Pharmacokinetics of oral and subcutaneous meloxicam: Effect on indicators of pain and inflammation after knife castration in weaned beef calves

Oral meloxicam is labelled for reducing pain and inflammation associated with castration in cattle in Canada, however, subcutaneous meloxicam is only labelled for pain associated with dis-budding and abdominal surgery. The aim of this project was to determine the pharmacokinetic profile of oral (PO; 1.0 mg/kg BW) and subcutaneous meloxicam (SC; 0.5 mg/kg BW), and to assess the effect of meloxicam on physiological and behavioural indicators of pain associated with knife castration in 7–8 month old calves. Twenty-three Angus crossbred beef calves (328 ± 4.4 kg BW) were randomly assigned to two treatments: PO n = 12 or SC n = 11 administration of meloxicam immediately before knife castration. Physiological parameters included salivary and hair cortisol, substance P, haptoglobin, serum amyloid-A, weight, complete blood count, scrotal and rectal temperature. Behavioural parameters included standing and lying behaviour, pen behaviour and feeding behaviour. Data were analyzed using PROC GLIMMIX (SAS), with repeated measures using mixed procedures including treatment as a fixed effect and animal and pen as a random effect. The pharmacokinetic profile of the drug including area under the curve, volume of distribution and clearance was greater (P < 0.05) in PO than SC calves. After surgery, substance P concentrations, white blood cell counts (WBC), weight and lying duration were greater (P < 0.05) in PO than SC calves, while scrotal circumference was lower (P < 0.05) in PO calves than SC calves. Although statistical differences were observed for pharmacokinetic, physiological and behavioural parameters differences were small and may lack biological relevance.info:eu-repo/semantics/publishedVersio

Effect of meloxicam and lidocaine administered alone or in combination on indicators of pain and distress during and after knife castration in weaned beef calves

To assess the effect of meloxicam and lidocaine on indicators of pain associated with castration, forty-eight Angus crossbred beef calves (304 ± 40.5 kg of BW, 7–8 months of age) were used in a 28 day experiment. The experiment consisted of a 2 × 2 factorial design where main factors included provision of analgesia and local anaesthesia. Analgesia consisted of: no-meloxicam (N; n = 24) single s.c. administration of lactated ringer’s solution and meloxicam (M; n = 24) single dose of 0.5 mg/kg of s.c. meloxicam. Local anesthesia consisted of: no-lidocaine (R; n = 24) ring block administration of lactated ringer’s solution or lidociane (L; n = 24) ring block administration of lidocaine. To yield the following treatments: no meloxicam + no lidocaine (N-R; n = 12), no meloxicam + lidocaine (N-L; n = 12), meloxicam + no lidocaine (M-R; n = 12) and meloxicam + lidocaine (M-L; n = 12). Salivary cortisol concentrations were lower (lidocaine × time effect; P 0.05) were observed for average daily gain (ADG), weights or feeding behaviour. Overall, both lidocaine and meloxicam reduced physiological and behavioural indicators of pain. Although there was only one meloxicam × lidocaine interaction, lidocaine and meloxicam reduced physiological and behavioural parameters at different time points, which could be more effective at mitigating pain than either drug on its own.info:eu-repo/semantics/publishedVersio

012 Meloxicam and temperament effects on growth performance and indicators of pain in knife or band castrated calves housed on pasture

The objective of this study was to evaluate the effect of castration method, meloxicam, and temperament on growth performance and indicators of pain in band- or knife-castrated beef calves. Seventy-two crossbred Angus calves (76 ? 2 d of age and 134.5 ? 20.30 kg BW) were randomly assigned to treatments according to a 3 ? 2 factorial design assessing castration technique (CAST; knife [K], band [B], or sham castration [S]) and drug administration (DRUG; single subcutaneous injection of meloxicam at the time of castration [0.5 mg Metacam/kg BW] or single subcutaneous injection of saline solution as control). Calves were managed in 2 groups (GROUP) of 36 to be castrated on 2 separate days, 2 wk apart. Calves were housed on pasture with ad libitum access to water. Temperament was assessed by measuring flight speed (FS; m/s); faster animals indicated more excitable temperament. Growth performance was assessed using ADG (kg/d). Substance P (SP; pg/mL) and stride length (SL; cm) were used as physiological and behavioral indicators of pain, respectively; greater SP and SL values indicated greater and lower pain levels, respectively. Initial BW and FS were collected on d ?6, ?1 (prior to castration day), and 0 (immediately prior to castration) as baseline measurements and on d 6, 13, 20, 34, 48, and 62 after castration (DAY). Calves were blocked by the average FS and BW obtained on d ?6 and ?1. Data was analyzed using a mixed-effects model including CAST, DRUG, DAY, and their interactions as fixed effects and GROUP as a random effect. The average baseline measurements of BW, the average of all FS measurements, and the average of SP or SL obtained on d ?1 and 0 were used as covariates. Growth performance was greater (P < 0.05) in S (1.33 ? 0.03 kg/d) than in K and B (1.21 ? 0.03 and 1.22 ? 0.03 kg/d, respectively). For every 1 m/s increment in FS, SP decreased by 8.7 pg/mL (P < 0.05). There was no effect of CAST, DRUG, or FS on SL. As expected, both knife- and band-castrated calves had reduced ADG compared with S calves. Faster FS was associated with lower pain levels, indicating that temperament can affect physiological measures. A single subcutaneous injection of meloxicam had no effect on growth performance or the indicators of pain used in this studyPeer reviewe