Biology Reference
In-Depth Information
(Knowles and Warriss 2007 ). The thermal state of the pig during transport is
particularly difficult to assess because it is dependent on the combined effects of
heat and humidity, external environmental conditions, and vehicle ventilation. The
measure of body temperatures is particularly relevant to the welfare assessment of
pigs during transport, but this parameter is difficult to measure during transit.
Traditional tools used for body-temperature measurements, such as rectal
thermometers, require restraining the animal, and can be used only before and
after transport. Recently, Mitchell et al. ( 2005 ) continuously monitored deep body
temperatures during pig transport using a data logger inserted surgically in the
peritoneum. This technique is very promising, but it is applicable only on very few
subjects who play the role of “sentinels.” In the last two decades, infrared thermog-
raphy (IRT) has been applied to pigs for detecting superficial body temperatures
(Stewart et al. 2005 ). This technique is based on the detection of thermal energy
emitted by a body that is converted into an electronic signal that, in turn, is
processed by software to produce digital images. Images are produced using a
color scale to highlight areas of different temperatures, thus illustrating the thermal
gradient of the examined body with an accuracy of 0.1 C. Infrared thermography
does not require any contact and is, therefore, a noninvasive technique that can
record measurements on subjects that are difficult to reach or approach, or that are
in motion. The purpose of this study was to both continuously measure the
thermometric profile of piglets during a long journey and evaluate its relationship
with the temperature inside the vehicle.
32.2 Materials and Methods
This study was authorized by the Ethical Committee of the University of Bologna.
During two 14-h journeys in July and September 2009, skin temperatures were
measured by infrared thermography. A total of 12 piglets, six on each trip, were
examined. A thermo-camera, Avio TVS 500 (Nec Avio, Dusseldorf, Germany),
was placed in front of and above the pens during the first and second journeys,
respectively. The camera was set with an emissivity of 0.98 and placed at a distance
of 2 m from the subject during the first and 1 m during the second journey. Air
temperature calibration was performed automatically by the instrument. On both
journeys, the compartment examined was in the front of the deck on the right side of
the vehicle. The positioning of the instrumentation required 1.8 m between the floor
and the ceiling. Thus, the available volume of the deck was very wide and natural
ventilation was not used. Temperature and relative humidity were continuously
recorded by a thermo-hygrometer (HOBO Pro v2 loggers, Onset Computer Co.,
Bourne, USA) located inside the compartment housing the piglets.
The average weight of piglets transported was 10.88
1.97 kg in the first trip
and 8.08
0.74 kg in the second. More than 4,000 thermal images were recorded
during the journeys and were analyzed using Goratec Thermography Studio
Professional software (Goratec Technology, Erding, Germany). The maximum
Search WWH ::




Custom Search