Background:Assessing hen health and welfare is difficult and requires the consideration of many factors including freedom from disease, ability to perform specific behaviors, and protection from housing-specific challenges. Unfortunately, it is not easy to say that one housing system is better than another as hen welfare is more readily influenced by the attributes of a system (such as space, perches, etc.) which may negatively impact a com-ponent of welfare. The usual case is that changing one housing attribute to improve a specific ele-ment of hen welfare leads to a conflicting result that impairs another element of the hen’s welfare. For instance, providing hens with more space so that they can roost allows the hen to perform a natural behavior, which she has a high degree of motivation to perform; however, this environment also causes increased incidence of broken bones, due to miscalculated landings on the perch or floor. Thus, learning to manage the hen’s welfare in all production systems is the key to improving hen welfare.
Housing Options and their Challenges:There are four main housing types that can be catego-rized as: conventional cages, furnished cages, non-cage systems (barns or aviaries), and outdoor sys-tems. The advantages of conventional cages are that they allow for thorough cleaning, which de-creases disease and some parasites; however, due to close proximity when hens do get disease or parasites they spread rapidly. The disadvantages of conventional cages arethat they limit the expres-sion of behavior, and bone breakage can occur, if not careful when the hens are removed from the cage. Furnished cages have the advantage of allow-ing the hen to perform a fuller repertoire of be-havior and hens have lower risk of bone breakage compared to conventional and more extensive systems; however, due to increase complexity of the environment they can harbor pests such as the red-mite. Non-cage and outdoor systems allow a full expression of hen behavior; however, diseases, parasites, cannibalism and broken bones can all become a challenge to hen welfare. Mortality is generally lower in furnished cages when compared to conventional cages, and mortality can reach un-acceptably high levels in non-cage systems.
Recommendations:Hens can experience stress in all housing types, and no single housing system gets high scores on all welfare parameters. Like-wise, no single breed of laying hen is perfectly adapted to all types of housing systems. Addition-ally, management of each system has a profound impact on the welfare of the birds in that system, thus even a housing system that is considered to be superior relative to hen welfare, can have a negative impact on welfare if poorly managed. The right combination of housing system, breed, rear-ing conditions and management is essential to opti-mize hen welfare and productivity.