Just the facts. From the experts.


When you're shopping for eggs, do you look at the labels and wonder about the welfare of the hens? For example, The Mother Fitness blog examined the differences, while One Mom's World toured a modern egg farm. In thinking about the chickens who lay those eggs, which housing system does the best job of caring for the chickens?


We spoke with Dr. Joy Mench, animal science professor at UC Davis, about the welfare of raising hens in cages.

Dr. Joy Mench


Best Food Facts: Isn’t it obvious that the welfare of laying hens is better if they are cage free than in cages?

Dr. Joy Mench: "Each kind of hen housing system has welfare advantages and disadvantages. In conventional cages, the behavior of hens is very restricted – they have little freedom of movement and are unable to perch, nest or forage. 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, but hens in cage-free systems also tend to have more health problems and higher mortality than hens in conventional cages. The new enriched colony systems were designed to be intermediate between conventional cages and cage-free systems. 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 do preserve many of the hen health advantages that are associated with conventional cages.

“The effects of different housing systems on hen welfare, as well as other crucial aspects of egg production such as environmental impacts, worker health and safety, food safety, and economics, need more scientific study. I am currently co-leading a research project on sustainable egg production that will result in information that will help both producers and customers make informed decisions about these housing systems.”


Best Food Facts: There are videos online showing hens stuck in cages or dead hens left in cages with live hens. Wouldn’t it be easier to check on the hens and prevent these problems if they aren’t in cages?

Dr. Joy Mench:"Trapped, sick or dead hens can be hard to find in any housing system. In cage systems, it can be particularly difficult to thoroughly inspect the upper and lower cage levels. However, inspection can also be difficult in non-cage systems because hens can be concealed inside the nest boxes, in poor-visibility areas underneath the perches or tiers, or on high perch levels. Given the large flock size in all commercial laying hen systems, both cages and cage free, it would not be surprising if a few trapped, sick or dead hens were overlooked during any particular inspection."



Editorial Note: The Center for Food Integrity, the sponsor of Best Food Facts, facilitates the The Coalition for Sustainable Egg Supply (CSES). CSES is working to better understand the impact of various laying hen housing systems on a sustainable supply of eggs. To do this, researchers at Michigan State University and the University of California-Davis are currently conducting a commercial-scale study of housing alternatives for egg-laying hens in the U.S. The first research flock was placed in April 2011. The study will be replicated over two flocks with conclusion in 2014 and results reporting to follow.


Read additional Best Food Facts posts related to eggs:


Add a Comment

Craving more food facts? Read on!

Part Two: Eggs – Organic, Cage-Free, Free-Range… What’s The Difference?
Organic Food: How Much is Imported?
Are Organic Foods Worth the Extra Cost?