From cage to aviary: How lighting helps

In an increasing amount of countries, a shift away from cage housing systems is becoming inevitable due to animal welfare regulations.

Aviary systems are considered to be the best alternative for cage systems. What they all have in common is that they are multi-tier systems that allow hens to move around freely throughout the house. Although this aims to improve animal well-being, it also comes with several challenges.

With over 10 years of experience in aviary lighting, we know how lighting can help to overcome these challenges.

The challenges of switching from cage- to aviary housing

Feather pecking

When feather pecking occurs, hens peck at the feathers of other hens, sometimes pulling the feathers out and eating them. It often occurs when they feel uncomfortable or stressed.

In cage houses, freedom to move is limited. Because of this, the hens are only able to interact with the other hens in their cage. In aviary systems, the hens have more room to move around, behave naturally and interact with all the other hens in the house. This increases the risk of pecking.

Feather pecking increases the amount of injuries and wounds. Since the red colour of blood and wounds further triggers pecking, it can even lead to cannibalism. Altogether, pecking decreases animal welfare and increases injuries & mortality rates.

Floor eggs

Floor eggs (2) can also be a serious problem. These are eggs that are laid outside the nesting area.

In cage housing systems, the hens have no other option than to lay their eggs in the nests inside their cages. However, as the hens are able to walk around freely in aviary systems, they can lay eggs wherever they want. This leads to a higher amount of floor eggs.

Floor eggs are considered to be second grade eggs, which are not as hygienic as eggs laid in the nesting place. Besides that, they have to be collected by hand, which costs more time. As a result, floor eggs decrease revenues and increase labour costs.

How can lighting help?

Now that we’ve had a look at the challenges that come with switching from cage- to aviary housing, let’s have a look at how lighting can help in overcoming them.

Reduce feather pecking

1. Reduce stress
One of the main causes of feather pecking is stress. A lower amount of stress decreases pecking. Optimal lighting reduces stress by:

• Being flicker-free. Flickering lights increase stress. 100% flicker-free lighting is therefore highly recommended.
• Enabling deep and equal dimming. By making use of lights that dim both deeply and equally from 100-0%, the lights can simulate natural dusk and dawn. This simulation rather than a sudden change in light intensity will significantly decrease stress.
• Providing a broad light spectrum. A broad light spectrum improves the hen’s sight. By improving their sight, the hens become calmer. Besides that, better sight will improve their social interactions with other hens and their movement through the house. This eventually reduces stress as well.

2. Camouflage blood & wounds
Another way in which lighting can reduce pecking is by camouflaging blood and wounds. When pecking occurs, it is useful to mix white light with red light or even use red light monochromatically in extreme cases of pecking. Amongst others, this will camouflage the redness of the blood and wounds at which the hens are pecking. This way they are less noticeable by the hens, which reduces pecking.

CORAX	BUBO	ARA
Main lighting	System lighting	Perch lighting

Less floor eggs and stimulated feed and water intake

1. Stimulate desired behaviour

By stimulating desired behaviour, floor eggs can be reduced. There’s more though. Even feed and water intake can be stimulated. An optimal light distribution and the correct light intensity play a key role here. How? By providing the right amount of light at the right place, desired behaviour can be stimulated.

Now, what does this look like in practice?

• Less floor eggs by making sure the nests are darker than the activity areas and by ensuring uniform light distribution below the system as well as in the aisles, the hens are encouraged to lay their eggs in the nests. Result: less floor eggs
• Stimulated feed- and water intake by making sure the feeding- and drinking areas are well-lit, feed and water areas can be found more easily. This way, feed- and water intake are increased.

Improving life through brightness

Time to wrap it up. A switch from cage- to aviary housing is becoming increasingly inevitable. Because of the fact that hens can move around freely in aviary systems, several challenges occur. Luckily, lighting can help. Feather pecking and floor eggs can be reduced, plus lighting is even able to stimulate feed and water intake?