Infrared thermography of agonistic behaviour in pigs

Anik Boileau, M Farish, SP Turner, I Camerlink

Research output: Contribution to journalArticle

Abstract

Infrared thermography (IRT) or thermal imaging is increasingly being used as a non-invasive method to gain information on animals’ physiological and emotional state. IRT has the potential to serve as a non-invasive quantitative assessment method but few studies have examined its utility in predicting welfare-relevant outcomes of dynamic scenarios relevant to commercial farming. This study used 1,284 thermal images taken from 46 pigs in a controlled test environment while they engaged in an agonistic encounter (dyadic contest) at 13 wk of age. Images were taken of the complete body from a dorsal perspective. A pilot study indicated that a rectangular thermal window on the back region was the most suitable and reliable area for obtaining temperature data in this situation. From this thermal window, the average, minimum and maximum temperature, standard deviation and coefficient of variation (CV) were obtained. These were analysed in relation to contest phase (from non-contact assessment, through escalated fighting to retreat), fight occurrence, contest duration, contest outcome (winner / loser status) and changes in blood glucose, blood lactate, and skin injuries. Variables showed a strong change in response to the moment of contest resolution (retreat of the loser); temperatures reduced sharply and CV increased, but did not differ between winners and losers. Contests that included a fight showed lower temperatures. Contest duration, body weight and sex only had minor influences on the temperatures. As the drop in temperature at contest resolution was irrespective of contest intensity, and the pattern was similar in winners and losers, this data potentially reflects vasoconstriction as a result of psychological stress rather than solely a physiological change. The study shows that peripheral temperature, as recorded by IRT, responds to the intensity and phases of a contest and may allow new insight into the physiological and welfare outcomes of aggressive behaviour.
Original languageEnglish
Article number112637
JournalPhysiology and Behavior
Volume210
Early online date30 Jul 2019
DOIs
Publication statusPrint publication - Oct 2019

Fingerprint

Agonistic Behavior
Swine
Temperature
Hot Temperature
Controlled Environment
Vasoconstriction
Agriculture
Psychological Stress
Blood Glucose
Lactic Acid
Body Weight
Skin
Wounds and Injuries

Keywords

  • Thermography
  • Emotion
  • Pig
  • Agression
  • Physiology
  • Contest

Cite this

Boileau, Anik ; Farish, M ; Turner, SP ; Camerlink, I. / Infrared thermography of agonistic behaviour in pigs. In: Physiology and Behavior. 2019 ; Vol. 210.
@article{3ab665ef79d74f9ab5402d1382dd57fc,
title = "Infrared thermography of agonistic behaviour in pigs",
abstract = "Infrared thermography (IRT) or thermal imaging is increasingly being used as a non-invasive method to gain information on animals’ physiological and emotional state. IRT has the potential to serve as a non-invasive quantitative assessment method but few studies have examined its utility in predicting welfare-relevant outcomes of dynamic scenarios relevant to commercial farming. This study used 1,284 thermal images taken from 46 pigs in a controlled test environment while they engaged in an agonistic encounter (dyadic contest) at 13 wk of age. Images were taken of the complete body from a dorsal perspective. A pilot study indicated that a rectangular thermal window on the back region was the most suitable and reliable area for obtaining temperature data in this situation. From this thermal window, the average, minimum and maximum temperature, standard deviation and coefficient of variation (CV) were obtained. These were analysed in relation to contest phase (from non-contact assessment, through escalated fighting to retreat), fight occurrence, contest duration, contest outcome (winner / loser status) and changes in blood glucose, blood lactate, and skin injuries. Variables showed a strong change in response to the moment of contest resolution (retreat of the loser); temperatures reduced sharply and CV increased, but did not differ between winners and losers. Contests that included a fight showed lower temperatures. Contest duration, body weight and sex only had minor influences on the temperatures. As the drop in temperature at contest resolution was irrespective of contest intensity, and the pattern was similar in winners and losers, this data potentially reflects vasoconstriction as a result of psychological stress rather than solely a physiological change. The study shows that peripheral temperature, as recorded by IRT, responds to the intensity and phases of a contest and may allow new insight into the physiological and welfare outcomes of aggressive behaviour.",
keywords = "Thermography, Emotion, Pig, Agression, Physiology, Contest",
author = "Anik Boileau and M Farish and SP Turner and I Camerlink",
year = "2019",
month = "10",
doi = "10.1016/j.physbeh.2019.112637",
language = "English",
volume = "210",
journal = "Physiology and Behavior",
issn = "0031-9384",
publisher = "Elsevier",

}

Infrared thermography of agonistic behaviour in pigs. / Boileau, Anik; Farish, M; Turner, SP; Camerlink, I.

In: Physiology and Behavior, Vol. 210, 112637, 10.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Infrared thermography of agonistic behaviour in pigs

AU - Boileau, Anik

AU - Farish, M

AU - Turner, SP

AU - Camerlink, I

PY - 2019/10

Y1 - 2019/10

N2 - Infrared thermography (IRT) or thermal imaging is increasingly being used as a non-invasive method to gain information on animals’ physiological and emotional state. IRT has the potential to serve as a non-invasive quantitative assessment method but few studies have examined its utility in predicting welfare-relevant outcomes of dynamic scenarios relevant to commercial farming. This study used 1,284 thermal images taken from 46 pigs in a controlled test environment while they engaged in an agonistic encounter (dyadic contest) at 13 wk of age. Images were taken of the complete body from a dorsal perspective. A pilot study indicated that a rectangular thermal window on the back region was the most suitable and reliable area for obtaining temperature data in this situation. From this thermal window, the average, minimum and maximum temperature, standard deviation and coefficient of variation (CV) were obtained. These were analysed in relation to contest phase (from non-contact assessment, through escalated fighting to retreat), fight occurrence, contest duration, contest outcome (winner / loser status) and changes in blood glucose, blood lactate, and skin injuries. Variables showed a strong change in response to the moment of contest resolution (retreat of the loser); temperatures reduced sharply and CV increased, but did not differ between winners and losers. Contests that included a fight showed lower temperatures. Contest duration, body weight and sex only had minor influences on the temperatures. As the drop in temperature at contest resolution was irrespective of contest intensity, and the pattern was similar in winners and losers, this data potentially reflects vasoconstriction as a result of psychological stress rather than solely a physiological change. The study shows that peripheral temperature, as recorded by IRT, responds to the intensity and phases of a contest and may allow new insight into the physiological and welfare outcomes of aggressive behaviour.

AB - Infrared thermography (IRT) or thermal imaging is increasingly being used as a non-invasive method to gain information on animals’ physiological and emotional state. IRT has the potential to serve as a non-invasive quantitative assessment method but few studies have examined its utility in predicting welfare-relevant outcomes of dynamic scenarios relevant to commercial farming. This study used 1,284 thermal images taken from 46 pigs in a controlled test environment while they engaged in an agonistic encounter (dyadic contest) at 13 wk of age. Images were taken of the complete body from a dorsal perspective. A pilot study indicated that a rectangular thermal window on the back region was the most suitable and reliable area for obtaining temperature data in this situation. From this thermal window, the average, minimum and maximum temperature, standard deviation and coefficient of variation (CV) were obtained. These were analysed in relation to contest phase (from non-contact assessment, through escalated fighting to retreat), fight occurrence, contest duration, contest outcome (winner / loser status) and changes in blood glucose, blood lactate, and skin injuries. Variables showed a strong change in response to the moment of contest resolution (retreat of the loser); temperatures reduced sharply and CV increased, but did not differ between winners and losers. Contests that included a fight showed lower temperatures. Contest duration, body weight and sex only had minor influences on the temperatures. As the drop in temperature at contest resolution was irrespective of contest intensity, and the pattern was similar in winners and losers, this data potentially reflects vasoconstriction as a result of psychological stress rather than solely a physiological change. The study shows that peripheral temperature, as recorded by IRT, responds to the intensity and phases of a contest and may allow new insight into the physiological and welfare outcomes of aggressive behaviour.

KW - Thermography

KW - Emotion

KW - Pig

KW - Agression

KW - Physiology

KW - Contest

U2 - 10.1016/j.physbeh.2019.112637

DO - 10.1016/j.physbeh.2019.112637

M3 - Article

C2 - 31374228

VL - 210

JO - Physiology and Behavior

JF - Physiology and Behavior

SN - 0031-9384

M1 - 112637

ER -