Effect of Transition from Conventional Milking to Robotic Milking on Teat Skin and Teat End Condition

The introduction of an automated milking system into a dairy herd could possibly affect teat skin and teat end condition. Under a voluntary milking system (VMS™, DeLaval) the cows will be milked more frequently than under a conventional milking system. The effect of transition from conventional milking to robotic milking was examined in a clinical trial while using a high emollient iodine teat dip (Proactive Plus™, DeLaval).

Forty lactating cows and heifers from a high yielding dairy herd were randomly allocated to a control and VMS group, each group containing 9 heifers and 11 multiparous cows. In the VMS group, robotic milking was initiated during the study period, while in the control group conventional milking was continued during the whole study period. Teat skin condition (TSC) and teat end condition (TEC) were evaluated weekly on quarter level for all 40 cows from 5 weeks before until 8 weeks after initiation of automated milking, using a classification system going from 1 (smooth teat skin and end sphincter) to 5 (severely damaged teat skin and end). The same teat dip was used on all teats of all cows during the whole study period. Statistical analysis was performed using the Generalized Estimating Equations (GEE) methodology for longitudinal data, leaving the correlation matrix unstructured (S-Plus 2000^® for Windows).

In total, 2045 teat skin scores and 2034 teat end scores were recorded during the study period. Results of mean teat skin scores (MTSS) and mean teat end scores (MTES) per group (± SEM), prior and after initiation of robotic milking, and mean milking frequencies (MMF) (± SEM) per day after initiation of robotic milking for the VMS group, are given in Table 1:

Table 1

When considering TSC, the VMS group showed consistent scores from before and during milking with the VMS™. The control group did not perform as well as the VMS group (P < 0.001), but cow handling may have been a contributing factor. Rear quarters had a better TSC than front quarters (P < 0.001). When only considering the animals in the VMS group, more frequent milking resulted in a higher score (P < 0.001). It was concluded that the transition to robotic milking did not influence TSC much, as teat skin scores in the VMS group were stable during the study period. Any potential effect of more frequent milking on the TSC may have been mitigated using the teat dip.

For TEC, the results were mixed. The multiparous cows in the VMS group performed better than their control group (P < 0.001). The heifers in the VMS group showed a increased score compared to their controls (P < 0.001), but the mean score was still very good. When only considering the animals in the VMS group, more frequent milking resulted in a higher teat end score (P < 0.001). Transition from conventional to automated milking influenced TEC of the VMS heifers negatively, when compared with the control heifers. The opposite was true for the VMS multiparous cows, as their TEC was better than the control multiparous cows.