Short communication: Changes in heart rate variability of dairy cows during conventional milking with nonvoluntary exit

Abstract

Heart rate variability (HRV), as a physiological measure of animal welfare, was investigated in 36 cows milked in a parallel milking parlor with nonvoluntary exit. Heart rate variability parameters measured during the morning resting (baseline period) were compared with those measured during different stages of the entire milking process. No differences were found in HRV parameters between the baseline period, preparation, and main milking. A considerable reduction in vagal activity was detected during the movement of the cows to the milking parlor (driving) and while cows were in the holding area. The parasympathetic measures of HRV decreased whereas the sympatho-vagal balance increased compared with baseline. The same pattern was observed regarding the stage between removing the teat cups and leaving the milking parlor (waiting). No differences in any sympathetic measures were observed between the baseline period and any of the milking stages. These findings indicate that the milking process itself (preparation and main milking) is not stressful for cows. Decreased parasympathetic activity during driving might be the result of the physical activity of the cows, whereas waiting in the holding area and in the milking stall after milking caused stress for animals.

Heart rate, heart rate variability, faecal glucocorticoid metabolites and avoidance response of dairy cows before and after changeover to an automatic milking system

“…Waiting for exiting the milking stall after the milking has finished is stressful for cows (Kovács et al, 2013). In PARL, it took an inevitably longer time (4.8 ± 1.0 min), due to the individual differences in milk let-down speed, compared to AMS, where it was considerably shorter (0.3 ± 0.15 min).…”

“…Hopster et al (2002) also reported lower HR in the waiting area in AMS, compared to PARL. Stress was presumably a result of aversive handling methods (Pajor et al, 2000) or crowding in the holding area (Morgan and Tromborg, 2007;Kovács et al, 2013).…”

“…During the AMS period, the electrodes were attached in the morning (between 06:30 and 08:00 o'clock) and removed after a 24-h recording session. The electrodes were positioned and fixed as described in our earlier studies (Kovács et al, 2013(Kovács et al, , 2014. The heart rate was recorded continuously after a 2-h acclimatisation period.…”

Fetal heart rate and fetal heart rate variability in Lipizzaner broodmares

“…The measurement of HRV was reported to be an accepted method for assessing the level of stress, as during stress the activity of the sympathetic nervous system increases and certain HRV values change (Kovács et al, 2012;Kovács et al, 2013). According to other authors, however, the HRV values do not change significantly either with age or during pregnancy (Minero et al, 2001;Mohr et al, 2002).…”

“…Data have been published about HRV in pregnant cows as well (Kovács et al, 2012;Kovács et al, 2013). The measurement of HRV was reported to be an accepted method for assessing the level of stress, as during stress the activity of the sympathetic nervous system increases and certain HRV values change (Kovács et al, 2012;Kovács et al, 2013).…”