Characteristics of Dairy-Cow Eye Surface Temperature Measured by Infrared Thermography

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1 Federal Department of Economic Affairs, Education and Research EAER Agroscope Characteristics of Dairy-Cow Eye Surface Temperature Measured by Infrared Thermography Pascal Savary Clermont-Ferrand, 3 September th International Conference on the Assessment of Animal Welfare at Farm and Group Level

2 Background Dairy farmers frequently report problems during milking How do these problems manifest themselves? Cow behaviour: Defecation Restlessness Knocking off the milking unit Cow physiology: Incomplete emptying of udder Increased somatic cell count in the milk 2

3 Background Are milking problems an animal welfare concern? To what extent do milking machines or milking parlour environments affect the welfare of dairy cows? What workable method could be used to objectively detect acute stress in cows in a milking-parlour environment? 3

4 Infrared Thermography and Eye Temperature Infrared thermography is a user-friendly, non-invasive method for detecting surface-temperature fluctuations The lacrimal caruncle region of the eye is rich in capillary beds innervated by the sympathetic nervous system, and responds to changes in blood flow (Stewart et al., 2007) A drop in eye temperature may indicate acute stress in animals (Schaefer et al., 2006; Stewart et al., 2007) Rapid decreases in eye temperature of K and -0.5 K were measured for the true disbudding of dairy calves without a local anaesthetic (Stewart et al., 2007), and for dairy cows in a chute (Helmreich, not published), respectively 4

5 Temperature variations can be caused by other factors than stress 5

6 Factors Influencing Body Surface Temperature Wind speed Solar loading Photo: Agroscope 6

7 Factors Influencing Body Surface Temperature Atmospheric humidity Distance between camera and object Air temperature 7

8 Aim of the Study To quantify the effects of: Anatomical symmetry between left and right eye Angle of recording Correct distance between camera and eye Surface-temperature fluctuations in non-stressed dairy cows over a short period of time Circadian rhythm and cow activity 8

9 Materials and Methods Animals: 12 lactating cows (6 first and 6 subsequent lactations) Activity and measurement times: Feeding (9.00); Milking (4.30 and 16.00); Lying in cubicle (6.00, and 16.30) Repeated measurements: 3 times within a period of 1 ½ min. Measurements were undertaken on two consecutive days (repetition) Camera position: lateral and palmar Distance between camera and eye: 0.5 m, 1.0 m and 1.5 m Statistics: Generalised linear mixed models 9

10 Materials and Methods ThermaCAM TM E4 (FLIR System) 10

11 Thermograms 11

12 Eye surface temperature [ C] Augentemperatur [ C] Symmetry and Angle of Recording Linkes Left eye Auge Right Rechtes eye Auge Left Linkes eye Auge Right Rechtes eye Auge Lateral Lateral Palmar Frontal Angle of recording p = ***; Symmetry p = n.s. 12

13 Effect of Wind Speed Cubicle housing Neck rail Left eye Right eye Measured wind speed between km/h Feeding table 13

14 Augentemperatur [ C] Eye surface temperature [ C] Distance between Camera and Eye m 1.0 m 1.5 m Distance p = *** 14

15 Eye surface temperature [ C] Augentemperatur [ C] Fluctuations over a Short Period :30 1:40 0: Repetition Fressen Melken Liegen 2 3 Feeding Milking Lying in cubicle Activity p = ***; Repetition p = n.s. 15

16 Eye surface temperature [ C] Augentemperatur [ C] Herzfrequenz [Schläge/min] Heart rate [bpm] Circadian Rhythm and Cow Activities C 20 C 22 C 16 C 21 C 20 C 1 9: : : : : :30 12 Feeding Fressen Melken Milking Lying Liegen in cubicle Circadian rhythm p = ***; Activities p = *** 16

17 Conclusions Without air movement or wind speeds below 4 km/h, eye surface temperature is symmetrical between the left and right side Lateral recording angles together with a distance of 0.5 m between camera and animal yield greater precision Eye surface temperature does not fluctuate over a short period of approx. 2 minutes Time of day only affected lying behaviour, and was probably not caused by circadian rhythm Taking these parameters into account, the method can be used to analyse acute stress in animals during milking 17

18 Thank you for your attention! Pascal Exigences Savary Agroscope systèmes de traite 18