The welfare of the laying hen: The caged versus cage-free debate

Egg production facilities in the United States are the cleanest and safest compared with any others.

Students at the University were asked by Compassionate Action for Animals to pay higher residence hall fees to get the University Dining Service to purchase eggs solely from certified-humane, cage-free producers. On Feb. 26, the Residential Housing Association voted down this request 24-9. Compassionate Action for Animals insists that the animal welfare for the hens is improved in cage-free systems. But is the welfare of the hens actually better and worth the extra cost?

The term cage-free does not have a legal definition – it simply means that the chickens are housed without the use of cages. It is also important to note we cannot know how it feels to be a hen – we only can make inferences based on our assessment of their physical state and behavior, taking into account our knowledge of their neural capabilities and in the light of our own experience. Avian and mammalian brains have developed differently – especially in the area of the anatomy of the forebrain. This makes it difficult to speculate about how birds “feel.”

Why do producers keep hens in cages? Decades ago, egg production was based on small flocks of hens kept outdoors on mixed farms. As the demand for animal products increased, farming became more specialized and the average flock size increased dramatically, increasing the labor-load to care for them. A better understanding of poultry physiology and nutritional requirements made it possible to move flocks indoors, protecting the hens from predators and extreme changes in weather. Keeping chickens indoors also provided protection from diseases carried by wild birds. This is particularly important today with the avian flu problem being experienced worldwide.

While moving hens indoors provided many benefits, parasitic problems quickly became apparent. The development of cages to house the hens eliminated these parasitic problems. Improved house insulation and ventilation technology eliminated the problem of condensation that can occur at higher stocking densities. The number of tiers of cages and stocking densities increased. The development and improvement of cages and house design for laying hens is an ongoing process and continues today with research on land-grant universities.

An important factor in evaluating animal welfare is health. A study conducted in the European Union, where non-enriched cage rearing of laying hens will be banned in 2010, made the following conclusions:

Bacterial/protozoa infections are markedly higher in floor-kept birds as compared to those in cages. This is to be expected since intestinal parasites are more likely to survive, reproduce and cause disease problems when hens are in close contact with the droppings.

Reproductive disorders do not seem to be related to any particular housing system but vent pecking was shown to be more common in layers kept in non-cage systems than in conventional cages.

The risk of cannibalism is higher in non-cage systems than in conventional cages. This may be because of the constantly changing micro-population for the hens. It is widely believed by scientists that with chickens there is a limit in the number of individuals that a hen is capable of recognizing. Chickens also have a preference for familiar hens. In small flocks, such as those of caged-laying hens, this means that hens have the opportunity to form stable hierarchies with minimal aggression and hens may learn to tolerate the close proximity of others. In larger flocks, this capacity to form stable hierarchies may be threatened by repeated exposure to unfamiliar hens.

Because of the large numbers of birds kept in floor systems, there is a risk for suffocation by crowding. Chickens panic easily and will quickly pile up in a corner if startled, killing those on the bottom of the pile.

The shell structure of eggs produced in cage-free systems has been found to be weaker than eggs from hens in conventional cages, making it easier for bacterial contamination to increase the food safety risk with cage-free systems.

In general, the level of bacterial eggshell contamination is higher in cage-free systems, related mainly to a higher microbial load of the internal environment of the laying house.

The general conclusion is that the European Union directive to ban cage-layer systems, which was meant to improve the physiological welfare of laying hens, appears, in fact, to increase animal health and food safety concerns, at a huge economical cost to the producers. There is a rumor that the European Union will be backing off its position to ban cages, but that is still speculative at this stage.

In discussions with members of the Compassionate Action for Animals and the Humane Society of the United States, which is backing the “factory farm” campaign, they often talk about space requirements and the chicken’s supposed inability to engage in important behaviors, unable to even spread their wings. The analogy often given is that each chicken has the space equivalent to a single sheet of paper. But this is misleading. First, today’s modern hen is only about 3.5 pounds – what might seem small to a full-grown human, is not as small for a chicken. It’s all relative. Secondly, hens are housed in colony cages, extending the boundaries of the environment significantly. I’ve personally seen hens spreading their wings in these cages many times.

Modern egg production facilities have evolved to provide a safe and wholesome product for today’s consumer. Eggs coming from modern egg-laying production facilities in the United States are the cleanest and safest in comparison to any in the world.

Jacquie Jacob works in the University’s department of animal science. Please send comments to [email protected].