Chickens: laying hens in egg factories

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Chickens are among the most intensively farmed animals, while the consumption of eggs also has a significant impact on their welfare. Chickens have to undergo countless painful procedures in order to be adapted to the unnatural conditions in which they are kept. ProVeg shines a light on the egg industry and suggests some healthy alternatives.

Chickens and their basic needs

Chickens are social animals. In their natural environment, the red junglefowl, which is the domesticated chicken’s closest wild relative, lives in groups of up to 20 hens with one rooster.1 These groups develop a distinct hierarchy, or ‘pecking order’, allowing them to coexist peacefully.2

Chickens spend a significant portion of their time foraging, which includes wandering around, scratching, and pecking at the ground.3 They take regular dust, soil, or sand baths, and groom their feathers regularly to stay clean and healthy. Most of the time, chickens stay on the ground, but they fly up into trees or onto other elevated perches to rest or when they sense danger.

Chickens are intelligent and empathetic individuals

Chickens are clever and sensitive individuals with distinct personalities. Their communication is complex, with at least 24 different types of vocalisations recorded.4 Research has shown that the cognitive capabilities of chickens are comparable to mammals such as cats, dogs, and even primates.5 For example, chickens are capable of comprehending object permanence (understanding that objects outside of view still exist), which exceeds the cognitive abilities of infant humans. Newborn chicks are able to perform complex mathematical operations, distinguish quantities, and tell left from right – just like humans.6

There is also strong evidence of the emotional capacities of chickens. Mother hens display their capacity for empathy when they observe their chicks experiencing stress and, as a result, exhibit signs of stress themselves.7 8 9 Additionally, chickens forge strong friendships and prefer the company of certain chickens over others.10

Modern egg-laying breeds

The egg industry makes a clear distinction between laying hen breeds and broiler chickens which are raised for meat. Laying hens are bred to lay as many eggs as possible, and are kept under artificial lighting designed to further increase laying rates. The result is that these ‘high-performance’ hens lay an average of 300 eggs per year.11 Like their wild relatives (red junglefowl), chicken breeds that have not been genetically selected for their high egg yield lay fewer than 40 eggs per year. As a result of this unnaturally high laying rate, the bodies of laying hens are quickly exhausted. Accidents, diseases, bone fractures, and inflammation of the oviducts are commonplace, as is premature death.

Living conditions in egg factories

Worldwide, over 7 billion chickens are kept inside egg factories, laying more than 1.3 trillion eggs per year. 500 million chicken are kept in Europe alone.12 While conditions vary around the world, most hens are kept in one of four types of husbandry settings: cages, barns, free range, or organic husbandry systems.

Battery Cages

The majority of all laying hens lives in conventional battery cages. These cages provide each bird with a mere 550 cm² of space – smaller than an A4 sheet of paper.13 Although battery cages have been banned in Europe, hens are often confined to ‘enriched colony cages’ instead, which offer only 750 cm² of space per bird. Enriched colony cages are divided into several functional areas and house between 60 and 80 chickens per cage. In both battery and enriched colony cages, cramped conditions prevent hens from being able to satisfy their most basic physical and instinctual needs: walking, stretching their wings, sand bathing, and foraging. About 56% of the European laying stock is kept in cage systems.14

Barn systems

In barn systems, chickens live together so densely that nine chickens are forced to share one square metre.15 Laying flocks in these barns often reach huge sizes. For example, in Germany, up to 6,000 individuals can be housed in one barn.16 In groups this large, chickens are unable to establish the stable social structures they need to ensure peaceful coexistence. This leads to immense stress and constant conflict between hens, with the cramped conditions preventing weaker individuals from being able to escape more dominant and aggressive individuals.17 In the European Union, regulations require that only one third of the space be covered with litter; the rest is usually covered with wire mesh that hurts chickens’ feet. Around 26% of Europe’s laying stock is kept in barn systems.18

Free-range systems

Counterintuitively, ‘free-range’ chickens spend most of their time in conditions very similar to those of barn systems. According to regulations, chickens in free-range systems must have access to the outdoors. However, in practice, doors to the outside are closed on some days, and high stocking densities prevent chickens in the back of the barn from being able to access the door. Additionally, hens may avoid outdoor areas if there is no shelter or vegetation, as they fear being exposed to predators.19 Approximately 14% of Europe’s egg-laying hens live in free-range systems.20

Organic farms

Conditions in organic farm systems are generally similar to those of free-range systems. Chickens may be kept in stocking densities of up to six chickens per square metre. Although colony sizes are restricted by law to 3,000 birds, this still far exceeds the flock preferences of chickens in natural settings, where group sizes do not exceed 20 hens. As a result, conflict, stress, and injury among chickens are still commonplace. Organic farming systems are the only farming systems in Europe in which chickens are not routinely debeaked. Only 4% of the European laying stock are organically farmed.21


In most egg factories, chicks have their beaks trimmed at a young age in order to prevent them from pecking at and cannibalising each other as they grow older, behaviour which is triggered by high stocking densities.22 Debeaking modifies the chicks’ bodies to suit an unnatural and stress-inducing environment, rather than modifying the environment to accommodate the basic needs of the chickens.

The most common method of debeaking is to use a hot blade to cut off the chicks’ beaks. Alternatively, the chicks’ beaks are pressed against a hot metal plate, burning them off. In both cases, these procedures are performed without anaesthetic. Chicks endure severe pain during this experience and may develop chronic beak pain or sensitivity that lasts for the rest of their lives.23

Male chick culling

Because they cannot lay eggs, and their breeding makes them unprofitable to raise for meat, male chicks are considered worthless to the egg industry. Consequently, on their first day of life, male chicks are separated from their sisters and killed. The two most common methods of slaughter are suffocation or being shredded alive in a grinder.

Laying hen culling

The egg industry maximizes its profits by keeping only the most productive laying hens. However, the laying rates of hens naturally decline as they age and laying hens across all farming systems are slaughtered after just one year. They are then replaced with younger, more productive individuals. This turnover leads to the slaughter of several billion hens per year.

According to chicken industry statistics, many hens do not even survive long enough to be slaughtered after their first year. Around 10% die during their first year of life as a result of the strenuous conditions of egg production.24 This loss is referred to within the industry as ‘shortfall’ and calculated as a ‘loss of productive days’.

Cholesterol: health risk of egg consumption

Annually, the world’s population consumes about 200 eggs per capita.25 The consumption of eggs is associated with health risks. For example, eggs have a high cholesterol content and can promote atherosclerosis, which increases the risk of cardiovascular disease. Due to the poor conditions that chickens live in, eggs are the perfect host for salmonella, which can cause diseases in humans and other animal species. Food scandals such as eggs contaminated with dioxin or fipronil present another reason why more and more consumers are reducing their egg consumption or switching completely to healthier plant-based alternatives.

Plant-based egg alternatives are becoming increasingly popular

Eggs are an important ingredient in many cuisines, whether for baked goods and desserts or for mayonnaise and hollandaise sauce. However, due to the industrial production methods used, eggs come at a significant cost to animal welfare, the environment, and our health. There are now healthier, plant-based egg alternatives for every purpose. These include applesauce or bananas for baking, and kala namak for a typical egg flavour, as well as commercially available alternatives.

ProVeg presents the best plant-based egg alternatives and explains how to make creative use of them in the kitchen.

ProVeg supports the availability of plant-based egg alternatives

ProVeg does not only point out healthy, cruelty-free alternatives but also makes them more readily available. ProVeg supports and facilitates a range of vegan events throughout the year, from annual happenings such as VeggieWorld and VegMed to important one-off events such as CEVA trainings and legal and political symposiums. Furthermore, the ProVeg Incubator advises and supports innovative companies that want to enrich the veggie market with their products. This ranges from mentoring early-stage start-ups to consulting for major international supermarket brands and administering the V-Label, which guarantees that a product is either vegan or vegetarian. Find out more about what we are doing to help the world transition to a more plant-based society and economy that are sustainable for humans, animals, and our planet.


1 Brade, W. et al. (eds) (2008): Legehuhnzucht und Eiererzeugung: Empfehlungen für die Praxis. Landbauforschung Sonderheft 322. Braunschweig: Johann Heinrich von Thünen-Institut. Available at: [03.03.2018]
2 Gautier, Z.(2002): Gallus gallus. Animal Diversity Web. Available at [26.01.2018]
3 Hoy, S., (ed) (2009): Nutztierethologie: 35 Tabellen. UTB Agrarwissenschaften, Veterinärmedizin 3312. Stuttgart: Ulmer. pp. 210
4 Collias, N. E. (1987): The Vocal Repertoire of the Red Junglefowl: A Spectrographic Classification and the Code of Communication. The Condor, no. 89 (n.d.): pp. 510–524.
5 Smith, C. L. & S. L. Zielinski (2015): Schlaue Hühner. Available at [03.03.2018]
6 Rugani, R., L. Fontanari, E. Simoni et al. (2009):. Arithmetic in Newborn Chicks. Proceedings of the Royal Society B: Biological Sciences 276, no. 1666 (July 7, 2009): pp. 2451–2460.
7 Nature (2011): Animal behaviour: Chickens feel for each other. 471, no. 7338 (March 17, 2011): 268–268. doi:10.1038/471268c.
8 Edgar, J.L., E.S. Paul & C.J. Nicol (2013): Protective Mother Hens: Cognitive Influences on the Avian Maternal Response. Animal Behaviour 86, no. 2, pp. 223–229.
9 Edgar, J. L., J. C. Lowe, E. S. Paul, et al. (2011): Avian maternal response to chick distress. Proceedings of the Royal Society of London B: Biological Sciences. 278, p.3129–3134
10 Hauser, J. & B. Huber-Eicher (2004): Do Domestic Hens Discriminate between Familiar and Unfamiliar Conspecifics in the Absence of Visual Cues? Applied Animal Behaviour Science 85, no. 1–2 (January 2004): pp. 65–76.
11 Hoy, S., (ed) (2009): Nutztierethologie: 35 Tabellen. UTB Agrarwissenschaften, Veterinärmedizin 3312. Stuttgart: Ulmer. p. 204
12 Food and Agriculture Organization of the United Nations (2017): FAOSTAT Statistics Database. Available at [03.03.2018]
13, 15 COUNCIL DIRECTIVE 1999/74/EC of 19 July 1999 laying down minimum standards for the protection of laying hens
14, 18, 20, 21 European Commission (2016): EU Market Situation for Eggs. Committee for the Common Organisation of the Agricultural Markets. 23. June 2016. Available at [03.03.2018]
16 Tierschutz-Nutztierhaltungsverordnung in der Fassung der Bekanntmachung vom 22. August 2006 (BGBl. I S. 2043), die zuletzt durch Artikel 1 der Verordnung vom 14. April 2016 (BGBl. I S. 758) geändert worden ist
17 Hoy, S., (ed) (2009): Nutztierethologie: 35 Tabellen. UTB Agrarwissenschaften, Veterinärmedizin 3312. Stuttgart: Ulmer. pp. 207 – 209
19 Commission Regulation (EC) No 557/2007 of 23 May 2007 laying down detailed rules for implementing Council Regulation (EC) No 1028/2006 on marketing standards for eggs
22 Bilcík, B. & L. J. Keeling (2000): Relationship between Feather Pecking and Ground Pecking in Laying Hens and the Effect of Group Size. Applied Animal Behaviour Science 68, no. 1 (May 5, 2000): pp. 55–66.
23 Breward, J., & M. J. Gentle (1985): Neuroma Formation and Abnormal Afferent Nerve Discharges after Partial Beak Amputation (Beak Trimming) in Poultry. Experientia 41, no. 9 (September 15, 1985): pp. 1132–34
24 Burch, D. G. S. (2012): Laying Hen Mortality by System – a Welfare Guide? Veterinary Record, 171, no. 25, pp. 649–650. Disponible en [03.03.2018]
25 International Egg Commission (2015): Egg Industry Review 2015. Available at [03.03.2018]

Last updated: 20.03.2018

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