Time-budget constraints for cows with high milking frequency on farms with automatic milking systems

Adequate lying times and feed consumption are essential for the welfare and performance of dairy cows. The time budget of cows housed in barns with an automatic milking system (AMS) might be constrained in several ways. Cows with a high milking frequency might also have to visit the AMS at night, possibly interfering with their night-time lying behavior. Moreover, competition for access to the AMS might cause some cows to spend more time waiting in front of the milking unit, resulting in a lower milking frequency. In the present study, the individual total duration of stay and time spent per visit in the feeding, lying and waiting area, as well as lying behavior, was therefore investigated in the daytime and throughout the night in relation to milking frequency. A total of 138 focal cows (day of lactation: 1-200) housed on 4 Swiss working farms with an AMS were automatically tracked for 48 h. Individual lying times were recorded over 7 days with data loggers. The daily milking frequency was calculated from the AMS records and included as a continuous explanatory variable in linear mixed-effects models. Time spent in the waiting area at night increased with increasing milking frequency. In addition, cows with a relatively high milking frequency had shorter daytime lying bouts, and spent less time in the lying area per visit during the daytime as well as at night. The same individuals also visited the feeding area for shorter times during the day, and on average remained longer per visit in the waiting area at night. The daily time budget of cows with a relatively low milking frequency was not adversely affected. Cows with a relatively high milking frequency may face some trade-offs in their time budget allocation, since the increased time spent by them in the waiting area at night as well as their shorter lying bouts might affect their welfare, health and performance. Nevertheless, the overall daily time budget for lying and feeding, and hence the welfare of cows with both a relatively high or low milking frequency, suffered no obvious adverse effects. (C) 2014 Elsevier B.V. All rights reserved.