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Transcript of Agriculture and Agriculture et
Agriculture and Agriculture etAgri-Food Canada Agroalimentaire Canada
Infrared thermography and heart rate
variability for non-invasive assessment of
animal welfare.
ANZCCART 2008
Mairi Stewart
Jim Webster, Kevin Stafford & Allan Schaefer
•Measures emitted radiated heat (represents 40-60% of heat loss from an animal)
•Non-invasive – images collected from a distance
•Can detect changes in heat loss during stress (due to regulation of peripheral blood flow)
What is infrared thermography ?
Autonomic Nervous System
Restores energy reserves
Mobilises energy reserves
Parasympathetic Sympathetic
-vasodilation - vasoconstriction
- secretion of catecholamines
What is heart rate variability?• Non-invasive
• Cardiac interbeat (RR) interval = time between successive R waves
• Provides more accurate measure of stress than heart rate
• Allows measurement of sympathetic and parasympathetic responses
Components of the ECG
0.0
1.0
2.0
3.0
4.0
5.0
6.0
Control Disbud only Local only Disbud + local
Ch
an
ge
in L
F/H
F r
atio
Heart rate variability - disbudding- Sympathetic Nervous System Indicator
***
36.6
37
37.4
37.8
38.2
-25 -20 -15 -10 -5 0 5 10 15
Time (min)
Ma
x e
ye
te
mp
era
ture
(oC
)
Control
LA only
Disbud only
LA + Disbud
Eye temperature - disbudding
******
*
baseline LA Disbud
vasoconstrictionTime (min)
Adrenaline challenge – eye temperature
37.7
37.8
37.9
38
38.1
38.2
-15 -10 -5 0 5 10 15
Time (min)
Eye
tem
pera
ture
(oC
)
Epinephrine
Saline
infusion
Summary
• Eye temperature dropped in response to:• fright • painful procedure• adrenaline
• Evidence that the drop in eye temperature is mediated by sympathetic activity
Conclusions1. A combination of eye temperature and HRV is a
useful non-invasive assessment of autonomic activity.
2. May be an alternative to invasive methods currently used to assess farm animal welfare.