Cow preference and usage of free stalls versus an open lying area
The aim of this study was to compare free stall housing with access to an identical bedded area without stall partitions. Groups (n = 8) of 12 cows each were provided access to identical pens with free stalls partitions installed or all such partitions removed to create an open lying area. After a 7-d adaptation period, each group was tested on the two treatments for 3 d each, with treatment order counterbalanced between groups. The "no-choice" phase was followed by an 8-d choice phase during which cows had simultaneous access to both options. Behavior was scored using scan sampling at 10 min intervals for 24 h/d. Observations from multiple days and cows were averaged to form a mean value per group for each treatment condition. The effect of housing on cows' behaviors was tested using a mixed model (SAS), with group specified as a random effect and the effect of housing (1 df) tested against the residual error (7 df). During the no-choice phase, cows spent more time lying down (54.3 ± 1.09 vs. 52.0 ± 0.87 %; F1,7=6.7 P<0.037) and standing with all 4 hooves (4.0 ± 0.63 vs. 1.7± 0.49 %; F1,7=22.7, P<0.002) in the open lying area than in the free stall. During the choice phase cows spent a greater proportion of time lying down (30.0 ± 1.09 vs. 24.5± 1.27%; F1,7=10.9 P<0.013) and standing with 4 hooves (2.4 ± 0.48 vs. 0.48± 0.01%; F1,7=22.0, P<0.002) in the open lying area versus the stalls. When provided access to an open lying area cows also reduced the time spent standing in the alley and standing with the front 2 hooves in bedding area, behaviors associated with increased risk of lameness. In conclusion, cows preferred lying and standing in an open lying area than in the free stalls.