Effect of oral meloxicam administration on growth performance and behavior of pre-weaning age calves following band castration.

The objective of this study was to determine if oral meloxicam (M; a nonsteroidal anti-inflammatory drug) administered at castration to pre-weaning age calves affected average daily gain (ADG) or behavior. Prior to castration (d -14), Angus bulls were weighed and randomly assigned to be band castrated (BAN; n = 8; age = 90.2 ± 6.5 d; BW = 146.3 ± 11.4 kg; scrotal circumference = 16.0 ± 0.5 cm) or castrated with M (BAN + M; n = 9; age = 102.1 ± 6.2 d; BW = 146.0 ± 7.7 kg; scrotal circumference = 16.1 ± 0.3 cm). Six bulls selected to remain bulls based on pedigree and phenotype were maintained in the same pasture (BULL; age = 104.2 ± 6.1 d; BW = 172.1 ± 8.7 kg; scrotal circumference = 17.5 ± 0.4 cm). On d 0, BAN and BAN + M had a rubber band applied tightly around the scrotum, and BAN + M also received oral M (2 mg/kg BW). On d 1, 14, and 28, animals were weighed and a blood sample was collected to determine circulating concentrations of haptoglobin and fibrinogen. Data loggers were affixed to the legs of calves immediately prior to castration (d 0) to record behaviors [mean lying time (h/d), mean lying bouts (n/d), and steps (n/d)] at 1-min intervals and removed on d 28. Behavior and plasma data were tested for effect of treatment, day, and treatment × day interaction, and ADG data were tested for effect of treatment, period (d -14 to 1, d 1 to 14, and d 14 to 28), and treatment × period interaction using JMP procedures for repeated measures (SAS Inst. Inc., Cary, NC). BULL in period d 0 to 14 had greater ADG than all other treatment period combinations, and BULL had greater ADG than BAN or BAN + M overall (P < 0.05). There was no effect of M treatment on circulating concentrations of fibrinogen or haptoglobin (P > 0.05). On d 7 and 15, BAN took more steps than BAN + M (P < 0.05). BAN + M had more lying bouts than BAN on d 13 and 14 (P < 0.05). Overall, M administration had no effect on ADG post-castration and only had minor impacts on behavior in calves band castrated pre-weaning.