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Effect of oral meloxicam on indicators of pain following band castration in beef calves
The objective of this study was to evaluate if oral meloxicam could mitigate post-procedural indicators of pain associated with band castration in beef calves. One hundred intact Angus bull calves (BW 299 ± 3.3 kg) were randomly assigned to treatments according to a 2 × 2 factorial design assessing castration method (band castration (B) or sham castration (S)) and provision of a pain mitigating agent at the time of castration(1mg/kg of meloxicam oral suspension (15mg/ml) (M) or non-medicated (N) given an oral saline solution) to yield BM, BN, SM, SN treatments (25 calves/group). Behavioral and physiological indicators of pain were assessed over a 9 wk period post-castration. Animal BW (kg) was recorded weekly to calculate ADG and feed intake (kg/d; FI) daily for all animals over the experimental period. A subsample of 48 calves were randomly selected to obtain more detailed measurements on d 0 and weekly until the end of the study including salivary cortisol (ng/mL), blood cell count (CBC), and gait stride length (cm). In addition, 16 calves (4/treatment) were fitted with data loggers to monitor lying and standing duration (min/d) and number of steps (no./d) taken over a 4 d period post-castration. No differences (P > 0.05) were observed in lying and standing duration, stride length or number of steps between M and S calves from d 0 to 6. Similarly, M and S calves did not differ (P > 0.05) in BW, ADG, FI, or CBC values over the 63 d study. However, a castration × medication × day effect (P = 0.03) was observed for ADG with BM calves tending to have a higher ADG (P = 0.07) than BN calves on d 7. Salivary cortisol concentrations were greater (P < 0.05) in B than S calves from 60 to 120 min following castration but there was no difference (P > 0.05) between M and N calves. Overall, meloxicam administered orally at the time of band castration had little effect on indicators of pain post-castration. However, there was some evidence that ADG was improved in M calves on d 7. More study on the timing of drug administration is required to determine optimal circulating levels relative to the time of the procedure when it may have the greatest benefit.
Keywords: pain mitigation, band castration, meloxicam, beef calves