The present invention relates to a LED luminaire (10) for use in a livestock barn. The LED luminaire comprises a base plate (13) provided with at least one first LED arrangement (21 -25) configured to, in operation, emit light which simulates daylight lighting conditions. The first LED arrangement comprises a plurality of LEDs of a first type (28), which has at least one peak wavelength in the wavelength range between 500 and 600 nm, and at least one LED of a second type (27), which is a blue LED with its peak wavelength in the wavelength range between 440 and 480 nm. The luminaire is provided with an optical system (30) configured in such a way that the intensity of light emitted by the LEDs is distributed according a distribution (40) which has its peak intensity at an angle of more than zero degrees from the optical axis of the luminaire.
