Influence of Different LED Light Colour Temperatures on the Preference Behaviour of Weaned Piglets

Abstract

This study investigates the effect of different LED lighting colour temperatures on the preference behaviour of 4-week-old weaned piglets. A total of 32 piglets were housed in two replications in an experimental pen area with four identically equipped pen compartments connected two by two. Each pen unit offered a compartment set to a colour temperature of 3000 kelvin and another set to 6500 kelvin, at 80 lux during the day. Each piglet could freely choose between the two compartments by using a passageway. Over a period of five weeks, the behaviours “lying”, “eating” and “activity” were video recorded for 72 h during the 1st, 3rd and 5th week of the experiment. The location of the piglet in the pen and its behaviour were determined by using time sampling. In the first week, the piglets preferred the colour temperature of 3000 K to perform all behaviours. In the following weeks this preference decreased. Results also show that feed consumption and soiling of the pens were higher under 6500 K. Pigs can differentiate between the different colour temperatures and use them for different behaviours. This can be used to divide pens into functional areas in order to better suit the behavioural needs of pigs.

Lying, Feeding and Activity Preference of Weaned Piglets for LED-Illuminated vs. Dark Pen Compartments

“…For this experiment, the same preference test room as the one described in Götz et al [ 27 ] was used. Briefly, the room comprised 4 identically equipped 4.17 m 2 pen compartments connected two by two (referred to as pen units) by a passageway ( Figure 1 ).…”

“…Briefly, the room comprised 4 identically equipped 4.17 m 2 pen compartments connected two by two (referred to as pen units) by a passageway ( Figure 1 ). The passageways were 47 cm × 35 cm large and obscured by three hanging opaque black PVC strips (see [ 27 ] for more details) in order to separate the two compartments between which pigs could choose. One side of the room was illuminated permanently (24 h) with 600 lx and a colour temperature of 6500 kelvin, while the other half was permanently dimmed to almost 0 lx.…”

“…One side of the room was illuminated permanently (24 h) with 600 lx and a colour temperature of 6500 kelvin, while the other half was permanently dimmed to almost 0 lx. Each pen compartment consisted of a concrete slatted floor covering half of the surface, a heating plate (400 mm × 600 mm; MIK International THERMO E, MIK International, Ransbach-Baumbach; Germany) and plastic floor grids covering the other half ( Figure 1 , [ 27 ]). A sisal rope attached to the wall as well as a chain with a piece of soft wood hanging from the ceiling at the height of the piglets were also available in each pen compartment as enrichment for the pigs.…”

“…In order to have the two extreme illuminance levels of 600 and ~0 lx, in line with Götz et al [ 27 ], the preference test room was separated in the middle by a wooden framework consisting of squared timber pieces (4 cm high × 2 cm wide). The wooden framework was then covered with opaque fabric (Sunblock blackout fabric; Tuchler; Vienna, Austria).…”

“…In view of the lack of specificity in lighting recommendations for pigs, the “Innovative light-emitting diode (LED) illumination for increased requirements in livestock animals” project was developed to measure pig behaviours under different LED lighting regimens. Thus, in a previous study [ 27 ], the preference choice behaviour of piglets between two colour temperatures (3000 vs. 6500 kelvin) at the same illuminance level (80 lx during the day and 4 lx at night) was investigated. We found that the piglets initially preferred the colour temperature of 3000 K to lie down, but this preference then decreased with time.…”