Replication Data for: The effect of placement and group size on the use of a mechanical brush by groups of lactating dairy cattle

Mechanical brushes are often provided on dairy farms to facilitate grooming. However, current brush designs do not provide data on their use and little is known about the effects of group size and placement of brushes within the pen. The objectives of this study were to automatically detect brush use in cow groups and investigate the influence of (1) group size and the corresponding cow-to-brush ratio and (2) brush placement in relation to the lying stalls and the feeding and drinking areas. We measured brush use in groups of 60, 48, 36, and 24 cows with the brush placed either in the alley adjacent to the feed bunk and water trough or in the back alley. Cows used the brush longer when placed in the feed/water alley compared to when placed in the back alley. Average brush use per cow increased when cows were housed in smaller groups but the brush was never in use more than 50% of the day regardless of group size. We conclude that brush use in-creases when availability is increased and when the brush is placed closer to feed and water.