Training dairy heifers with positive reinforcement: Effects on anticipatory behavior.

Dairy cattle are often restrained for veterinary procedures, but restraint can cause fear responses that can make the procedure challenging for both the animal and the human handler. Positive reinforcement training (PRT) is used in other species to reduce fear responses and there is now evidence that this can also facilitate handling in cattle. The objectives of this study were to test the effect of PRT on anticipatory and play behavior in dairy heifers. We predicted that heifers trained with PRT would show more anticipatory and play behaviors than control heifers in the period before gaining access to a chute. We used 20 heifers (5 ± 0.6 mo old) that had been habituated to the chute area and had previous experience with handling. Heifers were randomly assigned to 2 treatments: control (n = 10) and PRT (n = 10). Positive reinforcement training heifers were subjected to a training protocol that included standard farm handling techniques, as well as target training with food reinforcement. Control heifers were moved to the chute using standard farm handling techniques only. As predicted, PRT heifers performed more behavioral transitions (7.6 ± 0.77 vs. 4.4 ± 0.57 transitions for control heifers; F1,9 = 21.99, P < 0.01), and specifically performed more locomotory play such as jumping (2.1 ± 0.30 vs. 0.4 ± 0.19 jumps; F1,9 = 57.18, P < 0.01) and running (2.0 ± 0.40 s vs. 0.5 ± 0.16 s; F1,9 = 20.73, P < 0.01). These results indicate that PRT results in heifers having a more positive emotional state in anticipation of handling, and support the use of training to improve the welfare of dairy cattle.

Effects of positive reinforcement training for heifers on responses to a subcutaneous injection.

Cattle are subjected to routine procedures that require restraint and close contact to humans, which are both potentially aversive to the animal. Positive reinforcement training techniques may affect how animals perceive and respond to these procedures. The objectives of the current study were to describe a positive reinforcement regimen used to train cattle to stand still for a sham injection, and to assess the effects of this training on the responses to an actual injection. Eight "agency" heifers were trained, over an average of 85 ± 4.6 sessions, with positive reinforcement (i.e., animals received a grain reinforcer for desired behaviors) to enter a headlock, and they were habituated with counterconditioning and desensitization to a sham injection (i.e., animals were gradually exposed to the sensation of the sham injection, paired with access to grain). The headlock remained open at all times to allow heifers to leave. Eight "habituation" heifers were exposed to the treatment area and headlock for an equal number of sessions and duration as agency heifers, and 7 "naïve" heifers were provided no exposure to the treatment area. Once agency heifers tolerated the sham injection, all animals received a 1-mL subcutaneous injection of 0.9% NaCl while in the head lock (habituation and naïve heifers were locked in but agency heifers were free to withdraw). Immediate responses to the injection, starting with tenting of the skin, were video recorded and summarized as a reactivity score, which included the number of steps, head tosses, and backing-up movements; we also recorded the latency to approach the treatment area and headlock for 3 d after the injection. Of the agency heifers, 5 remained standing for the actual injection, whereas 3 heifers moved out of the headlock for a brief period (1, 3, and 5 s, respectively). Habituation heifers had a higher reactivity score [17.5 (10.5-28); median (IQR)] than agency [6 (2-13.5)] and naïve heifers [6 (5-7)]. Averaged over the 3 d after injection, agency heifers showed lower latencies to come to the treatment area [8.7 (7.2-24.2) s] than did habituation [50.5 (28-60) s] and naïve [53.7 (18-60) s] heifers. Agency heifers voluntarily entered the headlock within 1.3 (1-1.5) s but, with one exception, none of the other heifers did so within the allowed 15 s. These results indicate that dairy heifers can be trained with positive reinforcement and counterconditioning to voluntarily accept a painful procedure, and that training can reduce avoidance behaviors during and after the procedure.

Behavioral changes associated with fever in transition dairy cows.

Dairy cows are often diagnosed with fever without showing clinical symptoms of disease. The aim of this study was to investigate changes in feeding, social, and lying behaviors of cows with fever but without clinical disease, as compared with healthy cows. After parturition, dairy cows of mixed parities were housed in a dynamic group of 20. In the freestall pen, cows had access to 12 electronic feed bins, 2 electronic water bins, and 24 lying stalls. Feeding and social behaviors were recorded using the electronic feed bins, and lying behaviors were measured using electronic data loggers attached to the cow. Rectal body temperature was assessed on a daily basis, and fever defined as a body temperature >39.5°C. All cows were examined for metritis every third day after calving, and all other diseases (e.g., mastitis, ketosis) were diagnosed as per farm protocol. Cows with multiple days of fever (n = 8) and cows with 1 d of fever (n = 18) that were not diagnosed with a clinical disease were compared with a matched sample of healthy cows (i.e., cows that were not clinically ill and never had a fever recorded) of the same parity (categorized as primiparous vs. multiparous). Feeding, social, and lying behaviors were compared for the first 2 d of fever in cows with multiple days of fever, and the day of fever in cows with 1 d of fever. Cows of both fever groups spent less time feeding compared with controls (135 vs. 181 ± 7.6 min/d for multiple fever days, and 158 vs. 185 ± 9.7 min/d for 1 d of fever). Cows with 1 d of fever ate at a faster rate (109 vs. 91 ± 5 g/min) and had a lower number of replacements at the feed bunk (actor replacements: 9.7 vs. 14.6 ± 1.7 no./d; reactor replacements: 11.1 vs. 15.9 ± 1.6 no./d) compared with healthy controls. Overall, cows with fever showed behavioral changes such as decreased feeding time that are consistent with sickness responses described in other species.

Claw horn lesions in mid-lactation primiparous dairy cows under pasture-based systems: Association with behavioral and metabolic changes around calving.

The objectives of this study were to describe the lying behavior of primiparous dairy cows under pasture-based systems during the pre- and postcalving period and characterize the association of lying behavior and analytes related to energy metabolism during this period with claw horn disruption lesion development later in lactation. Our convenience sample included 39 primiparous Holstein cows from 3 commercial farms that were assessed for body condition score (BCS; 5-point scale, 0.25-point increments) and had blood collected at wk -3, -2, -1, 1, 2, and 3 relative to calving date. Blood samples were assayed for nonesterified fatty acids, ß-hydroxybutyrate (BHB), and cholesterol concentrations. Electronic data loggers (HOBO Pendant G Acceleration, Onset Computer Corporation, Bourne, MA) recorded lying behavior at 1-min intervals from 3 wk before calving to 3 wk after calving. Starting at 4 wk after calving and until 16 wk after calving, cows were examined for claw lesions at approximately 4-wk intervals. Sole lesions and white line lesions were scored on a 0 to 10 scale. Of the 39 primiparous cows, 19 cows scored 0 at all exams during the entire study period and 20 cows had at least 1 severe lesion (score ≥4) between 8 and 16 wk after calving. Time spent lying before calving averaged 10.3 ± 0.3 h/d, but declined to 7.3 ± 0.3 h/d after calving (least squares means ± standard error). At calving, we noted an increase in the number of lying bouts (12.9 ± 0.45 bouts/d) compared with the pre- and postcalving averages of 11.6 (±0.53) and 9.1 (±0.47) bouts, respectively. Cows that developed claw lesions later in mid lactation spent less time lying down than cows without lesions during wk 3 after calving compared with healthy cows (7.29 ± 0.22 vs. 8.51 ± 0.16 h/d). Lesion cows had fewer lying bouts per day, and these bouts were of longer duration than no-lesion cows after calving. Increased odds of lesion were found to be associated with shorter lying times and fewer number of lying bouts during wk 3 (odds ratio = 1.23). Nonesterified fatty acids (747 ± 58 vs. 990 ± 86.85 µmol/L) and BHB (0.77 ± 0.06 vs. 0.60 ± 0.04 mmol/L) concentrations during wk 1 were greater in cows that developed claw lesions relative to cows that did not develop lesions. The BHB concentrations also remained higher in wk 2 for cows that developed claw lesions (0.63 ± 0.04 vs. 0.46 ± 0.03 mmol/L) compared with cows that did not develop any lesions. Cows that developed lesions experienced greater losses in BCS from wk -3 to 3 than cows without lesions (0.74 ± 0.01 and 0.61 ± 0.01 BCS change, respectively). In summary, changes in lying behavior and energy metabolic status after calving were associated with claw horn disruption lesions in mid-lactation primiparous cows under pasture-based systems.

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.

Behavioral changes before metritis diagnosis in dairy cows.

Metritis is common in the days after calving and can reduce milk production and reproductive performance. The aim of this study was to identify changes in feeding and social behavior at the feed bunk, as well as changes in lying behavior before metritis diagnosis. Initially healthy Holstein cows were followed from 3 wk before to 3 wk after calving. Behaviors at the feed bunk were recorded using an electronic feeding system. Lying behavior was recorded using data loggers. Metritis, based upon the characteristics of vaginal discharge at d 3, 6, 9, 12 and 15 after calving, was diagnosed in 74 otherwise healthy cows. Behavior of these cows, beginning 2 wk before calving until the day of diagnosis, was compared with 98 healthy cows (never diagnosed with any health disorder, including ketosis, mastitis, and lameness) during the transition period. During the 2 wk before calving, cows later diagnosed with metritis had reduced lying time and fewer lying bouts compared with healthy cows. In the 3 d before clinical diagnosis, cows that developed metritis ate less, consumed fewer meals, were replaced more often at the feed bunk, and had fewer lying bouts of longer duration compared with healthy cows. We concluded that changes in feeding as well as social and lying behavior could contribute to identification of cows at risk of metritis.

Changes in feeding, social, and lying behaviors in dairy cows with metritis following treatment with a nonsteroidal anti-inflammatory drug as adjunctive treatment to an antimicrobial.

Dairy cows with metritis display sickness behaviors, and nonsteroidal anti-inflammatory drugs (NSAID) have the potential to reduce these responses. The objective of this study was to investigate changes in feeding, social, and lying behaviors in dairy cows with metritis that had been treated with the NSAID meloxicam. After parturition, cows were housed in a dynamic, mixed-parity group of 20 animals with access to 12 electronic feed bins, 2 electronic water bins, and 24 lying stalls in a freestall pen. Every third day after parturition, vaginal discharge was evaluated to diagnose metritis based on the presence of foul smell and characteristic visual appearance. When diagnosed with metritis, animals (n = 87) were randomly allocated to receive either a single dose of meloxicam (0.5 mg/kg of body weight subcutaneously) or a placebo solution. All metritic animals received an antimicrobial (ceftiofur) for 5 d. We measured feeding and social behaviors at the feed bunk, as well as lying behaviors, and assessed within-cow changes from the day before to the day of (d 0) NSAID treatment, and from the day before to d 1 to 5 after treatment. Generally, behaviors changed around the day of diagnosis of metritis. Compared with the placebo group, cows that received meloxicam had a greater increase in the number of visits to the feeder, but tended to show less of an increase in dry matter intake and feeding time. These differences did not persist beyond 24 h after NSAID treatment. We observed no differences in changes in number of meals and feeding rate on d 0, but from d 1 to 5 cows treated with meloxicam had a lesser decrease in the number of meals and tended to have a greater decrease in feeding rate than did placebo-treated cows. In multiparous cows on d 0 and from d 1 to 5, meloxicam treatment was associated with decreased lying times. In primiparous cows, lying time changes were similar between treatments on d 0, but lying times increased more on d 1 to 5 for meloxicam than for placebo cows. Overall, cows changed the number of lying bouts on d 0, and this increase tended to be smaller for the meloxicam cows. There were no treatment differences in changes of social behavior. In summary, we observed inconsistent and generally small effects of a single dose of meloxicam in addition to antimicrobial therapy on the behavior of cows with metritis.

Parity differences in the behavior of transition dairy cows.

During the transition period, around the time of calving, cows experience a suite of stressful events, including regrouping, diet changes, parturition, and the onset of lactation. These changes may be more difficult for primiparous cows that have not had these experiences previously. The objective of this study was to compare feeding, social, exploratory, and lying behaviors of primiparous and multiparous cows during the transition period. Thirty-eight healthy primiparous and 62 healthy multiparous dairy cows were housed in mixed-parity groups of 20 with access to 12 electronic feed bins from 3wk before to 3wk after calving. Primiparous cows had lower dry matter intake, spent more time feeding, ate more slowly, visited the feeder more frequently, and explored their feeding environment more compared with multiparous cows. Primiparous cows also lay down more frequently, but for shorter periods, such that total lying time did not differ between these parity classes. Primiparous cows were also replaced at the feeder more often than multiparous cows. These results show how the behavior of primiparous and multiparous cows differs during the transition period, and support the idea that primiparous cows may benefit from different management during this period.