The effect of omitted milking on the behaviour of cows in the context of cluster attachment failure during automatic milking

In robotic milking there is always a slight chance of failure to attach the milking cluster. Attachment failure is most likely for cows whose udder co nformation is less convenient for robot attachment. In general, after milki ng failure cows try to revisit the milking robot if they are not sent to a separate area. Since it is difficult to estimate the effect of milking fail ure on such a cow and her welfare in conditions of robotic milking, a speci fic 16-day trial was conducted on 12 cows. These cows were milked in a milk ing parlour with six milking stalls. Each afternoon milking, three cows wer e not milked. All the cows were closely observed in the cubicle house for 1 h after the afternoon milking. Thereafter, all cows were brought to the mi lking parlour the third time and the three unmilked cows were milked. In to tal, each cow was observed 12 times after milking and four times after omit ted milking. The following behavioural traits were registered: time budget for the 1 h, occurrence and time until eating, drinking, lying, urination a nd defecation, and aggressive interactions. Milking order was defined on th e basis of how often a cow came to the milking parlour in the first batch o f six cows. Moreover, the data related to the milk yield and the use of the automatic feeding installation with the complete diet were analysed. After omitted milking, only the cows from the first batch stood longer in cubicl es (14.2 min of 1 h) and lay less (5.4 min of 1 h) than milked cows of the same batch (respectively 7.0 min and 16.3 min for standing and lying in cub icles) (P < 0.01). After omitted milking, cows urinated earlier and more fr equently (64.5%) than milked cows (35.3%) (P<0.002) (both batches). There w ere no statistically significant differences in eating time and feed intake after milking and omitted milking. Milk yield per cow averaged 24.9 kg dur ing days with omitted (delayed by 1 h) milking and 25.3 kg during the days without omitted milking(P < 0.05). It was concluded that cows show some sig ns of discomfort after omitted milking (urination); this discomfort seemed to be greater in cows coming earlier to the milking parlour (afterwards the y preferred to stand rather than to lie). The 60% of cases of milk leakage found after omitted milking indicates that failed cluster attachment can be accompanied by an extra risk factor for the occurrence of mastitis. Howeve r. omitted milking as a treatment did not influence feeding and aggressive behaviour or milking order when unmilked cows were brought to the milking p arlour the third time together with the milked cows. Our methods and result s can be useful For estimating the effects of robot milking Failures on a c ow. Future studies should pay particular attention to high-yielding cows an d to longer periods of delayed milking. (C) 2000 Elsevier Science B.V. All rights reserved.