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Humane? An Enriched Cage is Still a Cage

Enriched cage smallThe American Humane Association’s (AHA) farm animal welfare certification program – American Humane Certified – announced in June that it will permit the use of so-called enriched battery cages for laying hens as an option for humane housing.

Humane? My first reaction on hearing this was, “Hey guys, you do realize this is still a cage, don’t you?” But let’s be evenhanded about this and look at the reasoning put forward by the American Humane Association.

The  American Humane Association’s  rationale for this decision is that these cages are “enriched” to allow hens to exhibit natural behaviors. In making this decision AHA states that it has carried out an extensive scientific review of the behavior and welfare of laying hens housed in such systems – mainly looking at research from Europe where conventional cages are soon to be totally banned.

Okay, so I might consider accepting that an “enriched” battery cage possibly offers better welfare opportunities than a standard battery cage. But AHA fails to recognize some key behavioral needs that hens are driven to perform. I am talking about providing the birds with space to run, stretch, flap their wings, and fly; litter and somewhere to dust bathe; and vegetated areas to peck at and forage in. AHA also significantly underestimates the ability of enriched cages to provide adequate nesting and perching.  So what does the research really tell us about “enriched” battery cages? And are they really a humane option? I was pretty confident that a lot of research existed to say some of these behaviors are not wants but programmed driven behavioral needs.

AHA is quite correct in turning to Europe where the bulk of the research has been carried out on enriched cages. In 2012, standard battery cages will be prohibited across the whole of the EU, following legislation first introduced in 1999. In order to facilitate the transfer of egg production from standard battery cages to other systems the EU funded the LayWel project, which examined welfare implications of changes in production systems for laying hens, with a particular emphasis on what the project described as “furnished”  or enriched cages. It may seem like wordplay to insist on this term rather than “enriched,” but the LayWel project makes the valid point that adding a perch or a nest area to a cage can be factually described as furnishing it but that it is a matter of opinion as to whether or not it “enriches” the cage. The LayWel project terms “furnished cage” the more accurate description and it’s the term I will use going forward.

In Europe, legislation lays down specific provisions that must be met by furnished cages. It is not clear whether AHA will require cages to meet the EU legislative requirements or if they will draw up their own standards for cages. The EU legislation requires at least 116 sq. inches of total space per hen. In March 2010, U.S. manufacturer Chore-Time Egg Production Systems unveiled its furnished cage at the Midwest Poultry Convention which only provides 68 sq. inches per bird – less than the current legal minimum for a standard cage in the EU, which requires 85 sq. inches per bird. Even taking the legislation into account, there are a multitude of options for cage design, some of which the LayWel project found can severely restrict the ability of the birds to gain a welfare benefit. For example, furnished cages in the EU must provide 6 inches of perch space per bird, but if the perches are arranged in a crosswise manner to fit them into the cage it may be difficult for the birds to actually use them.

On the topic of perches, you might wonder how it is possible for a bird to get up on a perch in a cage. Your picture of a bird roosting is probably similar to mine – a bird way up in a tree or high up in the rafters of a barn. High perches make birds feel safe from predators and other threats, but in a furnished cage the perch is likely to be less than 3 inches off the floor – and the wire top of the cage will be just 15 inches above that. You might argue that there are no predators that can get into cages but this misses the point. Chickens originate from jungle fowl of southern Asia and, regardless of the cross breeding and hybridization of the species, their behavior remains pretty much the same. For the chicken to be free from fear and distress it needs to be able to get up on a perch where it feels safe (Olssen and Keeling 2000; Cooper and Albentosa 2003). The EU Animal Health and Welfare Panel states, “Resting and perching are important aspects of birds’ welfare. Roosting at night on an elevated perch is a behavioral priority” (AHAW, 2005a). At just a couple of inches off the floor, the perch in a furnished cage will be seen by the hen as part of the floor and not as a perch (Tauson, 1984).

Let’s move on to one of the other supposed benefits of a furnished cage – the fact that it has a nest area. It is well established that hens place a high value on a secluded nest site. Research has shown that hens will move weighted doors and squeeze through gaps to get to what they consider a suitable site.

The reduced space in cages in general and the small area set aside for nesting in furnished cages in particular is a problem. Hens naturally lay at the same time each day – early in the morning – so there could be a queue of hens waiting their turn to get into the nest area. Early work on furnished cages (Guesdon and Faure, 2004) showed that the number of eggs laid in the nest area varied between 43 percent and 68 percent in a trial comparing four designs of furnished cages with standard cages. This suggests that the nest areas were not always satisfactory for the hens. While LayWel project research showed a higher percentage of use of the nest area in furnished cages versus standard cages, the fact that a nest is provided is not the point; hens must find it acceptable or they will not lay eggs in it. This is not an issue for non-cage systems which provide far more space and more numerous nest boxes.

Space to “turn around, spread their wings and lie down” is quoted as being a benefit of a furnished cage. Let’s take the EU space per hen of 116 sq. inches per bird in a furnished cage. Is this really enough? Well, the bird can definitely stand in this space and it can probably lie down. But can it really spread its wings and turn round with ease? How much space does this take?

Dawkins and Hardie (1989) looked at the average space required by a hen to carry out basic needs: turning around requires an average space of 198 sq. inches, stretching her wings requires 138 sq. inches, and flapping her wings requires 290 sq. inches. These figures are all far greater than the space provided per bird in a furnished cage. Of course, each furnished cage holds multiple hens so total space will be more than one hen needs; so you could argue that within the cage there is more than enough room for a particular hen to flap her wings at any given time. Of course, she’d have to count on the cooperation of all the other hens to be out of her way and not trying to stretch their own wings at the same time. And, we’re not even considering the need of the bird to run, fly, dustbathe and forage.

In natural conditions, hens spend 50–90 percent of their waking time foraging, making up to 15,000 pecks a day (Webster, 2002; Picard et al, 2002). No wonder feather pecking is an issue in cages – imagine the frustration of being deprived of doing what could take up to 90 percent of your day? That natural drive and energy must be directed somewhere and, sadly, the only option is to peck at the other hens you are trapped with. Furnished cages fail to meet the need for foraging behavior and making only the most minimal of accommodations for pecking.

Dustbathing is another key natural behavior (Lindberg and Nicol, 1997) that the furnished cage is supposed to facilitate. True dustbathing involves the hens lying down and throwing litter or other loose material over the feathers of their backs and wings, rubbing it in, and then shaking it out. When hens do not have a suitable area and litter in which to dustbathe, they still go through the motions of dustbathing. This is known as “sham dustbathing” and research suggests that it does not properly satisfy the motivation of hens to dustbathe. In furnished cages, sham dustbathing on the wire cage floor takes place far more frequently than in the littered area (Lindberg and Nicol 1997) with two thirds of dustbathing taking place outside of the designated area. At first it was thought that competition for space was contributing to this, as well as the fact that, like egg laying, dustbathing tends to take place at the same time each day. But further research (Olsson and Keeling 2002) shows that there was no relationship between sham dustbathing and competition for use of the litter area, suggesting that the area, the type of litter provided, and the depth of litter in furnished cages just does not meet the hens’ requirements, and so they treat all areas as equal when dustbathing. Like the nest box, it’s not just the provision of a designated area that is important; it’s whether the hens see it as acceptable. In non-cage systems where there is appropriate litter on the floor and/or access to outdoor areas there is no evidence of sham dustbathing (AHAW, 2005b).

From the points raised above it is clear that furnished or enriched cages provide very few potential benefits compared to standard cages – and in no way compare with the kind of high-welfare pasture based systems supported by Animal Welfare Approved (AWA). No wonder then that European welfare groups such as Compassion in World Farming are calling for a ban on “enriched” cages, and that in Germany all cage systems – including furnished cages – will be prohibited beginning in 2012. While AWA can agree that almost anything is better than a standard barren battery cage, let’s not kid ourselves that the enriched cage is anything other than an inhumane confinement system.


AHAW (2005a) Opinion of the Scientific Panel on Animal Health and Welfare on a request from the Commission related to welfare aspects of various systems of keeping laying hens (Question EFSA-Q-2003-092), adopted by the AHAW Panel on 10th and 11th November 2004. The EFSA Journal, 197: 1-23.

AHAW (2005b) Report of the Scientific Panel on Animal Health and Welfare on a request from the Commission related to welfare aspects of various systems of keeping laying hens (Question EFSA-Q-2003-092), accepted by the AHAW Panel on 14th and 15th September 2004. Annex to The EFSA Journal, 197: 1-23.

Cooper, J. J. and Albentosa, M. J. (2003) Behavioural priorities of laying hens. Avian and Poultry Biology Reviews, 14: 127-149.

Dawkins, M. S. and Hardie, S. (1989) Space needs of laying hens. British Poultry Science, 30: 413-416.

Guedson, V. and Faure, J. M. (2004) Laying performance and egg quality in hens kept in standard or furnished cages. Animal Research, 53: 45-57.

Lindberg, A. C. and Nicol, C. J. (1997) Dust-bathing in modified battery cages: Is sham dust-bathing an adequatesubstitute? Applied Animal Behaviour Science, 55: 113-128.

Olsson, I. A. S. and Keeling, L. J. (2000) Night-time roosting in laying hens and the effect of thwarting access to perches. Applied Animal Behaviour Science, 68: 243-256.

Olsson, I. A. S. and Keeling, L. J. (2002) No effect of social competition on sham dustbathing in furnished cages for laying hens. Acta Agriculturae Scandinavica, Section A, Animal Science, 52: 253-256.

Picard et al (2002) Visual and tactile cues perceived by chickens. In J. M. McNab and K. N. Boorman (eds.), Poultry Feedstuffs: Supply, Composition and Nutritive Value. CAB International.

Tauson, R. (1984) Effect of a perch in conventional cages for laying hens. Acta Agriculturae Scandinavica, 74: 193-209.

Webster, A. B. (2002) Behaviour of chickens. In D. D. Bell and W. D. Weaver (eds.), Commercial Chicken Meat and Egg Production. Kluwer Academic Publishing.

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