Impact of parity on cow stress, behavior, and production at a farm with guided traffic automatic milking systems

Authors: DAVIS, LINDSEY - Clemson University; French, Elizabeth; AGUERRE, MATIAS - Clemson University; AHMED, ALI - Clemson University

Submitted to: Frontiers in Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2023
Publication Date: 12/11/2023
Citation: Davis, L., French, E.A., Aguerre, M.J., Ahmed, A. 2023. Impact of parity on cow stress, behavior, and production at a farm with guided traffic automatic milking systems. Frontiers in Animal Science . https://doi.org/10.3389/fanim.2023.1258935.
DOI: https://doi.org/10.3389/fanim.2023.1258935

Interpretive Summary: The adoption of advanced technology, such as automatic milking systems, has become more widespread across the United States. One advantage is the ability of cows to create individual milking, feeding, and resting schedules apart from their counterparts. However, it is unknown how cow parity affects cow behavior, welfare, and system efficiency. We hypothesized primiparous (PR) cows would spend more time in and around the milking robot (AMS), encounter greater agonistic interactions, and show elevated stress behaviors compared to multiparous (MU) cows. In the current study, primiparous cows spent more time idling in the commitment pen, waiting to enter the milking robot, unlike multiparous cows, while the latter performed more displacement agonistic behaviors and attempted to approach the milking robot gate more frequently. Moreover, primiparous cows showed increased HRV-related stress levels in the commitment pen and milking robot than multiparous cows, spent less total time lying, and performed more frequent and shorter laying bouts compared to the multiparous cows. Overall, findings from the current study suggest that cow parity influenced behavior, activity, and stress indicators of primiparous more than multiparous cows and impacted the overall efficiency and success of the AMS. Separate grouping or advanced training of primiparous cows may be possible interventions to lessen the social competition when milking and reduce possible impacts on their behavior and welfare. However, it should be noted that only one experimental herd and a single barn design were included in the current study, thus, providing a very specific description of events. In the future, the inclusion of numerous experimental herds and differing group sizes may help lead the industry to an ideal solution to promote optimum group mixing and cow behavior within the AMS.

Technical Abstract: The adoption of advanced technology, such as automatic milking systems, has become more widespread across the United States. One advantage is the ability of cows to create individual milking, feeding, and resting schedules apart from their counterparts. However, it is unknown how cow parity affects cow behavior, welfare, and system efficiency. We hypothesized primiparous (PR) cows would spend more time in and around the milking robot (AMS), encounter greater agonistic interactions, and show elevated stress behaviors compared to multiparous (MU) cows. Thus, this study aimed to evaluate the impact of cow parity on behavior and welfare near and inside the AMS. Twenty-four lactating Holstein dairy cows (12 primiparous (3.0 ± 0.2 yr) and 12 multiparous (6.1 ± 1.9 yr)) housed in the LaMaster Dairy Farm AMS facility were marked and observed for 6 consecutive days (91 to 102 of lactation). Focal cows were identified by specific colored paint markings, their milk yield and visits were recorded, and their behavior, heart-rate-variability, and activity were recorded inside the commitment pen (CP) and the AMS. Statistical calculations were performed using JMP Pro 16.1.0, and P = 0.05 was considered significant. Multiparous cows produced more daily milk yield than PR cows (P = 0.021), while parity showed no effect on daily milking frequency or milk yield per visit. Primiparous cows spent significantly more time inside the CP than MU cows (P = 0.001), while MU cows approached the AMS more often than the PR cows (P = 0.030), MU cows displaced other cows more inside the CP than PR cows (P = 0.032). PR cows showed lower RMSSD (P = 0.023) and SDRR (P = 0.012) values than MU cows, whereas MU cows showed a lower LF/HF than PR cows inside the CP (P = 0.003). MU cows spent more time lying (P = 0.003), particularly at night (P = 0.030), than PR cows, while MU cows exhibited more prolonged total lying bouts than PR cows (P = 0.010). Overall, cow parity influenced behavior, activity, and stress indicators of primiparous more than multiparous cows and impacted the overall efficiency and success of the AMS.