies had access to scratch pads, they did not use them very much. Due to their enclosures, hens in the conventional cages had limited ability to exhibit natural behaviors.

Bone Health: Hens in cage-free housing had stronger bones overall, likely because of their ability to “exercise.” However, they also had more keel bone (breastbone) fractures, which may have been caused by failed attempts to fly. Hens in conventional cages had the highest incidence of foot problems.

Mortality Rates: The death rate of hens was more than twice as high in the cage-free system than in either conventional cages or enriched colonies. The leading causes of death in all housing systems were hypocalcemia (low blood calcium levels) and egg yolk peritonitis (due to leakage of egg yolk into abdominal cavity). The cage-free houses had the highest incidence of hens being cannibalized or excessively pecked.

Physiological Health: In order to determine if the hens were experiencing stress, blood samples were drawn and adrenal glands measured. Overall, that physiological data did not demonstrate the presence of acute or chronic stress for hens in any housing system.

Food Safety: When properly managed, it was found that each of the three housing systems researched can provide safe, high quality eggs.

Understanding that each housing system has positive and negative aspects in each of the elements researched, we encourage you to choose eggs produced by hens housed in the system that you feel is best.

Eggs” by John Morgan is licensed under CC BY 2.0.