1. Jim Webster, Kevin Stafford & Allan Schaefer
Infrared thermography and heart rate variability for non-invasive assessment of animal welfare. ANZCCART 2008
Mairi Stewart
Jim Webster, Kevin Stafford & Allan Schaefer
Agriculture and Agriculture et
Agri-Food Canada Agroalimentaire Canada

2. What is infrared thermography ?
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)

3. You can't hide your lying eyes…
Photo from U.S. Department of Defence Polygraph

4. Approach
Measure responses to routine husbandry procedures used on-farm (eg handling, disbudding)

5. fright

6. Autonomic Nervous System
Parasympathetic
Sympathetic
Restores energy reserves
Mobilises energy reserves
The ANS is made up of two branches, the parasympathetic nervous system and the SNS. The Parasympathetic predominates in a relaxed state and functions to restore energy reserves. For example it functions to slow the heart rate whereas Sympathetic activity has the opposite effect by increasing heart rate and functioning to mobilise energy reserves required during the ‘fight or flight’ reaction…
Relatively few studies use autonomic activity as an assessment of welfare in farm animals mainly because of the cost and difficulties in the measurements available. but we needed another measure of autonomic activity to confirm that the drop in eye temperature was due to vasoconstriction and preferably something non-invasive that wasn’t going to perturb the results.
A common method for measuring autonomic activity that has been used in humans is through heart rate variability.
- vasoconstriction
- secretion of catecholamines
-vasodilation

7. 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

8. Heart rate variability - disbudding - Sympathetic Nervous System Indicator
***

9. Eye temperature - disbudding
baseline LA
Disbud
***
*** *
Time (min)
vasoconstriction

10. Adrenaline challenge – eye temperature
infusion

11. Summary Eye temperature dropped in response to: fright
painful procedure
adrenaline
Evidence that the drop in eye temperature is mediated by sympathetic activity

12. Conclusions
A combination of eye temperature and HRV is a useful non-invasive assessment of autonomic activity.
May be an alternative to invasive methods currently used to assess farm animal welfare.
So in conclusion the gadget turned out to be a little more useful than some us previously suspected … and A combination of eye temperature and HRV is a useful non-invasive assessment of autonomic activity.
May be an alternative to invasive methods currently used such as blood sampling to assess farm animal welfare therefore minimising the impact on animals and the results.

13. Questions?