Week 7: Do We Need To Eat Eggs?

Eggs may be a source of protein, but are they really needed for a healthy diet? We delve into the reasons why we should end our consumption of eggs, for the chickens, the environment, our health, and the health of others.

About Layer Hens

Society views most animals as one-dimensional, interchangeable units within a species, but this is far from true. Animals exploited for food, clothing, and entertainment, are much more than bodies of flesh or production machines. Here are some facts about chickens that you might not know!

Every hen is unique!

Like humans, every chicken is unique. Research has shown that chickens have different personalities, which impacts the way they respond to stimuli and situations and interact with others. Understanding that animals have personalities helps us see them as the individuals that they are [1]. Rescuers who care for ex-layer hens are always talking about how each hen is different. Some absolutely love attention, cuddles, and pats, while others are more independent and happy to be left alone.    

rescue layer hens eggs
Rescue hens experiencing freedom for the first time.

A hen doesn’t naturally produce 300 eggs

The ancestor of the modern-day layer hen, the Red Jungle Fowl, only lays 10-20 eggs a year [2]! This is a stark contrast to layer hens, who produce around 300 eggs in the same time frame [3]. Selective breeding, artificial lighting, feed control has created this unnatural amount, which is terrible for the hens. An eggshell is made almost entirely of calcium and an overproduction results in a calcium deficiency for hens. This deficiency can cause osteoporosis, making them prone to bone fractures [3]. Approximately 56% of battery hens suffer from painful fractures.

Chickens eat their eggs

Chickens will sometimes choose to eat their own eggs, as they contain vital nutrients for their health, like calcium, and because they like the taste. If left alone with their eggs, they will break them open and eat the insides and shells [4]. Rescuers have said that the hens get very excited when they can eat their eggs. The industry obviously denies them from eating the eggs, as it reduces the amount they can sell to the public.

To learn more facts about chickens, please see the blog Are chickens really meant for eating?

The Industry

There are more than 7 billion layer hens around the world [5]. If each hen produces 300 eggs, it means there are around 2,100,000,000,000 (2 trillion 100 billion) eggs produced a year. People consume eggs on their own or in products, like muffins and cakes, while millions are also used in vaccinations. On average, a person consumes around 200 eggs per year [6]. In order to meet consumer demands, chickens around the world are raised in appalling conditions and undergo routine mistreatment. 


Farming eggs is pretty standard around the world, using three types of egg production systems, caged, cage-free, and free-range [7]. Farms typically hold 20,000-100,000 hens, however, smaller “family” farms may have up to 1,000. All systems cause hens stress, due to boredom and frustration from confinement and an inability to establish a social hierarchy. This stress can create problems such as cannibalism, bullying, and feather pecking. Providing enrichment, like on free-range farms, does not always solve this problem. Hens are then competing for the same perches and nesting boxes, which can make them more aggressive towards one another [8].


Globally, 86% of layer hens are kept in cages, meaning they are unable to exhibit their natural behaviours [7]. Each shed contains parallel rows of tiers of cages. A single shed can hold up to 100,000 individuals [9]. The standard battery cage holds between 4-6 hens, while newer “enriched” cages hold between 60-100 hens. These are not common in Australia. Although cage sizes can vary, all types give a hen the space of an A4 piece of paper. 

caged eggs layer hens
Inside an Australian caged shed.
Credit: Animal Liberation.

Hens in a cage system can never stretch their wings, dust bathe, explore, or forage. They will also never stand on solid ground, as the cages have sloped wire floors, allowing the eggs to roll out and their waste to be collected on a conveyor belt below them [7]. The wire floor often causes hens to develop toe pad hyperkeratosis, which is where the skin on their feet thickens and they have deep, open sores and swelling. 

battery cage floors layer hens eggs
Wire floors inside a cage.
Credit: Animal Liberation.

Cage-free or Barn Laid

A cage-free farm means that hens live inside a shed with up to 30,000 others. They may be given nesting boxes and perches, which allows them to exhibit some of their natural behaviours. While this housing system does allow the birds to walk around, it still treats them as machines. Like in the cages, the floor is most often not solid, so that the sheds do not have to be cleaned as their waste falls below them [7].

cage free eggs layer hens
Inside an Australian cage-free shed.
Credit: Animal Liberation.


Free-range systems are the same as cage-free, however, the hens are sometimes allowed to go outside during daylight hours [7]. Unfortunately, the sheds are so crowded that it can be impossible for all of the hens to make it outside. 

free range eggs
Free-range shed doors.

Breeder flocks

Hens and roosters used for producing fertile eggs live in sheds with litter or wire mesh flooring. After 12 months of being confined to the sheds, they are killed due to a decrease in productivity. The sheds are cleaned after the birds are removed, meaning they live in their waste for the entire period [10 PDF].

Australian Standards

In June 2019, Australia had 20,946,659 layer hens, who produce over 6.22 billion eggs for human consumption. There are also an additional 7,659,331 pullets, who are female chicks waiting to enter the system once they are able to produce eggs [11].

Mass Culling Male Chicks

Male chicks are killed on their first day of life, as they are deemed ‘useless’ by the egg industry. Males have no purpose, as they cannot lay eggs and do not grow large enough to become meat. They are either ground up alive in a macerator, suffocated to death, or gassed to death [12]. All methods are incredibly cruel, however, some take over a minute to die from asphyxiation during gassing and suffocation. All egg purchases support the killing of male chicks. Approximately 6 billion males are killed every year around the world [13]

Animal Liberation exposed this on Australian farms in 2016.


Boredom, frustration, competition, and an inability to establish a proper social hierarchy can result in increased aggression and pecking towards one another. Instead of reducing flock numbers, increasing enrichment, and banning the cage, the industry trims the chicken’s beak, known as debeaking [14 PDF]. A chicken’s beak is a complex sensory organ, with numerous nerve endings, and a cluster of highly sensitive mechanoreceptors in the tip. Their beaks allow them to manipulate food and other objects for nesting, exploring, drinking, preening, and defence [15]. In Australia, most layer hens have the tip of their beak seared off by a hot blade. This procedure is incredibly painful, leaving many birds with chronic pain and traumatic-neuromas [16 PDF]. Hens tuck their bill under their wings and lessen the amount of pecking and preening they do, and exhibit behaviour changes months after the procedure [15].

Killed at 18 months old

Naturally, a hen can live for up to 12 years, but on egg farms, they are only kept alive for 18 months. After just 12 months of laying, a layer-hens egg production rate slows, making them no longer economically viable. As a result, the industry considers them ‘spent’ and they are sent to slaughter. Removing hens from the cages and sheds is known as ‘depopulation’ [17].

On a cage egg farm, the workers are known as ‘rippers’ because of the way they roughly remove the hens from their cages. On a cage-free or free-range farm, workers are called ‘catchers’. In both situations, workers are allowed to carry up to 5 birds in each hand, often by their fragile legs. The birds are then placed into a trolley or crate, depending on the slaughter method.

Due to the high amount of eggs laid and lack of exercise, layer hens have poor bone health, and the process of depopulation results in broken legs and snapped wings [18]. A UK study found that 30% of layer hens arrive at the slaughterhouse with broken bones due to rough handling [19]

Layer hens are either gassed to death or sent to a slaughterhouse where they will have their throats slit, like broiler chickens [20]. Due to their poor health and small weight, their bodies are considered low-quality. As a result, their remains are used for pet food or in lower-quality products for humans, like stocks and soups [21].

Forced Moulting

Some farmers may try to prolong their flocks’ ability to produce eggs with ‘forced moulting’. This is achieved by withdrawing feed for two weeks or providing them with low-quality feed to reduce their body weight because it reinvigorates egg production. Forced moulting is incredibly cruel for the hens [21].

The Environment

Egg production is having an impact on the environment, in terms of land use, resources, waste and pollution. From an environmental perspective, switching to plant-based foods will reduce the amount of land we need to clear for food crops, as well as pollution, waste, water use, and will eliminate animal feed.


Although it is great that consumers are switching their demand for caged eggs to free-range, it would be impossible to raise all 7+ billion hens with enough space to exhibit natural behaviours, on free-range farms. The amount of land required for them would cause more land clearing, a decline in wildlife populations, and increased pollution. Currently, with approximately 86% of hens in cages, a kilogram of eggs needs 6.27 square meters of land. By looking at broiler chickens, we can gain a little more insight into how much land would be needed, as they are all raised inside sheds. Per kilogram of meat, broilers need 12.22 square meters. Keep in mind broiler chickens are predominately raised in sheds without much room to move and no enrichment [22]

land use per 100 grams of protein


It will always be more efficient to use the feed and water for human consumption than give it to an animal who will then be slaughtered. It takes approximately 2.3 kilograms of food and 578 litres of freshwater to produce just one kilogram of eggs [23]. If we break this down per 100 grams of protein, they require 521 litres of freshwater! This differs greatly from plant-based foods, like tofu, which requires 149 litres per kilogram or 93 litres per 100 grams of protein [24].

The amount of food and water chickens need changes depending on the housing system. Chickens kept in cages are unable to exercise and thus require less food than those in sheds or on free-range farms. Chickens in sheds need approximately 14% more food, free-range need about 18% more, and organic require roughly 20% more [25]. The increase in food means that the land required per kilogram of eggs will also increase.

layer hens cage eggs
Layer hens on Australian caged egg farm.
Credit: Animals Uncovered

Waste and Pollution

Waste from an egg farm includes dead birds, faecal matter, chemicals and medication, unusable eggs, water, feed, feathers, as well as plastic, cardboard, gloves, and other general waste [26 PDF, 27 PDF]. Dead birds are often sent to a rendering plant to become food for farmed animals, like chickens, pigs, ducks, and fish [26 PDF]. Other organic waste from caged farms is collected and processed off-site and is regularly used in agriculture. While crops do need fertilizer, the amount of organic waste used can pollute the environment. Other farms may burn or bury the litter. Inorganic waste, like plastic and gloves, are sent to landfill.

When organic waste is stored on-site, there is a chance that nutrients will be exported with surface water runoff, meaning it can spread into surrounding water bodies and cause eutrophication. This can promote the growth of algae or create high nitrate levels, which are toxic to wildlife and humans. Nutrients can also leach into the soil contaminating groundwater. The excess nutrients and salts affect the soil profile and impact plant growth and the environment [26 PDF]. Per kilogram of eggs, approximately 21.76 grams of excess nutrients enter the surrounding environment, while soy releases just 6.16 grams [28].

When analysing the production of greenhouse gases across the supply chain of various foods, plant-based products on average, produce 10-50 times less than most animal products. The production of eggs produces 4.5 kilograms of CO2 per kilogram of eggs [29] or 4.21 kilograms of CO2 per 100 grams of protein. In contrast, tofu produces 1.98 kilograms and pees just 0.44 kilograms per 100 grams of protein [30]

Waste on underneath the cages.
Credit: Animal Liberation

Health Impacts

Your Health

There is a lot of contradicting information regarding the effects of eating eggs on our health. Some research suggests that eggs increase our risk of heart disease due to their cholesterol and saturated fat content, while others say it reduces our chances – making it difficult for us to know who to trust. Basically, our bodies naturally produce all the cholesterol that we need, meaning there is no need for us to eat additional amounts. When there is too much cholesterol in your blood, it builds up the walls of our arteries and can cause a form of heart disease, known as atherosclerosis. As the arteries become narrowed, blood flow to the heart is slowed or blocked [31]. While more research is needed, studies have also suggested a link between the consumption of eggs and hormone-sensitive cancers, like prostate, breast, and ovarian cancer [32, 33, 34].

Additionally, eggs are considered one of the most bacteria-filled foods you can eat, as they are laced with salmonella. While cooking can get rid of salmonella, there is a chance that some bacteria will remain, causing bacterial infections or food poisoning [40].

As eggs are the highest cholesterol-containing foods and have a possible chance to increasing cancer risks, our advice is to avoid it, especially when you can get all of the same nutrients from plant-based foods that don’t contain cholesterol. Another benefit of eating plants is that they contain high amounts of fibre, which is necessary for healthy digestion!

ProteinLegumes (soybeans, tempeh, lentils, tofu, kidney beans, chickpeeas, lima beans), peas, quinoa, oats, spinach, mycoprotein, seitan, peanut butter, wholewheat, flaxseeds, nuts and seeds (almonds, walnuts, hemp seeds, artichokes, buckwheat, chia, pumpkin seeds, hazelnuts, cashews), dark-coloured greens (kale, broccoli). [35, 36]

*too much choline can be damaging and eggs are the richest source
Broccoli, Brussels sprouts,  brown rice, chickpeas, lentils, tofu. [37]
LuteinSpinach, kale, mustard greens, collards, green peas, summer squash, brussels sprouts, broccoli, and yellow carrots
Vitamin D (only hens who have access to outdoors eggs contain vitamin d)Sunshine!, mushrooms (tip, leave your mushrooms in the sun before cooking them for extra vitamin d boost), fortified soy milk, fortified orange juice, fortified almond milk, fortified tofu.

*even non-vegan items only naturally contain small traces of vitamin D, it is important to eat fortified foods or have regular access to the sun!
FolateLegumes (lentils, chickpeas, kidney beans, pinto beans), peas, asparagus, leafy greens (spinach, kale, rocket), beetroots, citrus fruits (oranges, grapefruits, lemons, limes), Brussels sprouts, broccoli, nuts and seeds (flax, walnuts), bananas, papaya, avocado, fortified grains [38].
Vitamin ABroccoli, carrots, spinach, capsicum, cabbage, sweet potato, kale, squash, collards, celery, lettuce, tomato, magnos, grapefruits, cantaloupe, apricots, watermelon, passionfruit, blueberries, pistachios, black-eyed peas, paprika, tofu [39]

Public Health

As we discussed in our blog about broiler chickens, found here, people who work or live near chicken farms are at risk of serious health issues. Poultry farmworkers are exposed to bacterial toxins, dust, and adverse odours, leaving them with the potential to suffer from respiratory reactions, airway irritation, inflammation, decreased lung function, stress, itchy, red, and watery eyes [41, 42, 43]. Workers are also exposed to a high level of noise inside the sheds, which can damage their hearing [44]. People who live near the farms, hatcheries, and slaughterhouses are also at risk due to hazards in the air, water, and soil 

As seen in Melbourne over the last few weeks, workers are also at risk of catching the zoonotic infection – avian bird flu. Zoonotic disease is spread from animal to animal and animal to human. Although bird flu has not yet mutated to be infections from human to human, it is completely possible that it will happen in due time. [45, 44].

What’s Next?

Although it is great to see more people opting for cage-free or free-range eggs, no system is perfect, and all still contribute to the deaths of male chicks, and spent layer hens. Further, buying pre-made products is most likely still supporting caged eggs, as it is cheaper for the companies who produce them. 

The thought of cutting eggs out of your diet might seem a little daunting, but we promise you, it is super easy, thanks to the amazing range of vegan alternatives that are available! We’ve put together a list of egg-free breaky, mains, snacks, and desserts for you, here.

By reducing or ending our demand for eggs, we are saving billions of chickens from a life of misery and death, while protecting the environment, improving your health, and the health of others.