Which is worse, the chicken or the egg?

Which came first, the chicken or the egg? It’s always interesting to ponder on this question. However, if we want to talk about our food choices and how they relate to animal welfare, there is probably a more important question. Which is worse, eating chicken or eating eggs? When I was young, I thought that consuming eggs did not harm chickens, since there is no need to kill a chicken to extract their eggs. I also thought that since chickens always lay eggs, we were just consuming their by-products. I loved eating chicken and eggs. I had a grilled cheese and egg sandwich almost every day. KFC was my favourite fast-food restaurant. It seems I’m not the only one. In 2021, we slaughtered 73.7 billion chickens, produced 140 million tons of chicken, and consumed 90 million tons of eggs. Every year, the world supplies and consumes more chicken and eggs.1,2 In fact, 82% of the farm animals we raise are chickens.3 The weight of all broiler chickens combined is three times greater than the weight of all other birds on Earth.4

Some people think that vegans don’t eat eggs because eggs have the potential to become chickens. However, the commercial eggs that we eat are not fertilised. In reality, the reason that many vegans don’t eat eggs is due to the exploitation and killing of hens that is common practice within the egg industry. In this post, I will describe the process of raising and slaughtering chickens to produce chicken and eggs. In the following sections, I will describe acts of violence and cruelty, and show some related images. As a result, some readers may experience uncomfortable feelings. Parents should decide whether to allow their children to see this content. However, if we want to make an informed choice about whether to consume animal products such as chicken and eggs, learning about the process by which these products get to our plates is an important first step.


Chicken meat


Selective breeding

Broilers are the most common breed of chicken raised for meat. Broilers evolved from the red jungle fowl through selective breeding. To create the broiler chicken, we selected and bred chickens that grew the fastest and provided the highest quantity of meat. Modern broilers weigh five times more than in the 1950s, and grow three times faster than the red jungle fowl. As the muscles of broiler chickens grow rapidly, organs such as their heart and lungs do not develop as well. Broiler chicken’s legs cannot bear their own weight very well and hence broilers can become lame or unable to move.1 Broiler chickens regularly endure broken legs, foot problems, and heart attacks as a result of their rapid growth.5 Metabolic abnormalities, decreased immunity, and skeletal problems are also common.4 The image below shows a chicken that is unable to walk, as well as a pile of broiler chickens that died due to the previously mentioned problems. The chicken industry has prioritised profit over the welfare of chickens by implementing selective breeding in this way.

A chicken unable to stand under their own weight and a pile of dead broiler chickens

A chicken unable to stand under their own weight and a pile of dead broiler chickens on the farm. Farm Transparency Project.6


Hatchery

Broiler chicken eggs are fertilised and sent to a hatchery. After hatching, weak or sick chicks are sorted from the healthy chicks, and killed in either a macerator or a gas chamber filled with carbon dioxide.7 The image below shows chicks being killed in a gas chamber.

Chicks suffocating in a carbon dioxide gas chamber

Chicks suffocating in a carbon dioxide gas chamber and the resulting pile of dead chicks. Scenes from Dominion.8


Factory farm conditions

Broiler chickens that make it past the hatchery are typically raised in factory farms. An unofficial analysis based on data from the USDA (Unites States Department of Agriculture) estimated that 99.9% of broiler chickens are raised on factory farms.9,10 Typically 20,000-50,000 broilers are kept in one shed at a time. That is equivalent to about 42 chickens per square metre.5 Fully grown broilers usually have about an A4 sheet of paper’s area of space to themselves. The image below shows a broiler chicken factory farm. Due to the lack of space, broilers are not able to freely walk around, rest, or express natural behaviours. Farmers typically leave on artificial lighting for most of the day in order to encourage more feeding and hence accelerate growth. As a result, the chickens sleep quality is reduced. As there are so many chickens in one place, high concentrations of ammonia are released from their faeces. If the farmer does not sufficiently ventilate the shed, this ammonia can burn the chicken’s eyes, lungs, and skin.11

Broiler chicken shed

Broiler chicken shed. Farm Transparency Project.6

Some chickens are unable to access food or water due to the previously mentioned leg injuries.12 Farm workers kill injured chickens, weak chickens, or chickens that are unlikely to grow to slaughter weight. In addition, if the farmer accidentally raises too many chickens at once, the excess chickens are killed on the farm. Small chickens are killed in a carbon dioxide gas chamber or macerators. Farm workers stretch and break the necks of larger chickens.13

Broilers are usually slaughtered only 5-7 weeks after birth. In comparison, the red jungle fowl is able to live up to 11 years of age. In other words, the large chickens that we eat grow to that size within only 5-7 weeks and then we kill them. Due to selective breeding, broilers are unable to survive very well without humans. Even if we did not slaughter them, there is a high probability that they would die due to the range of health problems that we have bred into them.1 RSPCA (Royal Society for the Prevention of Cruelty to Animals) and other animal welfare organisation approved chickens experience much of the same things.12 If a broiler chicken becomes infected with a severe zoonotic disease, the farmer typically must kill all of the chickens that they raise, in order to prevent the disease from spreading to other shed  or farms. One method is to fill the chicken shed with carbon dioxide. However, it takes up to 22 minutes for the chickens to to die with this method.14 Preventing the spread of infection may seem like a good thing, but by intensively raising so many chickens together in one space, we have artificially increased the risk of such events occurring.


Transportation

Before slaughter, the chickens are grabbed from the shed and forced into cages. During this process, the chickens may suffer wing fractures and bruises, their wings or feet may get stuck in the cage, or they may even die. Chickens experience a lot of stress and fear when grabbed by their legs or head.15 If the worker grabs the chicken’s leg too quickly,  the chicken’s hips may dislocate.11 Following this, the chickens are transported by truck to the slaughterhouse. During transportation, chickens may experience extreme temperatures or dehydration.16 In order to prevent the chicken’s carcass from being contaminated with faeces, the workers do not give the chickens food or water before transportation. The longer the transport lasts, the more likely it is that the chickens will die in transit.17

Broiler chickens being forced into transportation crates

Broiler chickens being forced into transportation cages. Farm Transparency Project.6


Slaughterhouse

At the slaughterhouse, slaughter workers shackle the legs of the chickens. The chickens are hung upside down and transported to the stun bath via a fast-moving chain. The image below shows this process. Shackling a chicken’s legs and hanging them upside down is a painful and stressful experience, especially if the chicken is heavy or has a leg injury.18

Chickens being shackled and hung upside down at the slaugherhouse

Chickens being shackled and hung upside down. Scene from Dominion.8

The chicken’s head is forced into a bath filled with electrified water. This bath is designed to stun the chicken’s brain. However, if a chicken flaps their wings while hanging, they may prematurely touch the water and receive an electric shock. Furthermore, this method does not always completely stun the chicken. For example, because several chickens are forced into the bath at once, the larger chickens receive less current and hence they are stunned less effectively than smaller chickens.18 If the chicken bends their neck and does not enter the bath, then they experience the subsequent slaughter consciously. Electrocution is the most common stunning method. In a similar way to pig slaughterhouses, stunning via gas chambers is somewhat better for the welfare of chickens, but this is a less common practice.15,18 After being stunned, the chicken’s neck is passed over a rotating blade and cut open. The pictures below illustrate this process.

Chickens having their throats cut and bleeding out. Farm Transparency Project6 and scene from Dominion.8

To make it easier to remove the feathers, the chicken’s body is lowered into a bath full of hot water. However, if the blade does not completely cut a chicken’s neck, then the chicken is finally killed by drowning in the hot water. In these instances, the chicken’s skin turns red as they do not bleed out.15 The photo below shows the scalding and decapitation process.

Scalding tank and chicken decapitation processes

Scalding tank and decapitation processes. Scenes from Dominion.8


Eggs


There are many similarities between the egg and chicken industries. For example, the processes of killing chicks, transportation, stunning, and slaughter is almost identical. In this section, I will describe the unique characteristics of the egg industry.

Selective breeding

Broilers and laying hens both evolved from the red jungle fowl, however, they are now different breeds. Red jungle fowls lay 10-15 eggs per year. However, these days due to selective breeding, layer hens lay about 300 eggs per year.19 That is almost one egg every day. Eggs contain a lot of calcium and hence there is little calcium left for the hen’s bones as a result of laying so many. From this, hens more easily develop osteoporosis, keel bone fractures, and broken bones. These injuries are chronically painful and reduce the ability of the hens to move.20-22


Hatchery

In order to replace slaughtered layer hens, a selection of eggs are fertilised and sent to the hatchery. After hatching, the chicks are separated by sex. Male chicks are not very useful to the egg industry, since they cannot lay eggs. Additionally, the males of this breed produce significantly less meat and grow more slowly than broiler chickens. Hence, the egg industry does not benefit from raising these male chicks for chicken. Hence, the egg industry selects a few male chicks for reproduction, but kills the overwhelming majority of them. Small hatcheries usually kill male chicks in a gas chamber. Large hatcheries usually force the male chicks into a macerator, which is similar to a large blender.23 The image below shows this process. Methods are being developed to inspect and destroy male eggs before hatching.24 However, even if this technology was deployed globally, it will only solve one of the many welfare related issues of the egg industry.

Chicks falling into the macerator at the hatchery

Chicks falling into the macerator at the hatchery. Farm Transparency Project.6

Weak female chicks or sick female chicks are also killed in this way. Healthy female chicks are spared this process, but still endure suffering later on. To prevent hens from attacking each other, the beak and claws of female chicks are cut off. This type of mutilation causes both acute and chronic pain.23 The image below shows beak amputation.

Cutting off the beaks of female chicks

Cutting off the beaks of female chicks. Scene from Dominion.8


Factory farm conditions

The majority of layer hens are raised on factory farms. An unofficial analysis based on USDA data estimated that the 98.2% of layer hens are raised in factory farms.9,10 About 90% of eggs come from cage factory farms. In this case, the laying hens live in a space about the size of an A4 sheet of paper, and hence they are unable to walk or stretch their wings. The photo below shows the conditions on a factory farm for laying hens. Eggs from laying hens raised in sheds can legally be promoted with a cage free label.25

Laying hens raised in cages and sheds

Laying hens raised in cages and sheds. Farm Transparency Project.6

Due to the stress associated with these conditions and the inability to engage in natural foraging behaviors, laying hens tend to peck at each other’s feather or eat each other’s skin and blood. So, as previously mentioned, we remove the beaks of female chicks without anaesthesia to try an prevent this.5,26,27 Beak trimming is a painful process, however, it lowers negative social interactions later on. However, beak trimming does not completely eliminate this behavior. Even though beak trimming is a little better for the welfare of hens, we have again artificially created a situation where this is necessary. If we did not raise so many laying hens in a small area at once, this behavior would be less severe.

Laying hens are forced to undergo molting, which is the shedding of feathers, so that they can lay eggs for a longer period of time. During this period, the farmer does not feed the hens for 5-14 days or feeds them a nutritionally deficient diet. This is a very stressful period for the hens and the probability of death during molting is increased. After molting, the egg production rate and quality increases, and new feathers grow. If the farmer had not implemented the forced molting process, they would have to raise more laying hens at the same time to produce the same amount of eggs.28 So there is a trade-off between raising less hens, but they have to undergo forced molting, or raising a larger number of hens, but they have to endure factor farm conditions and ultimately slaughter. There is, of course, a third choice… In addition to forced molting, laying hens lose feathers due to stress, infection, or pecking each other.

Layer hens that have lost their feathers

Layer hens that have lost their feathers. Farm Transparency Project.6

After 72 weeks, the egg production rate of laying hens decreases. The farmer cannot economically justify continuing to feed these hens and hence they are sent to the slaughterhouse.27 In contrast, the red jungle fowl can naturally live up to 11 years old.1 In other words, after the hen cannot provide us with any more benefit, we exchange their life for meat. Chicken flesh from layer hens is usually included in processed chicken products or pet food.

But what about free range farms? The photo below shows layer hens inside of a free range farm. As you can see, these laying hens aren’t really out in the field and free. Originally, there was no regulation on what could be called free range. In some countries, the label is a little more regulated. For example, if a hen has the opportunity to access to the outdoors during the day or if they have the opportunity to forage for food, then the eggs from that laying hen can be claimed as free range. Hence, you can raise hens inside a shed and legally label your eggs as free range as long as there is a small outdoor area available.25 This definition also does not guarantee that hens will go outdoors every day, but it just requires them to have the possibility of going outdoors. If many laying hens are kept in the same shed, many hens may not actually get to go into the small “free-range” area. The image below shows a free-range area that could be accepted under this definition. Of course, there are farms that do raise chickens in pasture, but they are less common. These farms are better for the welfare of chickens, but there are still many welfare issues. In the end, no matter what farming method is used, most chickens that we raise experience transportation, stunning, and slaughter.

Free-range hens in a shed and a small outdoor area

“Free-range” hens in a shed and a small outdoor area. Farm Transparency Project.6


Conclusions and reflection

So, after reading this, can you answer the key question? Is it worse to eat chicken or eggs? If we didn’t kill layer hens, would the egg industry become ethical? It is theoretically possible to raise hens and extract eggs without any pain, death, or suffering, but this is not realistic or economical. In order to provide a sufficient quantity of affordable eggs to meet our demand for eggs, it is currently necessary to kill the majority male chicks and raise hens intensively. In order to reduce the price of eggs, it is necessary to kill laying hens with a low egg output, and sell their flesh. So, when we buy egg containing products, we indirectly support the slaughter of chickens.

I described these processes using words and images, but we cannot truly understand them until we see them firsthand. The documentary Dominion shows the process of raising and slaughtering animals, primarily in Australia. The documentary is available for free on YouTube. If you watch this documentary from the 23 to the 41 minute marks, you can see the processes described for chickens. This documentary shows some extreme examples, but it in general it shows many common practices. Watching these scenes can make us feel uncomfortable. However, if we want to make informed choices about consuming eggs and chicken, and we can tolerate watching this content, then witnessing how they are made with our own eyes is an important step.

It is important to reflect on our actions, values, thoughts, and feelings. How did you feel when you read or watched this content? Why did you feel that way? Did you already know about these processes? Or were you surprised? How would we feel if we raised and slaughtered our pets like this? How would you feel if you were in their situation? Of course, humans and chickens are different. However, chickens have demonstrated complex cognition, are able to communicate, are self aware, can recognize others, can solve simple logical problems, can count simple numbers, can feel emotions, and have unique personalities.5,29 Moreover, chickens can feel pain and distress. In one experiment, after spending time with chickens and attempting to train them, people were more likely to agree that chickens are intelligent, have a unique personality, and can experience boredom, irritability, and happiness.30 If we too spent time with chickens and tried to understand them, we would probably not underestimate them as much. They are not “just chickens”, but sentient beings.

While you are reading this, chickens are experiencing these things. Ducks, turkeys, and other poultry are also going through similar processes. Every time we buy food containing chicken or eggs, we vote with our money for chickens to go through this. Can we justify continuing to consume chicken and eggs if we have the opportunity to live without them?

Chicken and eggs contain protein and other important micronutrients. However, we can get those nutrients from a variety of plant-based foods. For example, tofu and legumes are high in protein.31 I will talk about plant-based nutrition in more detail in future posts. In addition, there are many plant-based chicken and egg substitutes these days. Of course, there are tasty alternatives as well as not so tasty ones. There are unhealthy alternatives as well as healthy ones. There are expensive substitutes and there are cheap substitutes. Depending on our desires and goals, we can find alternatives that suit us. The choice to eat chicken and eggs is also intertwined with other complex factors besides animal welfare. For example, there are also environmental, economic, psychological, and cultural factors that should be considered. I will also talk about these factors in future posts. If you would like to learn about how pork or beef and dairy are produced, you can read more about it in the linked posts.


References

1.            Bennett CE, Thomas R, Williams M, et al. The broiler chicken as a signal of a human reconfigured biosphere. Royal Society open science. 2018;5(12):180325.
2.            Food and Agricultural Organization (FAO). FAOSTAT: Crops and livestock products. 2023; https://www.fao.org/faostat/en/#data/QCL.
3.            Harwatt H. Including animal to plant protein shifts in climate change mitigation policy: a proposed three-step strategy. Climate Policy. 2019;19(5):533-541.
4.            Zuidhof MJ, Schneider BL, Carney VL, Korver DR, Robinson FE. Growth, efficiency, and yield of commercial broilers from 1957, 1978, and 2005. Poultry Science. 2014;93(12):2970-2982.
5.            Smith CL, Johnson J. The chicken challenge: what contemporary studies of fowl mean for science and ethics. Between the Species:. 2012;15(1).
6.            Farm Transparency Project. 2023; https://www.farmtransparency.org/.
7.            Baker BI, Torrey S, Widowski TM, et al. Evaluation of carbon dioxide induction methods for the euthanasia of day-old cull broiler chicks. Poultry Science. 2019;98(5):2043-2053.
8.            Farm Transparency Project. Dominion. 2018; https://www.youtube.com/watch?v=LQRAfJyEsko.
9.            Anthis JR. US Factory Farming Estimates. 2019; https://www.sentienceinstitute.org/us-factory-farming-estimates.
10.         United States Department of Agriculture (USDA). Census of Agriculture. 2017; https://www.nass.usda.gov/Publications/AgCensus/2017/Full_Report/Volume_1,_Chapter_1_US/usv1.pdf.
11.         The Humane Society of the United States. An HSUS Report: The Welfare of Animals in the Chicken Industry. 2013.
12.         Royal Society for the Prevention of Cruelty to Animals (RSPCA). RSPCA Approved Farming Scheme Standards: Meat Chickens. 2020.
13.         Barnett JL, Edge, M.E., Thomson, L., Mackenzie, M., Sansom, G. Kite, V. National Animal Welfare Standards for the Chicken Meat Industry. 2008.
14.         Farm Animal Welfare Council. Report on the Welfare of Farmed Animals at Slaughter or Killing Part 2: White Meat Animals. 2009.
15.         Royal Society for the Prevention of Cruelty to Animals (RSPCA). RSPCA Approved Farming Scheme Standards Information Notes: Meat Chickens. 2019.
16.         Jacobs L, Delezie E, Duchateau L, Goethals K, Tuyttens FA. Impact of the separate pre-slaughter stages on broiler chicken welfare. Poultry Science. 2017;96(2):266-273.
17.         Caffrey N, Dohoo I, Cockram M. Factors affecting mortality risk during transportation of broiler chickens for slaughter in Atlantic Canada. Preventive veterinary medicine. 2017;147:199-208.
18.         Berg C, Raj M. A review of different stunning methods for poultry—Animal welfare aspects (stunning methods for poultry). Animals. 2015;5(4):1207-1219.
19.         Romanov MN, Weigend S. Analysis of genetic relationships between various populations of domestic and jungle fowl using microsatellite markers. Poultry science. 2001;80(8):1057-1063.
20.         Riber AB, Casey-Trott TM, Herskin MS. The influence of keel bone damage on welfare of laying hens. Frontiers in veterinary science. 2018;5:6.
21.         Thøfner IC, Dahl J, Christensen JP. Keel bone fractures in Danish laying hens: Prevalence and risk factors. Plos one. 2021;16(8):e0256105.
22.         Toscano MJ, Dunn IC, Christensen J-P, Petow S, Kittelsen K, Ulrich R. Explanations for keel bone fractures in laying hens: are there explanations in addition to elevated egg production? Poultry Science. 2020;99(9):4183-4194.
23.         Cleveland DA, Gee Q, Horn A, Weichert L, Blancho M. How many chickens does it take to make an egg? Animal welfare and environmental benefits of replacing eggs with plant foods at the University of California, and beyond. Agriculture and Human Values. 2021;38(1):157-174.
24.         Vogel G. ‘Ethical’eggs could save day-old chicks from slaughter. In: American Association for the Advancement of Science; 2019.
25.         New South Wales Government Food Authority. Free range. 2018; https://www.foodauthority.nsw.gov.au/food-labelling/understanding-claims/free-range#:~:text=The%20new%20information%20standard%2C%20registered,hours%20during%20the%20laying%20cycle.
26.         Glatz P. Beak trimming methods-review. Asian-Australasian Journal of Animal Sciences. 2000;13(11):1619-1637.
27.         Royal Society for the Prevention of Cruelty to Animals (RSPCA). RSPCA Approved Farming Scheme Standards: Layer Hens. 2015.
28.         Bell DD. Historical and current molting practices in the U.S. table egg industry. Poultry Science. 2003;82(6):965-970.
29.         Marino L. Thinking chickens: a review of cognition, emotion, and behavior in the domestic chicken. Animal Cognition. 2017;20(2):127-147.
30.         Hazel SJ, O’Dwyer L, Ryan T. “Chickens are a lot smarter than I originally thought”: changes in student attitudes to chickens following a chicken training class. Animals. 2015;5(3):821-837.
31.         Bergeron N, Chiu S, Williams PT, S MK, Krauss RM. Effects of red meat, white meat, and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomized controlled trial. The American journal of clinical nutrition. 2019;110(1):24-33.

Enter your email below to stay up to date with the latest posts:

By subscribing you agree to receive emails from The Elephant On Our Plates and agree with our Privacy Statement. You can unsubscribe at any time.

Enter your email below to stay up to date with the latest posts:

By subscribing you agree to receive emails from The Elephant On Our Plates and agree with our Privacy Statement. You can unsubscribe at any time.