Autonomic nervous system activity of dairy cows with different temperament and behavioral reactivity

Abstract

The aim of this study was the characterization of cardiac autonomic activity under different conditions in cows with different individual characteristics. For this purpose, we investigated heart rate and ANS-related heart rate variability (HRV) parameters of dairy cows (N = 282) on smallerand larger-scale farms grouped by (1) temperament and (2) behavioural reactivity to humans (BRH). Animals with high BRH scores were defined as impulsive, while animals with low BRH scores were defined as reserved. Cardiac parameters were calculated for undisturbed lying. Sympathetic tone was higher, while vagal activity was lower in temperamental cows than in calm animals during rest. Basal heart rate did not differ between BRH groups. Differences between basal ANS activity of impulsive and reserved cows reflected a higher resting vagal and lower sympathetic activity of reserved animals compared to impulsive ones. These two groupings allowed to draw parallels between personality and ANS activation during both rest and milking in dairy cows.