Postpartum Stressors Cause a Reduction in Mechanical Brush Use in Dairy Cows

SIMPLE SUMMARY: Dairy cows face many stressors in the weeks immediately before and after calving. Reduced expression of low-resilience behaviors, such as the use of a mechanical brush, can be used to make inferences about affective states. Our study aimed at assessing the effects of stressors associated with parturition by following mechanical brush use after calving and after separation from their calf. We found that cows reduced their use of the brush postpartum. We also found that separation from the calf induced a reduction in brush use, suggesting that it has negative effects on cows. ABSTRACT: Dairy cows are often subjected to multiple post-partum stressors but how these stressors impact cows’ affective states remain poorly understood. Negative affective states are often associated with reduced expression of low-resilience behaviors, so we explored whether cows would reduce their use of a brush after calving. Before calving, cows were offered the opportunity to use a mechanical brush once a week for 10 min. In Experiment 1, we explored whether cows reduced their use of a mechanical brush after parturition (compared to prepartum values) when subjected to the myriad of stressors typically experienced by cows at this time. In Experiment 2, we assessed the effect of cow–calf separation. Results from Experiment 1 showed that cows displayed a reduced brush use following parturition compared to the week before calving. In Experiment 2, we showed that cows given more time to bond with their calf, and who were separated more recently from their calf, showed a more pronounced reduction in brush use. Cows provided part-time contact with their calf for 29 days also reduced their brush use when they were permanently separated from their calf on day 30 after calving. These results suggest that cows experienced anhedonia and point to new directions for research on dairy cow affective states.