Lameness and lying behavior in grazing dairy cows.

Lameness is a serious welfare issue for dairy cows. To date, the majority of studies have focused on its effect on health and behavior at the herd level. The objectives of this study were to identify (1) between-cow and (2) within-cow changes in lying behavior associated with consistent and changing lameness status in grazing dairy cows. Previous studies of lying behavior in grazing dairy cows have not considered the effect of precipitation, so a third aim was to determine the effect of precipitation on lying behavior. A total of 252 dairy cows from 6 pasture-based farms in southern Brazil were gait scored weekly to assess lameness using a 5-point scale [1-5, numerical rating score (NRS)] for 4 consecutive weeks. Cows were considered to have consistent lameness if they were scored as lame (NRS ≥3) on each of the 4 visits and considered to have a changing lameness status if scored as being nonlame (NRS <3) on at least 1 of the 4 visits. Cows classified as having a changing lameness status were further classified as developed, recovered, or inconsistent. Lying behavior (daily lying time, mean lying bout duration, and daily number of lying bouts) was recorded continuously for 3 wk using leg-mounted accelerometers. Cow-level variables included parity, days in milk, and body condition score. Regional precipitation and temperature were recorded hourly. Because only 1 primiparous cow was identified as lame at each of the 4 visits, the between-cow analysis of lameness was run on multiparous cows only. The overall prevalence of clinical lameness on the first visit was 39%, with development and recovery rates of 16 and 10% over the 4 visits, respectively. The between-cow effect of consistent lameness status on daily lying time and number of lying bouts was dependent on precipitation; consistently lame cows had reduced lying time and lying bouts on days with rain compared with days without rain. There was no within-cow effect of changing lameness status on any of the lying behaviors. Precipitation was associated with decreased daily lying time, increased mean lying bout duration, and decreased daily number of lying bouts. The results of this research provide the first evidence that the effect of consistent lameness status on lying behavior is associated with rainfall in grazing dairy cows. Future work measuring lying behavior of grazing dairy cows should include precipitation as a covariate.

Dairy cow preference and usage of an alternative freestall design.

Freestall housing for dairy cows was created to reduce the amount of bedding and labor needed to keep stalls clean. However, some aspects of stall design may restrict stall usage by cows. The aim of this study was to assess dairy cow preference and usage of a conventional stall (with a neck rail and metal stall dividers) and an alternative stall design with no neck rail or stall dividers other than a wooden board protruding slightly (8cm) above the lying surface. In the no-choice phase of the study, 48 cows were randomly assigned to 8 groups (of 6 cows each); groups were alternately allocated to the 2 treatments. Each group was observed for 7 d on one treatment and then switched to the alternate treatment for 7 d. For the choice phase (also 7 d), groups in adjacent pens were merged (to form 4 groups, each with 12 cows) and cows had free access to both treatments within the merged pen. In the no-choice phase, cows spent more time standing with 4 hooves in the alternative versus conventional freestall (0.60±0.06 vs. 0.05±0.06h/d), but stall designs had no effect on time spent lying down (13.2±0.4 vs. 12.9±0.4h/d). In the choice phase, cows spent more time lying down in the conventional freestall (9.4±0.8 vs. 4.1±0.8h/d) and more time standing with all 4 hooves in the alternative stall (0.24±0.03 vs. 0.02±0.03h/d). These results illustrate how different stall design features can affect different types of stall use; the more open design facilitated standing fully in the stall, but the protruding partitions likely made the stall less suitable for lying.

Lying behavior and postpartum health status in grazing dairy cows.

Many cows have difficulty making the transition from pregnancy to lactation, as evidenced by the high incidence of disease that occurs in the weeks after calving. Changes in lying behavior can be used as an indicator of illness, yet no work to date has evaluated this relationship in dairy cows on pasture. The objectives of this study were to describe the lying behavior of grazing dairy cows during the first 3 wk after calving and determine the relationships between transition diseases and lying behavior. Our convenience sample included 227 multiparous and 47 primiparous Holstein cows from 6 commercial farms. Cows were recruited as they calved during the spring calving period. Electronic data loggers (Hobo Pendant G Acceleration, Onset Computer Corp., Pocasset, MA) recorded lying behavior at 1-min intervals. Diseases were recorded up to 21 d in milk, and cows were subsequently categorized into 3 health categories: (1) healthy, not lame and had no other signs of clinical (retained placenta, milk fever, metritis, mastitis) or subclinical (ketosis, hypocalcemia) postpartum diseases; (2) lame, identified as being clinically or severely lame with no other signs of clinical or subclinical postpartum disease; and (3) sick, diagnosed as having one or more clinical postpartum diseases (with or without a subclinical disease) but not lame. This last group was further divided into 2 groups: those that were diagnosed with a single clinical health event and those diagnosed with more than one clinical event. Lying behavior differed between primiparous and multiparous cows; primiparous cows divided their lying time into more bouts than did multiparous cows (9.7 ± 0.54 vs. 8.4 ± 0.26 bouts/d) and spent less time lying down than multiparous cows (7.5 ± 0.38 h/d vs. 8.5 ± 0.19 h/d). Lying behavior was also affected by illness; primiparous cows that developed more than one clinical disease, excluding lameness, spent more time lying, and tended to have longer lying bouts in the days following calving compared with healthy cows; multiparous severely lame cows spent more time lying down (1.7 h longer per day) compared with multiparous cows that were nonlame. Clinically lame cows had fewer lying bouts per day and these bouts were of longer duration than healthy nonlame cows. In summary, changes in lying behavior after calving were associated with postpartum health status in grazing dairy cows.

Overstocking reduces lying time in dairy cows.

Our objective was to understand the effect of overstocking on the lying and standing behavior of dairy cattle. We manipulated freestall availability by providing 12, 11, 10, 9, or 8 freestalls to 12 cows (n = 4 groups, 12 cows/group), thus creating stocking levels of 100, 109, 120, 133, and 150%, respectively. Treatments were applied for a week at a time in a switchback design. Each group returned to the 100% stocking level after exposure to the other treatments. In addition to lying and standing behavior, we measured each cow's ability to displace others from the freestall to understand the interaction between social status and response to overstocking. When groups of cows had fewer stalls available, they spent less time lying down. There was no effect of overstocking on time spent standing with only the front legs in the stall. Instead, cows compensated for the reduced lying times by spending more time outside of the stall. When fewer stalls were available, animals were more likely to be displaced from stalls. The cow's ability to displace others from the stalls, however, did not explain the magnitude of their reduction in lying time when provided with fewer freestalls. Due to increased competition for stalls, cows lay down sooner at 150% than at the 100% level. Stall use was more uniform across time and across stalls within the pen when fewer freestalls were available. In conclusion, when cows had access to fewer freestalls, there was increased competition for stalls, increased time standing outside the stalls, and reduced lying time.