Influence of passive training of primiparous cows and its interaction with individual cow personality on adaptation to and performance on an automated milking system.

The primary study objective was to determine how previous exposure to an automated milking system (AMS) pen via an exposure period to the AMS pen before first milking, giving cows the opportunity for previous exposure and social transmission, influences the adaptation of primiparous dairy cows to the AMS. A secondary objective was to determine whether certain personality types adapt better if they experienced an exposure period or not. Thirty-two primiparous Holstein dairy cows were enrolled as pairs in the study at 147 ± 6.97 DIM (mean ± SD) and were assessed for personality traits using a combined arena test comprised of 3 parts: a novel arena test, a novel object test, and a novel human test. Cows were allocated into 1 of 2 treatments within pair (n = 16 per treatment): control (CON; no exposure period), and exposure (EXP; had a 48-h exposure period in a free-flow AMS pen before first milking in the AMS, a form of passive training). During the exposure period, the EXP cows were kept in the AMS pen for 48 h, while being milked in the parlor 2 × /d, where they were exposed to the AMS pen, pen mates, were able to voluntarily explore the AMS, and were able to watch other adapted cows in the pen utilize the AMS. At the end of the 48-h period, both cows within the pair were milked in the AMS for the first time and remained in the AMS pen thereafter. Milking variables (visits, kickoffs, milk flow), behavior (activity, rumination, feeding), and yield were recorded for the exposure period (d -2 and -1) and the first 21 d in the AMS. Cows that experienced the exposure period had fewer meals (8.4 vs 12.1 meals/d; SE = 0.7) on d 0 (first day of milking in the AMS) compared with CON cows. From d 2 to 20 of milking in the AMS, the EXP cows had more frequent visits to the AMS (6.8 vs 5.5 visits/d; SE = 0.28), tended to have a 1.4 × lesser odds (odds ratio [OR] = 0.72; 95% CI = 0.51-1.01) of having a daily fetching event, and had greater milk yield compared with CON cows (33.5 vs 32.5 kg/d; SE = 0.29). The personality traits of boldness and activeness were identified in the cows. Personality was only associated with outcome variables for cows that experienced the exposure period, where the more bold EXP cows had lesser odds of experiencing a rejection (OR = 0.40; 95% CI = 0.26-0.59), voluntary visit (OR = 0.40; 95% CI = 0.26-0.59), and voluntary milking (OR = 0.34; 95% CI = 0.22-0.53), while more active EXP cows had greater odds of experiencing a voluntary visit (OR = 4.52; 95% CI = 1.22-16.81) compared with less bold and less active EXP cows. Overall, the results demonstrate that passive training, specifically an exposure period in the AMS pen before first milking, can improve adaptation to the AMS and milk letdown, and in turn milk yield. In addition, individual cow personality influenced how well those cows that experienced the exposure period adapted to the AMS.