Effects of metritis on stall use and social behavior at the lying stall.

Metritis in dairy cows has been associated with changes in behavior at the feed bunk, but little is known about the effects on behavior at the lying stall. The aim of this study was to investigate stall use by primiparous dairy cows diagnosed with metritis, specifically time spent in the stall, social interactions at the stall, and lying-related behaviors. After parturition, primiparous cows were housed in a mixed-parity pen with a constant group size of 20. Cows had access to 12 electronic feed bins, 2 electronic water bins, and 24 lying stalls. Four cameras installed above the experimental pen allowed for observation of cows in the feeding and lying area. Every 3 d after parturition, cows were examined for metritis by evaluation of the visual appearance and olfactory character of vaginal discharge. Cows diagnosed with metritis (n = 16) were compared with healthy individuals (i.e., cows without metritis or other clinical disease, n = 16). Healthy individuals were selected based on data availability, body weight, and calving date and, based on these criteria, paired with metritic cows. Video of the 3 d before diagnosis (d -3 to d -1) in the metritic animals (and video from the corresponding days in milk for paired healthy cows) were used to measure behavior. Behaviors assessed included those in the stall (lying, perching, and standing fully in the stall), social behaviors (when a cow either displaced or was displaced by another cow; i.e., actor and reactor replacements), and lying-related behaviors (including visits when the cow entered and left the stall without lying down, aborted lying events when behaviors indicative of the onset of a lying bout were not followed by the cow lying down, and latency to lie down, defined as the time between an aborted lying event and the first lying bout). Cows with metritis spent more time standing fully in the stall on all 3 d, resulting in more time spent standing on d -2 and -1. Cows with metritis tended to have more aborted lying events on d -2, and significantly more on d -1. Cows with metritis tended to be replaced more often at the lying stall on d -3 and tended to have a longer latency to lie down on d -2. We observed no differences between health groups in the number of actor replacements or the number of visits to the stall. In summary, cows with metritis spent more time standing fully in the lying stall and had more aborted lying events. These results suggest that primiparous cows with metritis may be identified by altered behavior at the lying stall.