The objectives of this study were to (1) describe the calving location of dairy cattle given access to a pasture and barn; (2) identify factors associated with calving location; and (3) compare the lying and exploratory behavior of cows in the 24 h before calving and a previous day. Seventy-two Holstein dairy heifers and cows (n = 36 nulliparous and n = 36 primiparous and multiparous combined) were housed in a covered bedded-pack barn (167.4 m 2 ) with free access to 2.1 ha of pasture. The composition of the group was dynamic, because cows were moved in weekly at 19 ± 6 d [mean ± standard deviation (SD)] before their calving date, and were removed immediately after calving. To facilitate data collection, we divided the environment into 9 sections, including the barn (section 1; 167.4 m 2 ), 7 sections of open pasture (sections 2 to 8; 2,402 ± 60 m 2 ), and 1 section of pasture surrounded by natural forage cover (section 9; 3,593 m 2 ). We then collapsed these 9 sections into 3 distinct areas for further analysis: the barn, open pasture, and natural forage cover. Animals were fitted with accelerometers to measure lying time, lying bout duration, lying bouts, and steps for the 24 h before calving (calving day) and a similar 24 h period 4 to 11 d (median = 7) before calving (baseline day). We included parity (nulliparous vs. primiparous and multiparous) and heat stress [no heat stress = temperaturehumidity index (THI) ≤68 vs. heat stress = THI >68 and ≤79] in all analyses; we included time of day and group composition as additional factors that may have affected calving location. We determined exploratory behavior using 10 min instantaneous scan sampling collected from video. At each scan, we recorded the section (1 to 9) the cow or heifer was located in, and then calculated the minimum number of sections that could be crossed between successive scans. Of the total sample, 39% calved in the barn, 26% calved in the open pasture, and 35% calved in the area with natural forage cover. Nulliparous heifers and those calving when heat stress was low (THI ≤68) selected the area with natural forage cover more frequently than the barn. On the calving day, cows spent more time lying down with more short bouts of lying, and crossed more sections compared with the baseline day. Steps were affected by an interactive effect of day, parity, and heat stress; nulliparous heifers took more steps on the calving day during conditions of heat stress compared with no heat stress. Results indicate that cows and heifers had different preferences for their environment at calving, and when provided access to pasture, both changed their lying and exploratory behavior on the day of calving compared with a previous day.

Dairy cows housed in tiestalls are restricted to one space; therefore, this space should be designed to accommodate all the activities cows need to perform. Lying is a very important behavior for dairy cows as well as a critical measure in the assessment of stall designs, to ensure that the cows' needs for resting space are met. The objective of this study was to determine if increasing tiestall width alters the lying behavior of lactating dairy cows. Two treatments were compared: the current recommendation (139 cm) and a double stall (284 cm). Sixteen cows were blocked by parity and lactation stage, then randomly allocated to a treatment and a stall within 1 of 2 rows in the research barn, for 6 wk. The average stall length was 188 cm. Leg-mounted accelerometers were used to record lying behaviors. Cows were video-recorded 24 h/wk using surveillance cameras positioned above the stalls. Video data from wk 1, 3, and 6 were extracted at a rate of 1 image/min and analyzed by a trained observer to assess the position and the location of the cow's body, head, and limbs during the lying hours. Lying behaviors and frequency of each position and location were analyzed in SAS (SAS Institute Inc., Cary, NC) using a mixed model in which treatment, block, and week were included as fixed factors, and cow and row as random factors. Multiple comparisons were adjusted using the Scheffé method. Results indicate that cows in double stalls fully extended their hindlimbs more often than single stall cows (21.7 vs. 7.6% of lying time). Cows in double stalls also intruded in the neighboring stalls with their hindlimbs less often (1.3 vs. 14.7% of lying time), instead positioning them inside their own stall more often (92.7 vs. 84.6% of lying time). Use of the second stall in the double stall group totaled 11.6, 5.1, 33.8, and 18.0% of lying time, respectively, for the head, front legs, hind legs, and body. Total lying time was not statistically different between double (716 min/d) and single stall (671 min/d) groups. Contacts with stall hardware during lying-down movements were also less frequent in double stalls (43.1 vs. 77.1% of lying events) compared with single stalls. These results suggest that dairy cows housed in double stalls modified their resting habits and used the extra space made available to them. Increasing stall width beyond the current recommendation is likely to benefit the cows by improving their ability to rest.