Lighting for poultry and livestock houses: requirements for luminaires

Why a livestock house is different

A luminaire in a livestock house has a hard life. The air carries ammonia from manure, humidity is high and there is a constant haze of dust from feed and bedding. After every batch the building is hosed down with a pressure washer and usually disinfected.

A standard indoor luminaire does not last long under those conditions. Ammonia attacks unprotected aluminium and plain steel, water creeps in past the gasket and a layer of dust on the diffuser quickly costs a noticeable share of the light output. A livestock luminaire therefore has to meet four requirements: a sealed housing that survives cleaning, materials that tolerate ammonia, a light level that suits the species and a control system that dims without flicker.

IP65, IP67 or IP69K: which rating for which building

The IP rating tells you how the luminaire copes with cleaning. IP65 protects against dust and water jets from an ordinary hose and is adequate in dry buildings that are only rinsed at low pressure. IP67 covers temporary immersion to 1 metre, but says nothing about high-pressure jets. IP69K is the rating for pressure washing: tested with water at 80 degrees Celsius at 80 to 100 bar from close range.

For broiler houses, pig units and milking parlours that are washed down after every batch we recommend IP69K. For a naturally ventilated cubicle house with limited cleaning, IP65 is usually sufficient. The TRIVO range offers both: linkable linear luminaires in IP65 and IP69K versions of 40 W delivering 6,000 lumens.

Look beyond the IP rating at the materials: a polycarbonate housing and diffuser, stainless steel clips and a gasket that tolerates disinfectants. Avoid bare aluminium and galvanised parts in the animal area.

How many lux for each species

The light level is not a matter of taste: part of it is laid down in law and part is determined by production and animal health. Guide values at animal height, measured at floor or feed level:

• Broilers: at least 20 lux during the light period under the European welfare directive, often 30 to 40 lux in the first days to guide the chicks to feed and water.
• Laying hens: 10 to 20 lux along the feed line, evenly distributed to avoid dark corners and floor eggs.
• Pigs: at least 40 lux for a minimum of 8 hours a day under European rules, 100 lux or more in farrowing houses and wherever stock is inspected.
• Dairy cattle: 150 to 200 lux for 16 hours a day under a long-day regime, then 6 to 8 hours of rest below 50 lux, which research has associated with a higher milk yield.
• Milking parlour and treatment area: 200 to 500 lux, because people work with the animals here and need to judge udders and skin properly.

Uniformity matters more than the average. A building with 180 lux under the fittings and 60 lux between them unsettles the animals. Aim for a minimum to average ratio of at least 0.5 and have the layout calculated before you order.

Light programmes and dimming

Poultry, and to a lesser extent pigs, are kept on a light programme: fixed light periods, a simulated dawn and dusk of 15 to 30 minutes and, in the chick phase, a reduction from 40 to 20 lux or lower. That calls for luminaires that dim smoothly and deeply, to below 5 per cent, without pulsing at low levels or switching off with a jump.

When choosing the driver, check the lower limit of the dimming curve. Many standard drivers stop at 10 per cent, too bright for a dusk phase in a poultry house. Ask for the dimming curve and test it with a lux meter at animal height. For control, DALI-2 is the most flexible option: each luminaire or group gets its own address, the programme runs from the climate computer or a separate controller and can be changed later without touching the wiring. TRIVO is available with a DALI-2 driver, so the linear luminaires run directly within the light programme. Where no programme is needed, such as in a cubicle house, a time switch or a built-in sensor is enough.

Colour temperature and flicker-free light

Animals see differently from people. Poultry perceive flicker above 100 Hz, where the human eye stops at around 60 to 90 Hz. A luminaire that looks steady to us can visibly blink to chickens, causing restlessness and feather pecking. Choose drivers with low ripple on the LED current (flicker percentage below 5 per cent), in the dimmed state as well. Amplitude dimming or PWM at a frequency of several kilohertz is the safest choice.

Colour temperature preferences differ by species. Broiler houses often use 2700 to 3000 K because warm light keeps the birds calmer. For laying hens and pigs 3000 to 4000 K is common. Dairy cattle respond well to daylight-like light of 4000 to 5000 K under a long-day regime. For the milking parlour choose 4000 K with a colour rendering of Ra 80 or higher so that skin and milk look natural.

TRIVO linear luminaires in practice

Most livestock buildings are lit with waterproof linear luminaires running lengthways, 2.5 to 4 metres high between the trusses. TRIVO is built for exactly that: 20 to 60 W at 140 to 150 lumens per watt, so a 40 W luminaire gives roughly 6,000 lumens. The luminaires are through-wired: one supply cable from fitting to fitting, no junction boxes in the building. The housing opens without screws, so driver and module stay accessible without tools, even after years in a damp environment.

As a worked example, for indication only: a cubicle house of 50 by 12 metres at 150 lux needs, with a maintenance factor of 0.8 for a dirty environment, in the region of 30 luminaires of 40 W in three rows. A broiler house at 20 lux needs a fraction of that, but there the dimming range and uniformity decide the choice. Feed stores or a mill with a dust explosion risk call for luminaires from the EXORA range for zone 21 or 22. For the yard and the access road, floodlights from FLUX or street luminaires from VIA on a TURRIS steel column complete the picture.

Frequently asked questions