Battery Farms | The Story Behind Your Eggs

Take a close look next time you take a box of eggs from the supermarket shelf. Do you know where or how your eggs were produced? Read on to learn more about battery farming and the story behind your eggs.

Origins of domesticated chickens

The domestic chicken came from the Jungle fowl, originally found in Sri Lanka, India, and southeast Asia. DNA analysis and carbon dating show the creation of the domestic chicken happened around 5,400 years ago, through the selective breeding of red jungle fowl.¹ Now, there are hundreds of different breeds of domestic chicken worldwide.

A wild jungle fowl may produce less than ten eggs per year. Thanks to a particular mutation, domestic egg-laying chickens can lay one per day, all year round. Most egg-laying chickens are slaughtered at around 16 months when production becomes less reliable.² But how did they live up until this point?

What is battery farming?

Early in the 20th century, egg farming became intensive when chickens started being housed in wire cages indoors. This was more efficient - no more predation by roaming predators, droppings fell cleanly through the wire to land in collection trays, and the birds ate food fortified with vitamins to replace those obtained by foraging and sunlight. Controlled temperatures and restricted movement meant food was directly converted into eggs. And huge numbers of chickens were stacked in cages in just one shed. This was battery farming, and it made eggs abundant and cheap.

But in battery farms, hens are packed closely in cages, unable to stretch their limbs. Eventually, a rise in public concern for animal welfare, as well as research, led to a 2012 ban on battery farming in Europe. And this trend is being mirrored elsewhere. Advisory non-profit Egg Farmers of Canada have committed to phasing out battery farming by 2036.³ In the USA, in 2017, several major chains, including McDonalds, Nestle and Subway, announced they would sell products made with only cage-free eggs.⁴

Legislation against battery farms

Battery chickens might be banned in Europe, but there is no ban on caged farming overall. The EU permits enriched cage systems, where the cage must contain a nest, a perch, claw shorteners, litter for pecking and scratching, and 750 cm square of floor space per hen.⁵ These cages allow chickens to carry out some natural behaviours. But many people argue this is still not enough.

Why isn’t all egg farming cage-less?

Caged farming has gained a reputation for being cruel and inhumane. Yet other types of housing - indoor barns and free-range - also show problems. Here are a few reasons why cage-less farms aren’t the simple solution they may seem:

1. Feather pecking: Though this may sound simply annoying, severe feather pecking is a serious issue in hen farming. Birds develop exposed bald spots, injuries, and even cannibalise each other to death. It’s difficult to control in a large, uncaged flock - a study estimated some 65 per cent of UK free-range flocks showed evidence of severe feather pecking.⁶ Research is investigating if pecking props or lighting can reduce hen aggression, but the issue has been studied for years without easy answers.
2. Injury risk: Domestic chickens are comparatively clumsy, heavy birds compared to their sleek jungle relatives. Their keel bones, an extension of the breastbone, are weakened by continuous egg laying, which requires calcium to be directed away from bones to eggshells. Keel bone injuries can occur in about 36 per cent of birds in enriched cages and 86 per cent in free-range systems. Hens naturally want to perch, but injuries can occur when they dismount.⁷ Hen flocks can also crowd, trample and smother each other if frightened.⁸
3. Disease risks: Standing in dirty litter raises the risk of diseases, parasites, and dirty eggs. Droppings from migrating birds can cause avian influenza outbreaks in free-range flocks.⁹
4. Logistical issues: Changing large-scale farming methods takes time and money. Hens that have grown up in cages cannot simply be set loose in another system, and cage-free farming can only accommodate two-thirds or fewer birds by comparison.

Where next for egg farming?

Buying free-range instead of caged eggs can seem an easy option to show support for animal welfare. The price difference is small compared to that of meat, and the mental image of hens living permanently indoors, inside small wire environments, is easy to picture and dislike. The US food chains recognise this, which is why they have declared support for cage-free eggs. (Despite that, only 8 per cent of the 300 million laying hens in the USA are currently cage-free.)¹⁰

According to Dr Victoria Sandilands, a poultry behaviour expert at Scotland’s Rural College, the unanswered question is how to balance people and animal needs while preserving the environment. As Dr Sandilands says, “The advantages of egg production are that eggs are very healthy for you and producing eggs is probably more environmentally friendly than producing some types of meat.” Because of this environmental edge on other proteins, it looks as if eggs are here to stay.