Behavioral pattern of dairy cows milked in a two-stall automatic milking system with a holding area

Behavioral pattern was investigated in dairy cows milked in an automatic milking system (AMS) in contrast to cows milked in a conventional milking parlor. Forty-eight Holstein cows were allocated to two groups of 24 animals. The two groups were housed in adjacent free stall pens. Both groups were milked twice a day at 0500 and at 1500 for 30 d before commencement of the experiment, one in a two-stall AMS (AMS Group), the other in a 16-stall herringbone parlor (Parlor Group). The respective holding areas were used to encourage cows to enter the milking compartments. All cows consumed total mixed rations ad libitum, provided once a day between 0500 and 0600 in indoor feed bunks. Cows in both groups were allowed daily access to two adjacent outdoor paddocks from 1030 to 1230. Behavioral observations were carried out in the free stall barn from 0400 to 0900 and from 1250 to 1900 for 30 d. The number of cows lying down, standing in the stalls, standing in the passageway, and eating was recorded every 10 min. Analyses of variance were used to compare time serial changes in behavioral states between groups. Although the time serial changes in the behavioral states were not different between groups after returning from paddocks, they became significantly different between groups for all four recorded behavioral states after the onset of milking. Ethograms during the 11-h observation period showed that cows in the AMS group spent less time eating at the feed bunk and standing in the stalls to compensate for the longer time standing in the holding area. The results indicate that AMS milking with a holding area affects social synchronization of cows eating and resting and reduces time spent eating significantly more than parlor milking.