Light is essential for living

Around us on the earth is an enormous magnetic field, only a part of it can be seen by us human beings and we see this as light.

Light as visible electromagnetic radiation

Light is

  • The name given to visible electromagnetic radiation.
  • It’s also been considered to be a combination of radiation and the reaction on it.
  • Ergo the light experience is depending on the receivers physics as well.

Birds in general have a well-developed eyesight in contradiction with pigs who have very low eyesight (only dark and light) but a very good developed smelling sense. Birds must be able to see small insects and seeds to feed themselves.

In the eyes of living creatures there are cones and rods. Cones are responsible for seeing frequency (colours) and the rods for movements. In general a bird would eat a bright coloured insect it prefers a red one. Chicken communicate partly with their eyesight they observe the other chicken of the group, when one of the found food the other ones will follow directly. So for the social structure light is also necessary. Insufficient light may cause unwanted picking and /or cannibalism.

Light synchronizes several physiological process in the body, such as the eating, digesting and the regulating of the body temperature. Light influences the different hormone processes who are responsible for the growth, de maturity development and the reproduction processes.

There are different types of cones and rods in the eyes of every living creature. Human beings have 3 different kind of cones and birds have 4! Chicken can see between 350 till 800 nm., human beings can only see between 400 and 750 nm. Next to the different perspective’s with their eyes they also have receptors in their brains which also influence a large number of biologic and physiologies’ functions These receptors are “picking up” especially the longer wave lengths, which influence the reproduction processes, social behaviour but also so the 24 hour rhythm is influenced by these receptors.

So the perspective of “light” is completely different than for human beings as well!!

Eye anatomic
Eye anatomic

 The blue line is what chicken see and the green line is how human beings see it
 The blue line is what chicken see and the green line is how human beings see it!

The influence of light in poultry houses has been an item for research for many years and still is!

Research discovered a difference in perception of light

(source: Poultry Science 1999-78 & 1997-76)

Wavelength Band (nm) Human colour sensation Human perception at 0.1 w/m²(lux) Fowl perception at 0.1 w/m²(gallilux) Times
440-460 Blue 3,0 39,8 13,3
460-480 Blue 7,1 52,4 7,34
480-500 Blue 16,4 53,1 3,24
520-540 Green 60,2 59,0 0,98
540-560 Green 67,8 66,9 0,99
620-640 Orange/Red 16,7 42,7 2,56
640-660 Red 6,6 20,7 3,12
680-700 Red 0,5 5,8 11,30



  1. Light is next to water, food, ventilation and heat the most important factor in a modern poultry house! With the right light the farmer can achieve better results!
  2. The needs for light are different for different animals and for different ages.

Basic demands for light in a poultry house

As the needs of animals change with age and what one wants to do with the animals, it leads to different lighting solutions for different applications. Some general characteristics are:


  • Uniformity of light intensity at animal level
  • Starting with a higher light intensity to stimulate the development of the growing process and then being able to reduce the light intensity to the needs of the animals
  • Light reflecting on water drops hanging on nipple drinkers helps to attract the young chicken to the drinker so they find water faster!

Rearing Houses for future Layers and Parent Stock

  • Generally like the broiler houses but more and more light management is used for training the pullets to prepare them for the production period later on.


  • Light uniformity in most of the poultry house, especially in the feed troughs, although we prefer less light intensity where we want the egg laying done and sometimes we increase light intensity where we don’t want any egg laying.

Parent Stock

  • Light uniformity in most of the poultry house although we prefer less light intensity in the places where we want the egg-laying done.
  • A higher light intensity compared to layer house to stimulate the males to do the mating.

Examples of light plans

Can be found under the heading (tab) examples of light plans.

Light intensity

As mentioned, to provide the right light intensity is important and in general the breeding companies, the companies that provide the animals, know their animals best. Much information on this subject can be found on their respective websites and in their technical manuals.

Calculating Light Intensity

The challenge with Light Intensity is that whereas the Light Output of a lamp is given in Lumen, most farmers are interested in the Lux level near the animals. The manufactures of lamps are obliged to mention the light output in LUMEN per lamp. People looking into this will find values from about 10Lumen/Watt to over 150Lumen/Watt. However knowing the Lumen Output is one thing, getting a good indication of the Lux Level with the animals is another.

We know that some people use as a rule of thumb: one lux equals one lumen / m². Please be very careful with that. Just check it yourself: installing a lamp 50cm higher makes a significant difference in Lux level on the ground .

Gasolec B.V. calculates the LUX level near the animals on the ground for Gasolec Orion and Gasolec IPL Light Systems in the following way:

Light formula

The correction factor is being used to reflect factors that influence the light intensity like the reflection of the walls & roof & floor, the height of the lamps, the dust in the air, the type & colour of the birds, etc. Generally this correction factor can be anywhere between 0.35 and 0.60 depending on the above variables. This formula will change for LED Lamps.

Light hours per day

This is again an important subject and scientists as well as farmers as well as the animal welfare groups have different view on it! As a start we refer to the different suppliers of the animals and their technical manuals.

In general the light must be switched off at least 4-6 hours / day except for the day-old-chickens during their first days, where 24 hours of light a day is most common.

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