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Cage housing to aviary housing: lighting helps!

News - placed on 11/07/2018

Located in the Netherlands since 1974, HATO Agricultural Lighting is one of the world's major producers of agricultural lighting solutions. HATO’s innovative lighting solutions focus on animal welfare and performance. A correct light climate is an essential aspect of proper housing equipment.

Animal welfare is gaining in importance, which is why the transition from cage housing to aviary housing is becoming increasingly inevitable. There are various factors driving this transition.




The transition from cage housing to aviary housing. Why?



In 2012, the EU implemented a directive that prohibits traditional cage housing systems. Enriched cages and alternative systems remained in use. This legislation is being increasingly implemented throughout Spain.



In addition, animal welfare activists are fully opposed to cage housing and have even managed to convince certain large retail chains such as Lidl to stop selling their code 3 eggs (which are produced in cages). Consequently, these chains will switch to type 2 eggs (produced in barns, but not cages), type 1 eggs (produced free range) or type 0 eggs (produced organically).



In conclusion, changing from (traditional) cage housing to aviary housing is becoming inevitable.




Traditional cage housing vs. aviary housing

Traditional cage systems are designed to use multiple tiers of cages which house 3-5 hens per cage. The chickens are confined to their cages, thus creating room for more tiers of cages. This allows farmers to use the space in their houses as efficiently as possible. Below the cages is a slope so the eggs can roll to the bottom of the house where the eggs are either collected by hand or transported by conveyor belts.


The aviary system is considered to be the best alternative for cage systems. It allows large flocks to be housed, enabling large scale egg production to ensure optimal performance. There are several kinds of aviary systems. A fact is that it remains a multi-tier system that allows hens to move freely throughout the house.  The hens can move across several tiers, all with different purposes:


  • Inside the aviary:  perches, feeding area and nesting area
  • In between and below the systems: litter / activity area


The system makes it possible for layers to behave naturally; they can scratch, dust bath, peck on the ground and more. The eggs that are laid in the nests are collected and transported by conveyor belts to the bottom of the house. Image 1 shows a typical set-up of an aviary system.


The consequences of switching to aviary housing

Since the hens are free to move around in the aviary house, several problems may occur.


One of these problems is feather pecking. When this occurs, hens peck at the feathers of other hens, sometimes pulling the feathers out and eating them. Feather pecking occurs when layers feel uncomfortable or stressed. Feather pecking increases the risk of injuries and may trigger cannibalism. This will lower welfare levels, increase the incidence of injuries and may cause higher mortality rates.


Another problem is cloaca or prolapse pecking. When an egg is being laid, the hen’s oviduct turns inside out to lay a clean egg without faecal contamination. At that moment it appears red and other hens may respond to this colour by pecking the cloaca. Sometimes the oviduct fails to return to the proper position after the egg has been laid; this is known as prolapse. Due to the red and shiny colour of the oviduct, other hens will notice the prolapse and start pecking it. As with feather pecking, cloaca and prolapse pecking increase injuries, may trigger cannibalism and may eventually increase mortality rates.



Floor eggs can also be a serious problem. As the hens are free to walk around, they can lay eggs wherever they want, instead of being forced to lay their eggs in cages, where they can be automatically transported. This increases the risk of floor eggs. These eggs are considered to be second grade eggs which are not as hygienic as eggs laid in the correct nesting place. In addition, floor eggs have to be collected manually, which significantly increases labour costs.




Lighting as the solution!


Stress is one of the reasons for feather and cloaca pecking. Lighting can prevent stress in several ways:


  • Flicker-free lighting is important. Flickering lights are one of the major causes of stress. When a light flickers, the chicken has the feeling that a predator bird is hovering above it. As this is perceived as a potential threat, the chickens experience continuous stress under flickering lights. 100% flicker-free lighting is highly recommended to reduce stress.
  • By making use of lights that dim deeply and equally from 100-0%, the lights can naturally simulate dusk and dawn. This natural simulation instead of a sudden change in light output will significantly decrease stress.
  • To ensure optimal hen vision, a proper broad light spectrum is very important. By improving the hen’s vision, social interactions with others and movements through the house will improve. This will eventually reduce stress levels.


Another way in which lighting can help in reducing pecking is by making use of colours. When feather and/or cloaca pecking occurs, it is useful to turn the lights to red. This will camouflage the redness of the oviduct and/or blood. Dimming the light may also contribute to reducing these problems.


By ensuring that photostimulation doesn’t occur too early, prolapses can be prevented. It’s important to make sure the hens are at the right age and weight before starting photo stimulation.


Uniform light distribution will contribute to uniform weight. Consequently, fewer pullets will lag behind in growth, preventing problems during photostimulation. Uniformity of light will also contribute to a uniform start of lay.




Even light distribution, combined with a correct light intensity, prevents bright spots and shadows. This in turn prevents the hens from being triggered to lay eggs outside their nests. Result: a lower number of floor eggs.



By ensuring the feeding and drinking lines are well-lit, the hens will be strongly stimulated to eat and drink. Be aware: there must be a significant difference in light intensity between the feeding area and the nesting area.




Custom-made lighting

It is essential that lighting equipment is adapted to suit the type of birds in the house, the dimensions of the house and the equipment used. The only way to realise an optimal light climate is by taking all these factors into account. For this reason, we offer custom-made light plans. We take everything into account to create a light climate that enhances both animal welfare and performance.


Are you going to switch to an aviary house and are you looking to improve animal welfare and performance? Request a free custom-made lighting plan or a test house by sending an e-mail to sales@hato.lighting.


We are the lighting specialists!



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