Industrial Animal Agriculture &
Farmed Animals’ Welfare

Layer Hens

A “layer hen” is a female chicken specifically raised for the purpose of laying eggs. These hens are selectively bred to be prolific egg producers and are typically raised in commercial poultry farms or backyard settings. The term "layer" signifies their primary function, which is the production of eggs for human consumption. Layer hens are distinct from broiler chickens, which are bred and raised for meat production.

A layer hen. Credit: Brianna Tucker, Unsplash.

Selective breeding

Wild chickens produce around 12 eggs a year. Over decades of selective breeding, the laying hens on today’s farms have been bred for very high production of eggs, and can lay around 300 eggs per year. As a result of having such hyperactive reproductive systems, modern layer hens can suffer from stuck eggs, reproductive tract infections, cancer, and other illnesses and ailments.

Housing: Battery cages

The most commonly used type of housing for layer hens in industrialised farming systems are small cages known as “battery cages.” These cages are called “battery cages” because the arrangement of rows and columns of identical cages connected, in a unit, resembles an artillery battery. This arrangement, with cages lined up horizontally and vertically, means that as many hens as possible can be kept in as small a space as possible.

Battery cages are small, and between 5-10 birds are typically kept in one cage. Each hen typically has a personal floor space smaller in size than an A4 piece of paper. Battery cages usually have wire sides and bases, so that waste falls through to collection troughs below. The floors of battery cages are sloped so that eggs roll down toward the troughs on one end of the cage, where the eggs are then carried away on a conveyor belt. To access food, birds usually have to push their heads and necks through the wire mesh to access a feeding trough. This can result in their feathers being rubbed off due to the friction.

Hens crammed into small cages on an intensive egg farm in Bali, Indonesia. Credit: Seb Alex, We Animals Media.

An intensive egg farm in Thailand.
Credit: Sinergia Animal.

Welfare concerns for layer hens in battery cages

Being confined in such a small space undoubtedly results in poor welfare for the hens. Hens cannot engage in natural behaviours such as foraging, nesting, perching and dust bathing. They cannot exercise at all, or even fully extend their wings. Caged hens, surrounded by hundreds or thousands of other individuals, with no chance of escape, suffer from high stress levels. Frustration among and aggression betweens hens is common. High stress levels can cause hens to lose their feathers, as can feather-pecking behaviour from other hens.

Layer hens in battery cages who have lost their feathers through stress and/or feather-pecking behaviour.
Credit: Andrew Skowron, We Animals Media.

Physical mutilation of layer hens

In anticipation of probable aggression and feather-pecking behaviour among hens in battery cages, producers routinely conduct beak-trimming on chicks - a process by which one-quarter to one-third of the upper beak or both upper and lower beaks of a bird is removed, often using a hot blade. Beak trimming can cause pain and stress, and can result in reduced sensitivity and impaired function of the beak, which can affect the bird’s overall pecking behaviour.

A layer hen in a battery cage who has had part of her beak removed in a process called "beak-trimming".
Credit Jo-Anne McArthur We Animals Media.

Induction of moulting

Moulting in birds is a natural physiological process which involves the periodic shedding and replacement of feathers, as well as the cessation of egg laying. The bird's reproductive system “re-sets” ready for the next laying cycle.

In nature, this happens seasonally. In an artificial indoor environment, with constant lighting and temperature, the birds do not receive the cues to moult from their environment. Therefore, moulting needs to be induced artificially on CAFOs. This can be done by depriving the hens of food completely, or severely restricting the amount and type of food offered for up to two weeks. This causes the hens to lose a huge amount of weight and shed their feathers. This effectively “re-sets” their egg-laying cycle, and they can start producing eggs again once they receive food. Depriving the hens of food undoubtedly causes them distress, and can also trigger aggressive behaviour towards other hens. The practice of induced moulting using food deprivation has been banned in the European Union and India, but continues elsewhere.

Lifespan of layer hens on a CAFO

On average, a layer hen’s productivity (the number of eggs she lays) starts to decline after around 12 months of laying. At this age, most laying hens farmed commercially are sent for slaughter (note that a chicken can naturally live for around 6 years).

Maceration of unwanted chicks

When discussing the egg industry, it’s important to note that the breeding of young birds to replace “spent” hens generates male chicks as well as females. These chicks are regarded as a “waste product” of the egg industry, and it is common practice to kill them using crude, low-cost methods. This often involves placing chicks, alive and fully conscious, into a machine that grinds them up - a process known as maceration. Another cheap way to dispose of male chicks is to suffocate them, or kill them by gassing.

Further Reading