Lighting programme for layers
Light drives lay. First, in rearing, the day is shortened so pullets don’t mature too early; then — at the right age and the right body weight — it’s lengthened to start lay. During production the day is held long and is never shortened. We explain how to build and run a layer lighting programme in a simple way that follows standard management.
verifiedFrom the team that has organised work on poultry farms for years.
A lighting programme is a light-management plan that decides when a flock starts to lay and how long it sustains high production. Hens respond to it through their biological clock: a change in day length is the signal that it’s time to mature and lay eggs. That’s why light is treated as a production tool — as important as feed and water — and a well-built programme helps you get even, persistent lay without forcing the birds.
Why does light rule lay?
Hens are sensitive to day length. A short, decreasing day delays sexual maturity, while a long, increasing day speeds it up and triggers ovulation. The whole programme rests on this: in rearing the day is deliberately kept short, so pullets don’t start laying too early and too light, and at the right moment it’s lengthened (this is photostimulation) so the onset of lay falls evenly across the flock. After that the day stays long, because shortening it during production lowers lay.
How a lighting programme works and what it’s made of
A lighting programme is three phases — rearing, photostimulation and lay — plus light intensity and control over natural light. The key rule: during production the day is lengthened or held, but never shortened.
Rearing: a short, decreasing day
In rearing, pullets are kept on a short or gradually decreasing day, often stepping down toward around 8–10 hours of light. The point is to keep the birds from maturing too early, so they have time to build body weight and frame. Too long a day in rearing rushes maturity and can hurt later persistency of lay and egg size.
Photostimulation: the signal to start
Photostimulation is the lengthening of the day that triggers lay. It’s done when the flock reaches the right age and, above all, the right body weight and uniformity. The day starts to grow in steps, and the flock reads it as “time to lay”. A well-chosen moment gives an even, strong start; too early or with birds too light — weaker persistency and smaller eggs.
Lay: a long day, never shorter
During production the day is held long, usually around 14–16 hours of light. The key rule: during lay you may only lengthen or hold the light — never shorten it, because cutting the day lowers lay. A steady, repeatable daily rhythm matters here just as much as the number of hours.
Light intensity and colour
It’s not only day length that counts, but also light intensity (lux) and how evenly it spreads through the house. Too dark and the birds eat less and are less active; uneven lighting feeds unevenness in the flock. The colour of light (warmer or cooler) affects bird behaviour, which is why modern dimmable LED systems make running a programme easier.
Natural light and the house type
In a window house you have to reckon with daylight — without blackout and light control it’s hard to run a real programme, especially in summer with a long day. A closed house controls light fully: timers, dimmers and LED give full control over day length and intensity regardless of the season.
Free-range, aviary and cages
A lighting programme is run in every housing system — free-range, aviaries and cages. The same phase rules apply in each, but you have to account for access to natural light: on range and in window systems the natural day adds to the programme, so the plan must take that into account.
A layer lighting programme step by step
- 1
Start from the house type and light source
Check whether you have a closed house or a window house, and how lighting is controlled — timers, dimmers, LED. That decides how far you can govern day length and intensity. In a window house plan for blackout or deliberately account for natural light in the programme.
- 2
Keep a short day in rearing
Through rearing keep the day short or gradually decreasing, often around 8–10 hours, so pullets don’t mature too early. The goal of this phase is to build body weight and flock uniformity calmly, not to rush the birds into lay.
- 3
Photostimulate by body weight, not just age
Decide the start by body weight and flock uniformity, not the calendar alone. Lengthen the day only once the birds reach the right condition. Stimulating too early or with pullets too light weakens persistency of lay and gives smaller eggs.
- 4
Lengthen the day in steps
After the start add light gradually, step by step, working up to the long production day, usually around 14–16 hours. Do it evenly and predictably — sudden jumps confuse the flock. Keep the lights-on and lights-off times steady.
- 5
In lay, hold the long day and don’t shorten it
During production hold the long day and remember the iron rule: light may only be lengthened or left unchanged, never shortened. Cutting the day during lay lowers production, so once the long day is set you don’t roll it back.
- 6
Mind intensity and even spread
Set the light intensity so birds can see feed and water well and stay active, and make sure the whole house is evenly lit with no dark corners. Check that the light doesn’t fade over time, and note changes — even light supports even lay.
Frequently asked questions about the layer lighting programme
When should I start photostimulating the flock?add
Don’t look at the calendar alone. Photostimulation — lengthening the day — starts when the flock reaches the right body weight and is well uniform; age is only a guide. Stimulating too early or with pullets too light gives weaker persistency of lay and smaller eggs, so first make sure the birds are in the right condition.
Can the day be shortened during lay?add
No. During production light may only be lengthened or held unchanged — never shortened. Cutting the day during lay lowers production, so once the long day (usually around 14–16 hours) is set you don’t roll it back. It’s one of the basic rules of running a lighting programme.
How much light should layers get during production?add
During lay the day is held long, most often around 14–16 hours of light, but intensity (lux) and even spread through the house matter too. The exact values depend on the bird line and the house type, so it’s best to follow the management guide for your strain and not change settings during production without reason.
Can you run a lighting programme in a window house?add
You can, but it takes control over daylight. Without blackout and light control a natural long summer day will disrupt the programme. A closed house controls light fully — timers, dimmers and LED — regardless of the season, while in a window house you have to deliberately account for the natural day in the plan.
Record your lighting programme in DlaFerm.pl
In DlaFerm.pl you note your lighting-programme settings — the phases, day length and intensity — next to the flock card, together with your lay results. Create a free account or write to us.
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