Preliminary Study on the Relationship Between Skin Temperature of Piglets Measured by Infrared Thermography and Environmental Temperature in a Vehicle in Transit - Veterinary Science - page 196

Fig. 32.2 Trends of the maximum skin temperatures and environmental temperatures inside the
vehicle during the journeys of July and September
respectively. Data from both the months were tested up to a 5 polynomial
regression, which did not increase the R 2 value obtained by the simple regression.
It is interesting that the angular coefficients of the two equations were very similar
(+0.1972 and +0.1992). Thus, in the range of temperatures recorded during the two
transports, an increase of 1 C inside the vehicle resulted in an increase of the
maximum skin temperature of 0.2 C. Figure 32.2 illustrates the trends of the
maximum skin and internal vehicle temperatures during the two journeys. There
was a comparable trend between skin and vehicle temperatures when the vehicle
temperatures exceeded 25 C and 20 C during the journeys of July and September,
respectively.
32.4 Discussion
To our knowledge, this is the first study using infrared thermography to continu-
ously measure the changes in pig body-surface temperatures during transport. This
technique could be applied to controlled transport conditions, even if there are some
practical constraints due to the positioning of the camera and the particular envi-
ronment in which the measurements are performed. Importantly, the vibrations of
the vehicle did not influence the quality of the images recorded; however, a
loosening of some mechanical parts of the camera occurred. The linear relationship
observed between skin and environmental temperatures in the vehicle confirms the
results obtained in an environmental chamber by Loughmiller et al. ( 2001 ) where,
between 10 C and 32 C, this relationship had an R 2 value of 0.97.
The results of this study demonstrate that with infrared thermography it is
possible to record the variation of body-surface temperatures and their relationship
with the changes of the environmental temperature inside the vehicle. This tech-
nique, coupled with deep temperature recording systems, will help to better under-
stand the adaptive efforts of pigs in response to the environmental conditions
experienced during transport and, specifically, extreme temperatures.