Cow preference and usage of free stalls compared with an open pack area.

Free-stall housing systems are designed to provide a comfortable and hygienic lying area, but some aspects of stall design may restrict usage by cows. The aim of this study was to compare free-stall housing with a comparable lying area (open pack) without stall partitions. We predicted that cows would spend more time lying down and standing in the bedded area when provided access to an open pack than when in free stalls. We also predicted that cows would spend less time standing outside of the lying area and less time perching with the front 2 hooves in the lying area when using the open pack. Groups (n = 8) of 12 cows each were provided access to either the open pack or stalls. After a 7-d adaptation period, each group was tested sequentially in the 2 treatments for 3 d each. This no-choice phase was followed by an 8-d choice phase during which cows had simultaneous access to both treatments. During the no-choice phase, cows spent more time lying down (13.03 +/- 0.24 vs. 12.48 +/- 0.24 h/d) and standing with all 4 hooves in the bedded area (0.96 +/- 0.12 vs. 0.41 +/- 0.12 h/d) of the open pack than in the stalls. During the choice phase, cows spent more time lying down (7.20 +/- 0.29 vs. 5.86 +/- 0.29 h/d) and standing with all 4 hooves in the bedded area (0.58 +/- 0.07 vs. 0.12 +/- 0.07 h/d) of the open pack than in the stalls. In both the no-choice (1.66 +/- 0.24 vs. 0.55 +/- 0.24 h/d) and choice (0.55 +/- 0.07 vs. 0.29 +/- 0.07 h/d) phases, cows spent more time standing with just 2 hooves in the stalls than in the open pack. In conclusion, cows spent more time lying and standing with all 4 hooves in the bedded open pack than in the stalls. Additionally, cows spent more time standing in the alley and standing with just the front 2 hooves on the bedding in the stalls than in the bedded open pack; increased standing time on wet concrete is a known risk factor for lameness.