2.2. Procedure
2.2.1. Habituation
Following the 7-day acclimatisation period, on days 8 and 9,
the hens were gradually habituated to the presence of a human
with a thermal camera (FLIR ThermaCAM E4) sitting on a chair for
4 h each day in their floor pen.
2.2.2. Order of testing
Following the two habituation days, days 10 and 11 were testing
days. Ten of the hens were tested on day 10 and nine on day 11. To
counteract the effects of possible variation in temperature due to
circadian rhythms, hens were randomly assigned to either i) have
their baseline temperature measured in the morning and their handling
and holding box temperature measured in the afternoon (n = 10)
of the same day or ii) vice versa (n = 9). For handling, the order in
which the hens were caught was determined using a random number
generator.
2.2.3. Baseline
A thermal imaging camera (ThermaCam E4, FLIR) was used to
capture a thermal image of either side of each hen's head whilst they
were exhibiting each of three naturally occurring behaviour patterns
within their floor pen: 1) standing with head up, 2) eating from the
feeder and 3) pecking at the ground. The camera was set up at a distance
of 1 m from one of the feeders and the thermal images were
taken whilst the hens performed the different behaviours whilst adjacent
to the feeder. The thermal camera set to an emissivity of 0.96 and
the ambient temperature of the room was maintained at 23 °C.
A period of approximately 3 h was sufficient to obtain one clear
image per hen per each of the three behaviours.