479 Pain control for the castration of newborn bull calves by elastration

Abstract All methods of castration are known to cause pain regardless of the method, or age of the animal. Our objective was to explore providing pain control for bull calves castrated by elastration prior to 1 wk of age. Singleton, bull calves (n = 85) born at the Ontario Beef Research Centre were enrolled and randomly assigned to 1 of 5 treatment groups at birth: a single dose of oral meloxicam at castration (1ORAL), a dose of oral meloxicam at castration and a second oral dose 1 wk later (2ORAL), a dose of injectable meloxicam at castration (1INJECT), not castrated (SHAM), or castrated without pain control (PAINFUL). Calves were treated within 48 h of birth and followed until weaning. All calves were observed 2 h/d for 13 different pain-associated behaviors (e.g., tail flicks, kicking, licking the scrotum) on the day of castration (d 0), as well as d 1, 2, 7, 8, and 9. To record general activity, from d -1 to d 14 each calf wore an Onset HOBO Pendant G Data Logger attached to one of their hind legs. Calves were weighed weekly until they were turned-out to pasture and thereafter weighed bi-weekly until weaning. Five behaviors were statistically significant between treatment groups. PAINFUL calves had roughly three times the rate of licking (P 0.05) compared with calves in 1ORAL, 2ORAL, and 1INJECT groups, and four times the rate of licking compared with SHAM calves. Additionally, PAINFUL calves had two times the rate of tail flicks (P 0.05) compared with meloxicam-treated calves, and five times the rate of tail flicks compared with SHAM calves. A treatment effect (P 0.05) was observed for standing time, with PAINFUL calves spending the least amount of time standing on average in a 24-h period. No statistical time differences were seen between the remaining treatment groups. No treatment or treatment*time interaction effects were observed for lying time. A tendency was seen for treatment effect on lying time (P = 0.0581), with PAINFUL calves spending the most time lying on average and having a significance difference compared with all other treatment groups (LSM 0.05). No treatment effect was seen for average daily gain up to wk 8, and for final weaning weights. Weight at time of castration was significant (P 0.05); however, calves were not blocked by BW when assigned to treatment. In conclusion, meloxicam-treated calves expressed decreased rates of pain-associated behaviors compared with PAINFUL calves, and BW did not differ at time of weaning. Our results provide evidence that calves castrated by elastration before 1 wk of age and received meloxicam, experience less pain.